def __init__(self):
# wavelength
self.wave = Neutron()
# sample
self.sample = Sample()
# aperture
self.aperture = Aperture()
# detector
self.detector = Detector()
# 2d image of the resolution
self.image = []
self.image_lam = []
# resolutions
# lamda in r-direction
self.sigma_lamd = 0
# x-dir (no lamda)
self.sigma_1 = 0
#y-dir (no lamda)
self.sigma_2 = 0
# 1D total
self.sigma_1d = 0
self.gravity_phi = None
# q min and max
self.qx_min = -0.3
self.qx_max = 0.3
self.qy_min = -0.3
self.qy_max = 0.3
# q min and max of the detector
self.detector_qx_min = -0.3
self.detector_qx_max = 0.3
self.detector_qy_min = -0.3
self.detector_qy_max = 0.3
# possible max qrange
self.qxmin_limit = 0
self.qxmax_limit = 0
self.qymin_limit = 0
self.qymax_limit = 0
# plots
self.plot = None
# instrumental params defaults
self.mass = 0
self.intensity = 0
self.wavelength = 0
self.wavelength_spread = 0
self.source_aperture_size = []
self.source2sample_distance = []
self.sample2sample_distance = []
self.sample_aperture_size = []
self.sample2detector_distance = []
self.detector_pix_size = []
self.detector_size = []
self.get_all_instrument_params()
# max q range for all lambdas
self.qxrange = []
self.qyrange = []
def __init__(self):
# wavelength
self.wave = Neutron()
# sample
self.sample = Sample()
# aperture
self.aperture = Aperture()
# detector
self.detector = Detector()
# 2d image of the resolution
self.image = []
self.image_lam = []
# resolutions
# lamda in r-direction
self.sigma_lamd = 0
# x-dir (no lamda)
self.sigma_1 = 0
#y-dir (no lamda)
self.sigma_2 = 0
# 1D total
self.sigma_1d = 0
self.gravity_phi = None
# q min and max
self.qx_min = -0.3
self.qx_max = 0.3
self.qy_min = -0.3
self.qy_max = 0.3
# q min and max of the detector
self.detector_qx_min = -0.3
self.detector_qx_max = 0.3
self.detector_qy_min = -0.3
self.detector_qy_max = 0.3
# possible max qrange
self.qxmin_limit = 0
self.qxmax_limit = 0
self.qymin_limit = 0
self.qymax_limit = 0
# plots
self.plot = None
# instrumental params defaults
self.mass = 0
self.intensity = 0
self.wavelength = 0
self.wavelength_spread = 0
self.source_aperture_size = []
self.source2sample_distance = []
self.sample2sample_distance = []
self.sample_aperture_size = []
self.sample2detector_distance = []
self.detector_pix_size = []
self.detector_size = []
self.get_all_instrument_params()
# max q range for all lambdas
self.qxrange = []
self.qyrange = []
class ResolutionCalculator(object):
"""
compute resolution in 2D
"""
def __init__(self):
# wavelength
self.wave = Neutron()
# sample
self.sample = Sample()
# aperture
self.aperture = Aperture()
# detector
self.detector = Detector()
# 2d image of the resolution
self.image = []
self.image_lam = []
# resolutions
# lamda in r-direction
self.sigma_lamd = 0
# x-dir (no lamda)
self.sigma_1 = 0
#y-dir (no lamda)
self.sigma_2 = 0
# 1D total
self.sigma_1d = 0
self.gravity_phi = None
# q min and max
self.qx_min = -0.3
self.qx_max = 0.3
self.qy_min = -0.3
self.qy_max = 0.3
# q min and max of the detector
self.detector_qx_min = -0.3
self.detector_qx_max = 0.3
self.detector_qy_min = -0.3
self.detector_qy_max = 0.3
# possible max qrange
self.qxmin_limit = 0
self.qxmax_limit = 0
self.qymin_limit = 0
self.qymax_limit = 0
# plots
self.plot = None
# instrumental params defaults
self.mass = 0
self.intensity = 0
self.wavelength = 0
self.wavelength_spread = 0
self.source_aperture_size = []
self.source2sample_distance = []
self.sample2sample_distance = []
self.sample_aperture_size = []
self.sample2detector_distance = []
self.detector_pix_size = []
self.detector_size = []
self.get_all_instrument_params()
# max q range for all lambdas
self.qxrange = []
self.qyrange = []
def compute_and_plot(self,
qx_value,
qy_value,
qx_min,
qx_max,
qy_min,
qy_max,
coord='cartesian'):
"""
Compute the resolution
: qx_value: x component of q
: qy_value: y component of q
"""
# make sure to update all the variables need.
# except lambda, dlambda, and intensity
self.get_all_instrument_params()
# wavelength etc.
lamda_list, dlamb_list = self.get_wave_list()
intens_list = []
sig1_list = []
sig2_list = []
sigr_list = []
sigma1d_list = []
num_lamda = len(lamda_list)
for num in range(num_lamda):
lam = lamda_list[num]
# wavelength spread
dlam = dlamb_list[num]
intens = self.setup_tof(lam, dlam)
intens_list.append(intens)
# cehck if tof
if num_lamda > 1:
tof = True
else:
tof = False
# compute 2d resolution
_, _, sigma_1, sigma_2, sigma_r, sigma1d = \
self.compute(lam, dlam, qx_value, qy_value, coord, tof)
# make image
image = self.get_image(qx_value, qy_value, sigma_1, sigma_2,
sigma_r, qx_min, qx_max, qy_min, qy_max,
coord, False)
if qx_min > self.qx_min:
qx_min = self.qx_min
if qx_max < self.qx_max:
qx_max = self.qx_max
if qy_min > self.qy_min:
qy_min = self.qy_min
if qy_max < self.qy_max:
qy_max = self.qy_max
# set max qranges
self.qxrange = [qx_min, qx_max]
self.qyrange = [qy_min, qy_max]
sig1_list.append(sigma_1)
sig2_list.append(sigma_2)
sigr_list.append(sigma_r)
sigma1d_list.append(sigma1d)
# redraw image in global 2d q-space.
self.image_lam = []
total_intensity = 0
sigma_1 = 0
sigma_r = 0
sigma_2 = 0
sigma1d = 0
for ind in range(num_lamda):
lam = lamda_list[ind]
dlam = dlamb_list[ind]
intens = self.setup_tof(lam, dlam)
out = self.get_image(qx_value, qy_value, sig1_list[ind],
sig2_list[ind], sigr_list[ind], qx_min,
qx_max, qy_min, qy_max, coord)
# this is the case of q being outside the detector
#if numpy.all(out==0.0):
# continue
image = out
# set variance as sigmas
sigma_1 += sig1_list[ind] * sig1_list[ind] * self.intensity
sigma_r += sigr_list[ind] * sigr_list[ind] * self.intensity
sigma_2 += sig2_list[ind] * sig2_list[ind] * self.intensity
sigma1d += sigma1d_list[ind] * sigma1d_list[ind] * self.intensity
total_intensity += self.intensity
if total_intensity != 0:
# average variance
image_out = image / total_intensity
sigma_1 = sigma_1 / total_intensity
sigma_r = sigma_r / total_intensity
sigma_2 = sigma_2 / total_intensity
sigma1d = sigma1d / total_intensity
# set sigmas
self.sigma_1 = sqrt(sigma_1)
self.sigma_lamd = sqrt(sigma_r)
self.sigma_2 = sqrt(sigma_2)
self.sigma_1d = sqrt(sigma1d)
# rescale
max_im_val = 1
if max_im_val > 0:
image_out /= max_im_val
else:
image_out = image * 0.0
# Don't calculate sigmas nor set self.sigmas!
sigma_1 = 0
sigma_r = 0
sigma_2 = 0
sigma1d = 0
if len(self.image) > 0:
self.image += image_out
else:
self.image = image_out
# plot image
return self.plot_image(self.image)
def setup_tof(self, wavelength, wavelength_spread):
"""
Setup all parameters in instrument
: param ind: index of lambda, etc
"""
# set wave.wavelength
self.set_wavelength(wavelength)
self.set_wavelength_spread(wavelength_spread)
self.intensity = self.wave.get_intensity()
if wavelength == 0:
msg = "Can't compute the resolution: the wavelength is zero..."
raise RuntimeError, msg
return self.intensity
def compute(self,
wavelength,
wavelength_spread,
qx_value,
qy_value,
coord='cartesian',
tof=False):
"""
Compute the Q resoltuion in || and + direction of 2D
: qx_value: x component of q
: qy_value: y component of q
"""
coord = 'cartesian'
lamb = wavelength
lamb_spread = wavelength_spread
# the shape of wavelength distribution
if tof:
# rectangular
tof_factor = 2
else:
# triangular
tof_factor = 1
# Find polar values
qr_value, phi = self._get_polar_value(qx_value, qy_value)
# vacuum wave transfer
knot = 2 * pi / lamb
# scattering angle theta; always true for plane detector
# aligned vertically to the ko direction
if qr_value > knot:
theta = pi / 2
else:
theta = math.asin(qr_value / knot)
# source aperture size
rone = self.source_aperture_size
# sample aperture size
rtwo = self.sample_aperture_size
# detector pixel size
rthree = self.detector_pix_size
# source to sample(aperture) distance
l_ssa = self.source2sample_distance[0]
# sample(aperture) to detector distance
l_sad = self.sample2detector_distance[0]
# sample (aperture) to sample distance
l_sas = self.sample2sample_distance[0]
# source to sample distance
l_one = l_ssa + l_sas
# sample to detector distance
l_two = l_sad - l_sas
# Sample offset correction for l_one and Lp on variance calculation
l1_cor = (l_ssa * l_two) / (l_sas + l_two)
lp_cor = (l_ssa * l_two) / (l_one + l_two)
# the radial distance to the pixel from the center of the detector
radius = math.tan(theta) * l_two
#Lp = l_one*l_two/(l_one+l_two)
# default polar coordinate
comp1 = 'radial'
comp2 = 'phi'
# in the case of the cartesian coordinate
if coord == 'cartesian':
comp1 = 'x'
comp2 = 'y'
# sigma in the radial/x direction
# for source aperture
sigma_1 = self.get_variance(rone, l1_cor, phi, comp1)
# for sample apperture
sigma_1 += self.get_variance(rtwo, lp_cor, phi, comp1)
# for detector pix
sigma_1 += self.get_variance(rthree, l_two, phi, comp1)
# for gravity term for 1d
sigma_1grav1d = self.get_variance_gravity(
l_ssa, l_sad, lamb, lamb_spread, phi, comp1, 'on') / tof_factor
# for wavelength spread
# reserve for 1d calculation
A_value = self._cal_A_value(lamb, l_ssa, l_sad)
sigma_wave_1, sigma_wave_1_1d = self.get_variance_wave(
A_value, radius, l_two, lamb_spread, phi, 'radial', 'on')
sigma_wave_1 /= tof_factor
sigma_wave_1_1d /= tof_factor
# for 1d
variance_1d_1 = (sigma_1 + sigma_1grav1d) / 2 + sigma_wave_1_1d
# normalize
variance_1d_1 = knot * knot * variance_1d_1 / 12
# for 2d
#sigma_1 += sigma_wave_1
# normalize
sigma_1 = knot * sqrt(sigma_1 / 12)
sigma_r = knot * sqrt(sigma_wave_1 / (tof_factor * 12))
# sigma in the phi/y direction
# for source apperture
sigma_2 = self.get_variance(rone, l1_cor, phi, comp2)
# for sample apperture
sigma_2 += self.get_variance(rtwo, lp_cor, phi, comp2)
# for detector pix
sigma_2 += self.get_variance(rthree, l_two, phi, comp2)
# for gravity term for 1d
sigma_2grav1d = self.get_variance_gravity(
l_ssa, l_sad, lamb, lamb_spread, phi, comp2, 'on') / tof_factor
# for wavelength spread
# reserve for 1d calculation
sigma_wave_2, sigma_wave_2_1d = self.get_variance_wave(
A_value, radius, l_two, lamb_spread, phi, 'phi', 'on')
sigma_wave_2 /= tof_factor
sigma_wave_2_1d /= tof_factor
# for 1d
variance_1d_2 = (sigma_2 + sigma_2grav1d) / 2 + sigma_wave_2_1d
# normalize
variance_1d_2 = knot * knot * variance_1d_2 / 12
# for 2d
#sigma_2 = knot*sqrt(sigma_2/12)
#sigma_2 += sigma_wave_2
# normalize
sigma_2 = knot * sqrt(sigma_2 / 12)
sigma1d = sqrt(variance_1d_1 + variance_1d_2)
# set sigmas
self.sigma_1 = sigma_1
self.sigma_lamd = sigma_r
self.sigma_2 = sigma_2
self.sigma_1d = sigma1d
return qr_value, phi, sigma_1, sigma_2, sigma_r, sigma1d
def _within_detector_range(self, qx_value, qy_value):
"""
check if qvalues are within detector range
"""
# detector range
detector_qx_min = self.detector_qx_min
detector_qx_max = self.detector_qx_max
detector_qy_min = self.detector_qy_min
detector_qy_max = self.detector_qy_max
if self.qxmin_limit > detector_qx_min:
self.qxmin_limit = detector_qx_min
if self.qxmax_limit < detector_qx_max:
self.qxmax_limit = detector_qx_max
if self.qymin_limit > detector_qy_min:
self.qymin_limit = detector_qy_min
if self.qymax_limit < detector_qy_max:
self.qymax_limit = detector_qy_max
if qx_value < detector_qx_min or qx_value > detector_qx_max:
return False
if qy_value < detector_qy_min or qy_value > detector_qy_max:
return False
return True
def get_image(self,
qx_value,
qy_value,
sigma_1,
sigma_2,
sigma_r,
qx_min,
qx_max,
qy_min,
qy_max,
coord='cartesian',
full_cal=True):
"""
Get the resolution in polar coordinate ready to plot
: qx_value: qx_value value
: qy_value: qy_value value
: sigma_1: variance in r direction
: sigma_2: variance in phi direction
: coord: coordinate system of image, 'polar' or 'cartesian'
"""
# Get qx_max and qy_max...
self._get_detector_qxqy_pixels()
qr_value, phi = self._get_polar_value(qx_value, qy_value)
# Check whether the q value is within the detector range
if qx_min < self.qx_min:
self.qx_min = qx_min
#raise ValueError, msg
if qx_max > self.qx_max:
self.qx_max = qx_max
#raise ValueError, msg
if qy_min < self.qy_min:
self.qy_min = qy_min
#raise ValueError, msg
if qy_max > self.qy_max:
self.qy_max = qy_max
#raise ValueError, msg
if not full_cal:
return None
# Make an empty graph in the detector scale
dx_size = (self.qx_max - self.qx_min) / (1000 - 1)
dy_size = (self.qy_max - self.qy_min) / (1000 - 1)
x_val = numpy.arange(self.qx_min, self.qx_max, dx_size)
y_val = numpy.arange(self.qy_max, self.qy_min, -dy_size)
q_1, q_2 = numpy.meshgrid(x_val, y_val)
#q_phi = numpy.arctan(q_1,q_2)
# check whether polar or cartesian
if coord == 'polar':
# Find polar values
qr_value, phi = self._get_polar_value(qx_value, qy_value)
q_1, q_2 = self._rotate_z(q_1, q_2, phi)
qc_1 = qr_value
qc_2 = 0.0
# Calculate the 2D Gaussian distribution image
image = self._gaussian2d_polar(q_1, q_2, qc_1, qc_2, sigma_1,
sigma_2, sigma_r)
else:
# catesian coordinate
# qx_center
qc_1 = qx_value
# qy_center
qc_2 = qy_value
# Calculate the 2D Gaussian distribution image
image = self._gaussian2d(q_1, q_2, qc_1, qc_2, sigma_1, sigma_2,
sigma_r)
# out side of detector
if not self._within_detector_range(qx_value, qy_value):
image *= 0.0
self.intensity = 0.0
#return self.image
# Add it if there are more than one inputs.
if len(self.image_lam) > 0:
self.image_lam += image * self.intensity
else:
self.image_lam = image * self.intensity
return self.image_lam
def plot_image(self, image):
"""
Plot image using pyplot
: image: 2d resolution image
: return plt: pylab object
"""
import matplotlib.pyplot as plt
self.plot = plt
plt.xlabel('$\\rm{Q}_{x} [A^{-1}]$')
plt.ylabel('$\\rm{Q}_{y} [A^{-1}]$')
# Max value of the image
# max = numpy.max(image)
qx_min, qx_max, qy_min, qy_max = self.get_detector_qrange()
# Image
im = plt.imshow(image, extent=[qx_min, qx_max, qy_min, qy_max])
# bilinear interpolation to make it smoother
im.set_interpolation('bilinear')
return plt
def reset_image(self):
"""
Reset image to default (=[])
"""
self.image = []
def get_variance(self, size=[], distance=0, phi=0, comp='radial'):
"""
Get the variance when the slit/pinhole size is given
: size: list that can be one(diameter for circular) or two components(lengths for rectangular)
: distance: [z, x] where z along the incident beam, x // qx_value
: comp: direction of the sigma; can be 'phi', 'y', 'x', and 'radial'
: return variance: sigma^2
"""
# check the length of size (list)
len_size = len(size)
# define sigma component direction
if comp == 'radial':
phi_x = math.cos(phi)
phi_y = math.sin(phi)
elif comp == 'phi':
phi_x = math.sin(phi)
phi_y = math.cos(phi)
elif comp == 'x':
phi_x = 1
phi_y = 0
elif comp == 'y':
phi_x = 0
phi_y = 1
else:
phi_x = 0
phi_y = 0
# calculate each component
# for pinhole w/ radius = size[0]/2
if len_size == 1:
x_comp = (0.5 * size[0]) * sqrt(3)
y_comp = 0
# for rectangular slit
elif len_size == 2:
x_comp = size[0] * phi_x
y_comp = size[1] * phi_y
# otherwise
else:
raise ValueError, " Improper input..."
# get them squared
sigma = x_comp * x_comp
sigma += y_comp * y_comp
# normalize by distance
sigma /= (distance * distance)
return sigma
def get_variance_wave(self,
A_value,
radius,
distance,
spread,
phi,
comp='radial',
switch='on'):
"""
Get the variance when the wavelength spread is given
: radius: the radial distance from the beam center to the pix of q
: distance: sample to detector distance
: spread: wavelength spread (ratio)
: comp: direction of the sigma; can be 'phi', 'y', 'x', and 'radial'
: return variance: sigma^2 for 2d, sigma^2 for 1d [tuple]
"""
if switch.lower() == 'off':
return 0, 0
# check the singular point
if distance == 0 or comp == 'phi':
return 0, 0
else:
# calculate sigma^2 for 1d
sigma1d = 2 * math.pow(radius / distance * spread, 2)
if comp == 'x':
sigma1d *= (math.cos(phi) * math.cos(phi))
elif comp == 'y':
sigma1d *= (math.sin(phi) * math.sin(phi))
else:
sigma1d *= 1
# sigma^2 for 2d
# shift the coordinate due to the gravitational shift
rad_x = radius * math.cos(phi)
rad_y = A_value - radius * math.sin(phi)
radius = math.sqrt(rad_x * rad_x + rad_y * rad_y)
# new phi
phi = math.atan2(-rad_y, rad_x)
self.gravity_phi = phi
# calculate sigma^2
sigma = 2 * math.pow(radius / distance * spread, 2)
if comp == 'x':
sigma *= (math.cos(phi) * math.cos(phi))
elif comp == 'y':
sigma *= (math.sin(phi) * math.sin(phi))
else:
sigma *= 1
return sigma, sigma1d
def get_variance_gravity(self,
s_distance,
d_distance,
wavelength,
spread,
phi,
comp='radial',
switch='on'):
"""
Get the variance from gravity when the wavelength spread is given
: s_distance: source to sample distance
: d_distance: sample to detector distance
: wavelength: wavelength
: spread: wavelength spread (ratio)
: comp: direction of the sigma; can be 'phi', 'y', 'x', and 'radial'
: return variance: sigma^2
"""
if switch.lower() == 'off':
return 0
if self.mass == 0.0:
return 0
# check the singular point
if d_distance == 0 or comp == 'x':
return 0
else:
a_value = self._cal_A_value(None, s_distance, d_distance)
# calculate sigma^2
sigma = math.pow(a_value / d_distance, 2)
sigma *= math.pow(wavelength, 4)
sigma *= math.pow(spread, 2)
sigma *= 8
return sigma
def _cal_A_value(self, lamda, s_distance, d_distance):
"""
Calculate A value for gravity
: s_distance: source to sample distance
: d_distance: sample to detector distance
"""
# neutron mass in cgs unit
self.mass = self.get_neutron_mass()
# plank constant in cgs unit
h_constant = _PLANK_H
# gravity in cgs unit
gravy = _GRAVITY
# m/h
m_over_h = self.mass / h_constant
# A value
a_value = d_distance * (s_distance + d_distance)
a_value *= math.pow(m_over_h / 2, 2)
a_value *= gravy
# unit correction (1/cm to 1/A) for A and d_distance below
a_value *= 1.0E-16
# if lamda is give (broad meanning of A) return 2* lamda^2 * A
if lamda != None:
a_value *= (4 * lamda * lamda)
return a_value
def get_intensity(self):
"""
Get intensity
"""
return self.wave.intensity
def get_wavelength(self):
"""
Get wavelength
"""
return self.wave.wavelength
def get_default_spectrum(self):
"""
Get default_spectrum
"""
return self.wave.get_default_spectrum()
def get_spectrum(self):
"""
Get _spectrum
"""
return self.wave.get_spectrum()
def get_wavelength_spread(self):
"""
Get wavelength spread
"""
return self.wave.wavelength_spread
def get_neutron_mass(self):
"""
Get Neutron mass
"""
return self.wave.mass
def get_source_aperture_size(self):
"""
Get source aperture size
"""
return self.aperture.source_size
def get_sample_aperture_size(self):
"""
Get sample aperture size
"""
return self.aperture.sample_size
def get_detector_pix_size(self):
"""
Get detector pixel size
"""
return self.detector.pix_size
def get_detector_size(self):
"""
Get detector size
"""
return self.detector.size
def get_source2sample_distance(self):
"""
Get detector source2sample_distance
"""
return self.aperture.sample_distance
def get_sample2sample_distance(self):
"""
Get detector sampleslitsample_distance
"""
return self.sample.distance
def get_sample2detector_distance(self):
"""
Get detector sample2detector_distance
"""
return self.detector.distance
def set_intensity(self, intensity):
"""
Set intensity
"""
self.wave.set_intensity(intensity)
def set_wave(self, wavelength):
"""
Set wavelength list or wavelength
"""
if wavelength.__class__.__name__ == 'list':
self.wave.set_wave_list(wavelength)
elif wavelength.__class__.__name__ == 'float':
self.wave.set_wave_list([wavelength])
#self.set_wavelength(wavelength)
else:
raise
def set_wave_spread(self, wavelength_spread):
"""
Set wavelength spread or wavelength spread
"""
if wavelength_spread.__class__.__name__ == 'list':
self.wave.set_wave_spread_list(wavelength_spread)
elif wavelength_spread.__class__.__name__ == 'float':
self.wave.set_wave_spread_list([wavelength_spread])
else:
raise
def set_wavelength(self, wavelength):
"""
Set wavelength
"""
self.wavelength = wavelength
self.wave.set_wavelength(wavelength)
def set_spectrum(self, spectrum):
"""
Set spectrum
"""
self.spectrum = spectrum
self.wave.set_spectrum(spectrum)
def set_wavelength_spread(self, wavelength_spread):
"""
Set wavelength spread
"""
self.wavelength_spread = wavelength_spread
self.wave.set_wavelength_spread(wavelength_spread)
def set_wave_list(self, wavelength_list, wavelengthspread_list):
"""
Set wavelength and its spread list
"""
self.wave.set_wave_list(wavelength_list)
self.wave.set_wave_spread_list(wavelengthspread_list)
def get_wave_list(self):
"""
Set wavelength spread
"""
return self.wave.get_wave_list()
def get_intensity_list(self):
"""
Set wavelength spread
"""
return self.wave.get_intensity_list()
def set_source_aperture_size(self, size):
"""
Set source aperture size
: param size: [dia_value] or [x_value, y_value]
"""
if len(size) < 1 or len(size) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.aperture.set_source_size(size)
def set_neutron_mass(self, mass):
"""
Set Neutron mass
"""
self.wave.set_mass(mass)
self.mass = mass
def set_sample_aperture_size(self, size):
"""
Set sample aperture size
: param size: [dia_value] or [xheight_value, yheight_value]
"""
if len(size) < 1 or len(size) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.aperture.set_sample_size(size)
def set_detector_pix_size(self, size):
"""
Set detector pixel size
"""
self.detector.set_pix_size(size)
def set_detector_size(self, size):
"""
Set detector size in number of pixels
: param size: [pixel_nums] or [x_pix_num, yx_pix_num]
"""
self.detector.set_size(size)
def set_source2sample_distance(self, distance):
"""
Set detector source2sample_distance
: param distance: [distance, x_offset]
"""
if len(distance) < 1 or len(distance) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.aperture.set_sample_distance(distance)
def set_sample2sample_distance(self, distance):
"""
Set detector sample_slit2sample_distance
: param distance: [distance, x_offset]
"""
if len(distance) < 1 or len(distance) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.sample.set_distance(distance)
def set_sample2detector_distance(self, distance):
"""
Set detector sample2detector_distance
: param distance: [distance, x_offset]
"""
if len(distance) < 1 or len(distance) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.detector.set_distance(distance)
def get_all_instrument_params(self):
"""
Get all instrumental parameters
"""
self.mass = self.get_neutron_mass()
self.spectrum = self.get_spectrum()
self.source_aperture_size = self.get_source_aperture_size()
self.sample_aperture_size = self.get_sample_aperture_size()
self.detector_pix_size = self.get_detector_pix_size()
self.detector_size = self.get_detector_size()
self.source2sample_distance = self.get_source2sample_distance()
self.sample2sample_distance = self.get_sample2sample_distance()
self.sample2detector_distance = self.get_sample2detector_distance()
def get_detector_qrange(self):
"""
get max detector q ranges
: return: qx_min, qx_max, qy_min, qy_max tuple
"""
if len(self.qxrange) != 2 or len(self.qyrange) != 2:
return None
qx_min = self.qxrange[0]
qx_max = self.qxrange[1]
qy_min = self.qyrange[0]
qy_max = self.qyrange[1]
return qx_min, qx_max, qy_min, qy_max
def _rotate_z(self, x_value, y_value, theta=0.0):
"""
Rotate x-y cordinate around z-axis by theta
: x_value: numpy array of x values
: y_value: numpy array of y values
: theta: angle to rotate by in rad
:return: x_prime, y-prime
"""
# rotate by theta
x_prime = x_value * math.cos(theta) + y_value * math.sin(theta)
y_prime = -x_value * math.sin(theta) + y_value * math.cos(theta)
return x_prime, y_prime
def _gaussian2d(self, x_val, y_val, x0_val, y0_val, sigma_x, sigma_y,
sigma_r):
"""
Calculate 2D Gaussian distribution
: x_val: x value
: y_val: y value
: x0_val: mean value in x-axis
: y0_val: mean value in y-axis
: sigma_x: variance in x-direction
: sigma_y: variance in y-direction
: return: gaussian (value)
"""
# phi values at each points (not at the center)
x_value = x_val - x0_val
y_value = y_val - y0_val
phi_i = numpy.arctan2(y_val, x_val)
# phi correction due to the gravity shift (in phi)
phi_0 = math.atan2(y0_val, x0_val)
phi_i = phi_i - phi_0 + self.gravity_phi
sin_phi = numpy.sin(self.gravity_phi)
cos_phi = numpy.cos(self.gravity_phi)
x_p = x_value * cos_phi + y_value * sin_phi
y_p = -x_value * sin_phi + y_value * cos_phi
new_sig_x = sqrt(sigma_r * sigma_r / (sigma_x * sigma_x) + 1)
new_sig_y = sqrt(sigma_r * sigma_r / (sigma_y * sigma_y) + 1)
new_x = x_p * cos_phi / new_sig_x - y_p * sin_phi
new_x /= sigma_x
new_y = x_p * sin_phi / new_sig_y + y_p * cos_phi
new_y /= sigma_y
nu_value = -0.5 * (new_x * new_x + new_y * new_y)
gaussian = numpy.exp(nu_value)
# normalizing factor correction
gaussian /= gaussian.sum()
return gaussian
def _gaussian2d_polar(self, x_val, y_val, x0_val, y0_val, sigma_x, sigma_y,
sigma_r):
"""
Calculate 2D Gaussian distribution for polar coodinate
: x_val: x value
: y_val: y value
: x0_val: mean value in x-axis
: y0_val: mean value in y-axis
: sigma_x: variance in r-direction
: sigma_y: variance in phi-direction
: sigma_r: wavelength variance in r-direction
: return: gaussian (value)
"""
sigma_x = sqrt(sigma_x * sigma_x + sigma_r * sigma_r)
# call gaussian1d
gaussian = self._gaussian1d(x_val, x0_val, sigma_x)
gaussian *= self._gaussian1d(y_val, y0_val, sigma_y)
# normalizing factor correction
if sigma_x != 0 and sigma_y != 0:
gaussian *= sqrt(2 * pi)
return gaussian
def _gaussian1d(self, value, mean, sigma):
"""
Calculate 1D Gaussian distribution
: value: value
: mean: mean value
: sigma: variance
: return: gaussian (value)
"""
# default
gaussian = 1.0
if sigma != 0:
# get exponent
nu_value = (value - mean) / sigma
nu_value *= nu_value
nu_value *= -0.5
gaussian *= numpy.exp(nu_value)
gaussian /= sigma
# normalize
gaussian /= sqrt(2 * pi)
return gaussian
def _atan_phi(self, qy_value, qx_value):
"""
Find the angle phi of q on the detector plane for qx_value, qy_value given
: qx_value: x component of q
: qy_value: y component of q
: return phi: the azimuthal angle of q on x-y plane
"""
phi = math.atan2(qy_value, qx_value)
return phi
def _get_detector_qxqy_pixels(self):
"""
Get the pixel positions of the detector in the qx_value-qy_value space
"""
# update all param values
self.get_all_instrument_params()
# wavelength
wavelength = self.wave.wavelength
# Gavity correction
delta_y = self._get_beamcenter_drop() # in cm
# detector_pix size
detector_pix_size = self.detector_pix_size
# Square or circular pixel
if len(detector_pix_size) == 1:
pix_x_size = detector_pix_size[0]
pix_y_size = detector_pix_size[0]
# rectangular pixel pixel
elif len(detector_pix_size) == 2:
pix_x_size = detector_pix_size[0]
pix_y_size = detector_pix_size[1]
else:
raise ValueError, " Input value format error..."
# Sample to detector distance = sample slit to detector
# minus sample offset
sample2detector_distance = self.sample2detector_distance[0] - \
self.sample2sample_distance[0]
# detector offset in x-direction
detector_offset = 0
try:
detector_offset = self.sample2detector_distance[1]
except:
logging.error(sys.exc_value)
# detector size in [no of pix_x,no of pix_y]
detector_pix_nums_x = self.detector_size[0]
# get pix_y if it exists, otherwse take it from [0]
try:
detector_pix_nums_y = self.detector_size[1]
except:
detector_pix_nums_y = self.detector_size[0]
# detector offset in pix number
offset_x = detector_offset / pix_x_size
offset_y = delta_y / pix_y_size
# beam center position in pix number (start from 0)
center_x, center_y = self._get_beamcenter_position(
detector_pix_nums_x, detector_pix_nums_y, offset_x, offset_y)
# distance [cm] from the beam center on detector plane
detector_ind_x = numpy.arange(detector_pix_nums_x)
detector_ind_y = numpy.arange(detector_pix_nums_y)
# shif 0.5 pixel so that pix position is at the center of the pixel
detector_ind_x = detector_ind_x + 0.5
detector_ind_y = detector_ind_y + 0.5
# the relative postion from the beam center
detector_ind_x = detector_ind_x - center_x
detector_ind_y = detector_ind_y - center_y
# unit correction in cm
detector_ind_x = detector_ind_x * pix_x_size
detector_ind_y = detector_ind_y * pix_y_size
qx_value = numpy.zeros(len(detector_ind_x))
qy_value = numpy.zeros(len(detector_ind_y))
i = 0
for indx in detector_ind_x:
qx_value[i] = self._get_qx(indx, sample2detector_distance,
wavelength)
i += 1
i = 0
for indy in detector_ind_y:
qy_value[i] = self._get_qx(indy, sample2detector_distance,
wavelength)
i += 1
# qx_value and qy_value values in array
qx_value = qx_value.repeat(detector_pix_nums_y)
qx_value = qx_value.reshape(detector_pix_nums_x, detector_pix_nums_y)
qy_value = qy_value.repeat(detector_pix_nums_x)
qy_value = qy_value.reshape(detector_pix_nums_y, detector_pix_nums_x)
qy_value = qy_value.transpose()
# p min and max values among the center of pixels
self.qx_min = numpy.min(qx_value)
self.qx_max = numpy.max(qx_value)
self.qy_min = numpy.min(qy_value)
self.qy_max = numpy.max(qy_value)
# Appr. min and max values of the detector display limits
# i.e., edges of the last pixels.
self.qy_min += self._get_qx(-0.5 * pix_y_size,
sample2detector_distance, wavelength)
self.qy_max += self._get_qx(0.5 * pix_y_size, sample2detector_distance,
wavelength)
#if self.qx_min == self.qx_max:
self.qx_min += self._get_qx(-0.5 * pix_x_size,
sample2detector_distance, wavelength)
self.qx_max += self._get_qx(0.5 * pix_x_size, sample2detector_distance,
wavelength)
# min and max values of detecter
self.detector_qx_min = self.qx_min
self.detector_qx_max = self.qx_max
self.detector_qy_min = self.qy_min
self.detector_qy_max = self.qy_max
# try to set it as a Data2D otherwise pass (not required for now)
try:
from sas.sascalc.dataloader.data_info import Data2D
output = Data2D()
inten = numpy.zeros_like(qx_value)
output.data = inten
output.qx_data = qx_value
output.qy_data = qy_value
except:
logging.error(sys.exc_value)
return output
def _get_qx(self, dx_size, det_dist, wavelength):
"""
:param dx_size: x-distance from beam center [cm]
:param det_dist: sample to detector distance [cm]
:return: q-value at the given position
"""
# Distance from beam center in the plane of detector
plane_dist = dx_size
# full scattering angle on the x-axis
theta = numpy.arctan(plane_dist / det_dist)
qx_value = (2.0 * pi / wavelength) * numpy.sin(theta)
return qx_value
def _get_polar_value(self, qx_value, qy_value):
"""
Find qr_value and phi from qx_value and qy_value values
: return qr_value, phi
"""
# find |q| on detector plane
qr_value = sqrt(qx_value * qx_value + qy_value * qy_value)
# find angle phi
phi = self._atan_phi(qy_value, qx_value)
return qr_value, phi
def _get_beamcenter_position(self, num_x, num_y, offset_x, offset_y):
"""
:param num_x: number of pixel in x-direction
:param num_y: number of pixel in y-direction
:param offset: detector offset in x-direction in pix number
:return: pix number; pos_x, pos_y in pix index
"""
# beam center position
pos_x = num_x / 2
pos_y = num_y / 2
# correction for offset
pos_x += offset_x
# correction for gravity that is always negative
pos_y -= offset_y
return pos_x, pos_y
def _get_beamcenter_drop(self):
"""
Get the beam center drop (delta y) in y diection due to gravity
:return delta y: the beam center drop in cm
"""
# Check if mass == 0 (X-ray).
if self.mass == 0:
return 0
# Covert unit from A to cm
unit_cm = 1e-08
# Velocity of neutron in horizontal direction (~ actual velocity)
velocity = _PLANK_H / (self.mass * self.wave.wavelength * unit_cm)
# Compute delta y
delta_y = 0.5
delta_y *= _GRAVITY
sampletodetector = self.sample2detector_distance[0] - \
self.sample2sample_distance[0]
delta_y *= sampletodetector
delta_y *= (self.source2sample_distance[0] +
self.sample2detector_distance[0])
delta_y /= (velocity * velocity)
return delta_y
class ResolutionCalculator(object):
"""
compute resolution in 2D
"""
def __init__(self):
# wavelength
self.wave = Neutron()
# sample
self.sample = Sample()
# aperture
self.aperture = Aperture()
# detector
self.detector = Detector()
# 2d image of the resolution
self.image = []
self.image_lam = []
# resolutions
# lamda in r-direction
self.sigma_lamd = 0
# x-dir (no lamda)
self.sigma_1 = 0
#y-dir (no lamda)
self.sigma_2 = 0
# 1D total
self.sigma_1d = 0
self.gravity_phi = None
# q min and max
self.qx_min = -0.3
self.qx_max = 0.3
self.qy_min = -0.3
self.qy_max = 0.3
# q min and max of the detector
self.detector_qx_min = -0.3
self.detector_qx_max = 0.3
self.detector_qy_min = -0.3
self.detector_qy_max = 0.3
# possible max qrange
self.qxmin_limit = 0
self.qxmax_limit = 0
self.qymin_limit = 0
self.qymax_limit = 0
# plots
self.plot = None
# instrumental params defaults
self.mass = 0
self.intensity = 0
self.wavelength = 0
self.wavelength_spread = 0
self.source_aperture_size = []
self.source2sample_distance = []
self.sample2sample_distance = []
self.sample_aperture_size = []
self.sample2detector_distance = []
self.detector_pix_size = []
self.detector_size = []
self.get_all_instrument_params()
# max q range for all lambdas
self.qxrange = []
self.qyrange = []
def compute_and_plot(self, qx_value, qy_value, qx_min, qx_max,
qy_min, qy_max, coord='cartesian'):
"""
Compute the resolution
: qx_value: x component of q
: qy_value: y component of q
"""
# make sure to update all the variables need.
# except lambda, dlambda, and intensity
self.get_all_instrument_params()
# wavelength etc.
lamda_list, dlamb_list = self.get_wave_list()
intens_list = []
sig1_list = []
sig2_list = []
sigr_list = []
sigma1d_list = []
num_lamda = len(lamda_list)
for num in range(num_lamda):
lam = lamda_list[num]
# wavelength spread
dlam = dlamb_list[num]
intens = self.setup_tof(lam, dlam)
intens_list.append(intens)
# cehck if tof
if num_lamda > 1:
tof = True
else:
tof = False
# compute 2d resolution
_, _, sigma_1, sigma_2, sigma_r, sigma1d = \
self.compute(lam, dlam, qx_value, qy_value, coord, tof)
# make image
image = self.get_image(qx_value, qy_value, sigma_1, sigma_2,
sigma_r, qx_min, qx_max, qy_min, qy_max,
coord, False)
if qx_min > self.qx_min:
qx_min = self.qx_min
if qx_max < self.qx_max:
qx_max = self.qx_max
if qy_min > self.qy_min:
qy_min = self.qy_min
if qy_max < self.qy_max:
qy_max = self.qy_max
# set max qranges
self.qxrange = [qx_min, qx_max]
self.qyrange = [qy_min, qy_max]
sig1_list.append(sigma_1)
sig2_list.append(sigma_2)
sigr_list.append(sigma_r)
sigma1d_list.append(sigma1d)
# redraw image in global 2d q-space.
self.image_lam = []
total_intensity = 0
sigma_1 = 0
sigma_r = 0
sigma_2 = 0
sigma1d = 0
for ind in range(num_lamda):
lam = lamda_list[ind]
dlam = dlamb_list[ind]
intens = self.setup_tof(lam, dlam)
out = self.get_image(qx_value, qy_value, sig1_list[ind],
sig2_list[ind], sigr_list[ind],
qx_min, qx_max, qy_min, qy_max, coord)
# this is the case of q being outside the detector
#if numpy.all(out==0.0):
# continue
image = out
# set variance as sigmas
sigma_1 += sig1_list[ind] * sig1_list[ind] * self.intensity
sigma_r += sigr_list[ind] * sigr_list[ind] * self.intensity
sigma_2 += sig2_list[ind] * sig2_list[ind] * self.intensity
sigma1d += sigma1d_list[ind] * sigma1d_list[ind] * self.intensity
total_intensity += self.intensity
if total_intensity != 0:
# average variance
image_out = image / total_intensity
sigma_1 = sigma_1 / total_intensity
sigma_r = sigma_r / total_intensity
sigma_2 = sigma_2 / total_intensity
sigma1d = sigma1d / total_intensity
# set sigmas
self.sigma_1 = sqrt(sigma_1)
self.sigma_lamd = sqrt(sigma_r)
self.sigma_2 = sqrt(sigma_2)
self.sigma_1d = sqrt(sigma1d)
# rescale
max_im_val = 1
if max_im_val > 0:
image_out /= max_im_val
else:
image_out = image * 0.0
# Don't calculate sigmas nor set self.sigmas!
sigma_1 = 0
sigma_r = 0
sigma_2 = 0
sigma1d = 0
if len(self.image) > 0:
self.image += image_out
else:
self.image = image_out
# plot image
return self.plot_image(self.image)
def setup_tof(self, wavelength, wavelength_spread):
"""
Setup all parameters in instrument
: param ind: index of lambda, etc
"""
# set wave.wavelength
self.set_wavelength(wavelength)
self.set_wavelength_spread(wavelength_spread)
self.intensity = self.wave.get_intensity()
if wavelength == 0:
msg = "Can't compute the resolution: the wavelength is zero..."
raise RuntimeError, msg
return self.intensity
def compute(self, wavelength, wavelength_spread, qx_value, qy_value,
coord='cartesian', tof=False):
"""
Compute the Q resoltuion in || and + direction of 2D
: qx_value: x component of q
: qy_value: y component of q
"""
coord = 'cartesian'
lamb = wavelength
lamb_spread = wavelength_spread
# the shape of wavelength distribution
if tof:
# rectangular
tof_factor = 2
else:
# triangular
tof_factor = 1
# Find polar values
qr_value, phi = self._get_polar_value(qx_value, qy_value)
# vacuum wave transfer
knot = 2*pi/lamb
# scattering angle theta; always true for plane detector
# aligned vertically to the ko direction
if qr_value > knot:
theta = pi/2
else:
theta = math.asin(qr_value/knot)
# source aperture size
rone = self.source_aperture_size
# sample aperture size
rtwo = self.sample_aperture_size
# detector pixel size
rthree = self.detector_pix_size
# source to sample(aperture) distance
l_ssa = self.source2sample_distance[0]
# sample(aperture) to detector distance
l_sad = self.sample2detector_distance[0]
# sample (aperture) to sample distance
l_sas = self.sample2sample_distance[0]
# source to sample distance
l_one = l_ssa + l_sas
# sample to detector distance
l_two = l_sad - l_sas
# Sample offset correction for l_one and Lp on variance calculation
l1_cor = (l_ssa * l_two) / (l_sas + l_two)
lp_cor = (l_ssa * l_two) / (l_one + l_two)
# the radial distance to the pixel from the center of the detector
radius = math.tan(theta) * l_two
#Lp = l_one*l_two/(l_one+l_two)
# default polar coordinate
comp1 = 'radial'
comp2 = 'phi'
# in the case of the cartesian coordinate
if coord == 'cartesian':
comp1 = 'x'
comp2 = 'y'
# sigma in the radial/x direction
# for source aperture
sigma_1 = self.get_variance(rone, l1_cor, phi, comp1)
# for sample apperture
sigma_1 += self.get_variance(rtwo, lp_cor, phi, comp1)
# for detector pix
sigma_1 += self.get_variance(rthree, l_two, phi, comp1)
# for gravity term for 1d
sigma_1grav1d = self.get_variance_gravity(l_ssa, l_sad, lamb,
lamb_spread, phi, comp1, 'on') / tof_factor
# for wavelength spread
# reserve for 1d calculation
A_value = self._cal_A_value(lamb, l_ssa, l_sad)
sigma_wave_1, sigma_wave_1_1d = self.get_variance_wave(A_value,
radius, l_two, lamb_spread,
phi, 'radial', 'on')
sigma_wave_1 /= tof_factor
sigma_wave_1_1d /= tof_factor
# for 1d
variance_1d_1 = (sigma_1 + sigma_1grav1d) / 2 + sigma_wave_1_1d
# normalize
variance_1d_1 = knot * knot * variance_1d_1 / 12
# for 2d
#sigma_1 += sigma_wave_1
# normalize
sigma_1 = knot * sqrt(sigma_1 / 12)
sigma_r = knot * sqrt(sigma_wave_1 / (tof_factor *12))
# sigma in the phi/y direction
# for source apperture
sigma_2 = self.get_variance(rone, l1_cor, phi, comp2)
# for sample apperture
sigma_2 += self.get_variance(rtwo, lp_cor, phi, comp2)
# for detector pix
sigma_2 += self.get_variance(rthree, l_two, phi, comp2)
# for gravity term for 1d
sigma_2grav1d = self.get_variance_gravity(l_ssa, l_sad, lamb,
lamb_spread, phi, comp2, 'on') / tof_factor
# for wavelength spread
# reserve for 1d calculation
sigma_wave_2, sigma_wave_2_1d = self.get_variance_wave(A_value,
radius, l_two, lamb_spread,
phi, 'phi', 'on')
sigma_wave_2 /= tof_factor
sigma_wave_2_1d /= tof_factor
# for 1d
variance_1d_2 = (sigma_2 + sigma_2grav1d) / 2 + sigma_wave_2_1d
# normalize
variance_1d_2 = knot * knot * variance_1d_2 / 12
# for 2d
#sigma_2 = knot*sqrt(sigma_2/12)
#sigma_2 += sigma_wave_2
# normalize
sigma_2 = knot * sqrt(sigma_2 / 12)
sigma1d = sqrt(variance_1d_1 + variance_1d_2)
# set sigmas
self.sigma_1 = sigma_1
self.sigma_lamd = sigma_r
self.sigma_2 = sigma_2
self.sigma_1d = sigma1d
return qr_value, phi, sigma_1, sigma_2, sigma_r, sigma1d
def _within_detector_range(self, qx_value, qy_value):
"""
check if qvalues are within detector range
"""
# detector range
detector_qx_min = self.detector_qx_min
detector_qx_max = self.detector_qx_max
detector_qy_min = self.detector_qy_min
detector_qy_max = self.detector_qy_max
if self.qxmin_limit > detector_qx_min:
self.qxmin_limit = detector_qx_min
if self.qxmax_limit < detector_qx_max:
self.qxmax_limit = detector_qx_max
if self.qymin_limit > detector_qy_min:
self.qymin_limit = detector_qy_min
if self.qymax_limit < detector_qy_max:
self.qymax_limit = detector_qy_max
if qx_value < detector_qx_min or qx_value > detector_qx_max:
return False
if qy_value < detector_qy_min or qy_value > detector_qy_max:
return False
return True
def get_image(self, qx_value, qy_value, sigma_1, sigma_2, sigma_r,
qx_min, qx_max, qy_min, qy_max,
coord='cartesian', full_cal=True):
"""
Get the resolution in polar coordinate ready to plot
: qx_value: qx_value value
: qy_value: qy_value value
: sigma_1: variance in r direction
: sigma_2: variance in phi direction
: coord: coordinate system of image, 'polar' or 'cartesian'
"""
# Get qx_max and qy_max...
self._get_detector_qxqy_pixels()
qr_value, phi = self._get_polar_value(qx_value, qy_value)
# Check whether the q value is within the detector range
if qx_min < self.qx_min:
self.qx_min = qx_min
#raise ValueError, msg
if qx_max > self.qx_max:
self.qx_max = qx_max
#raise ValueError, msg
if qy_min < self.qy_min:
self.qy_min = qy_min
#raise ValueError, msg
if qy_max > self.qy_max:
self.qy_max = qy_max
#raise ValueError, msg
if not full_cal:
return None
# Make an empty graph in the detector scale
dx_size = (self.qx_max - self.qx_min) / (1000 - 1)
dy_size = (self.qy_max - self.qy_min) / (1000 - 1)
x_val = np.arange(self.qx_min, self.qx_max, dx_size)
y_val = np.arange(self.qy_max, self.qy_min, -dy_size)
q_1, q_2 = np.meshgrid(x_val, y_val)
#q_phi = numpy.arctan(q_1,q_2)
# check whether polar or cartesian
if coord == 'polar':
# Find polar values
qr_value, phi = self._get_polar_value(qx_value, qy_value)
q_1, q_2 = self._rotate_z(q_1, q_2, phi)
qc_1 = qr_value
qc_2 = 0.0
# Calculate the 2D Gaussian distribution image
image = self._gaussian2d_polar(q_1, q_2, qc_1, qc_2,
sigma_1, sigma_2, sigma_r)
else:
# catesian coordinate
# qx_center
qc_1 = qx_value
# qy_center
qc_2 = qy_value
# Calculate the 2D Gaussian distribution image
image = self._gaussian2d(q_1, q_2, qc_1, qc_2,
sigma_1, sigma_2, sigma_r)
# out side of detector
if not self._within_detector_range(qx_value, qy_value):
image *= 0.0
self.intensity = 0.0
#return self.image
# Add it if there are more than one inputs.
if len(self.image_lam) > 0:
self.image_lam += image * self.intensity
else:
self.image_lam = image * self.intensity
return self.image_lam
def plot_image(self, image):
"""
Plot image using pyplot
: image: 2d resolution image
: return plt: pylab object
"""
import matplotlib.pyplot as plt
self.plot = plt
plt.xlabel('$\\rm{Q}_{x} [A^{-1}]$')
plt.ylabel('$\\rm{Q}_{y} [A^{-1}]$')
# Max value of the image
# max = numpy.max(image)
qx_min, qx_max, qy_min, qy_max = self.get_detector_qrange()
# Image
im = plt.imshow(image,
extent=[qx_min, qx_max, qy_min, qy_max])
# bilinear interpolation to make it smoother
im.set_interpolation('bilinear')
return plt
def reset_image(self):
"""
Reset image to default (=[])
"""
self.image = []
def get_variance(self, size=[], distance=0, phi=0, comp='radial'):
"""
Get the variance when the slit/pinhole size is given
: size: list that can be one(diameter for circular) or two components(lengths for rectangular)
: distance: [z, x] where z along the incident beam, x // qx_value
: comp: direction of the sigma; can be 'phi', 'y', 'x', and 'radial'
: return variance: sigma^2
"""
# check the length of size (list)
len_size = len(size)
# define sigma component direction
if comp == 'radial':
phi_x = math.cos(phi)
phi_y = math.sin(phi)
elif comp == 'phi':
phi_x = math.sin(phi)
phi_y = math.cos(phi)
elif comp == 'x':
phi_x = 1
phi_y = 0
elif comp == 'y':
phi_x = 0
phi_y = 1
else:
phi_x = 0
phi_y = 0
# calculate each component
# for pinhole w/ radius = size[0]/2
if len_size == 1:
x_comp = (0.5 * size[0]) * sqrt(3)
y_comp = 0
# for rectangular slit
elif len_size == 2:
x_comp = size[0] * phi_x
y_comp = size[1] * phi_y
# otherwise
else:
raise ValueError, " Improper input..."
# get them squared
sigma = x_comp * x_comp
sigma += y_comp * y_comp
# normalize by distance
sigma /= (distance * distance)
return sigma
def get_variance_wave(self, A_value, radius, distance, spread, phi,
comp='radial', switch='on'):
"""
Get the variance when the wavelength spread is given
: radius: the radial distance from the beam center to the pix of q
: distance: sample to detector distance
: spread: wavelength spread (ratio)
: comp: direction of the sigma; can be 'phi', 'y', 'x', and 'radial'
: return variance: sigma^2 for 2d, sigma^2 for 1d [tuple]
"""
if switch.lower() == 'off':
return 0, 0
# check the singular point
if distance == 0 or comp == 'phi':
return 0, 0
else:
# calculate sigma^2 for 1d
sigma1d = 2 * math.pow(radius/distance*spread, 2)
if comp == 'x':
sigma1d *= (math.cos(phi)*math.cos(phi))
elif comp == 'y':
sigma1d *= (math.sin(phi)*math.sin(phi))
else:
sigma1d *= 1
# sigma^2 for 2d
# shift the coordinate due to the gravitational shift
rad_x = radius * math.cos(phi)
rad_y = A_value - radius * math.sin(phi)
radius = math.sqrt(rad_x * rad_x + rad_y * rad_y)
# new phi
phi = math.atan2(-rad_y, rad_x)
self.gravity_phi = phi
# calculate sigma^2
sigma = 2 * math.pow(radius/distance*spread, 2)
if comp == 'x':
sigma *= (math.cos(phi)*math.cos(phi))
elif comp == 'y':
sigma *= (math.sin(phi)*math.sin(phi))
else:
sigma *= 1
return sigma, sigma1d
def get_variance_gravity(self, s_distance, d_distance, wavelength, spread,
phi, comp='radial', switch='on'):
"""
Get the variance from gravity when the wavelength spread is given
: s_distance: source to sample distance
: d_distance: sample to detector distance
: wavelength: wavelength
: spread: wavelength spread (ratio)
: comp: direction of the sigma; can be 'phi', 'y', 'x', and 'radial'
: return variance: sigma^2
"""
if switch.lower() == 'off':
return 0
if self.mass == 0.0:
return 0
# check the singular point
if d_distance == 0 or comp == 'x':
return 0
else:
a_value = self._cal_A_value(None, s_distance, d_distance)
# calculate sigma^2
sigma = math.pow(a_value / d_distance, 2)
sigma *= math.pow(wavelength, 4)
sigma *= math.pow(spread, 2)
sigma *= 8
return sigma
def _cal_A_value(self, lamda, s_distance, d_distance):
"""
Calculate A value for gravity
: s_distance: source to sample distance
: d_distance: sample to detector distance
"""
# neutron mass in cgs unit
self.mass = self.get_neutron_mass()
# plank constant in cgs unit
h_constant = _PLANK_H
# gravity in cgs unit
gravy = _GRAVITY
# m/h
m_over_h = self.mass / h_constant
# A value
a_value = d_distance * (s_distance + d_distance)
a_value *= math.pow(m_over_h / 2, 2)
a_value *= gravy
# unit correction (1/cm to 1/A) for A and d_distance below
a_value *= 1.0E-16
# if lamda is give (broad meanning of A) return 2* lamda^2 * A
if lamda is not None:
a_value *= (4 * lamda * lamda)
return a_value
def get_intensity(self):
"""
Get intensity
"""
return self.wave.intensity
def get_wavelength(self):
"""
Get wavelength
"""
return self.wave.wavelength
def get_default_spectrum(self):
"""
Get default_spectrum
"""
return self.wave.get_default_spectrum()
def get_spectrum(self):
"""
Get _spectrum
"""
return self.wave.get_spectrum()
def get_wavelength_spread(self):
"""
Get wavelength spread
"""
return self.wave.wavelength_spread
def get_neutron_mass(self):
"""
Get Neutron mass
"""
return self.wave.mass
def get_source_aperture_size(self):
"""
Get source aperture size
"""
return self.aperture.source_size
def get_sample_aperture_size(self):
"""
Get sample aperture size
"""
return self.aperture.sample_size
def get_detector_pix_size(self):
"""
Get detector pixel size
"""
return self.detector.pix_size
def get_detector_size(self):
"""
Get detector size
"""
return self.detector.size
def get_source2sample_distance(self):
"""
Get detector source2sample_distance
"""
return self.aperture.sample_distance
def get_sample2sample_distance(self):
"""
Get detector sampleslitsample_distance
"""
return self.sample.distance
def get_sample2detector_distance(self):
"""
Get detector sample2detector_distance
"""
return self.detector.distance
def set_intensity(self, intensity):
"""
Set intensity
"""
self.wave.set_intensity(intensity)
def set_wave(self, wavelength):
"""
Set wavelength list or wavelength
"""
if wavelength.__class__.__name__ == 'list':
self.wave.set_wave_list(wavelength)
elif wavelength.__class__.__name__ == 'float':
self.wave.set_wave_list([wavelength])
#self.set_wavelength(wavelength)
else:
raise
def set_wave_spread(self, wavelength_spread):
"""
Set wavelength spread or wavelength spread
"""
if wavelength_spread.__class__.__name__ == 'list':
self.wave.set_wave_spread_list(wavelength_spread)
elif wavelength_spread.__class__.__name__ == 'float':
self.wave.set_wave_spread_list([wavelength_spread])
else:
raise
def set_wavelength(self, wavelength):
"""
Set wavelength
"""
self.wavelength = wavelength
self.wave.set_wavelength(wavelength)
def set_spectrum(self, spectrum):
"""
Set spectrum
"""
self.spectrum = spectrum
self.wave.set_spectrum(spectrum)
def set_wavelength_spread(self, wavelength_spread):
"""
Set wavelength spread
"""
self.wavelength_spread = wavelength_spread
self.wave.set_wavelength_spread(wavelength_spread)
def set_wave_list(self, wavelength_list, wavelengthspread_list):
"""
Set wavelength and its spread list
"""
self.wave.set_wave_list(wavelength_list)
self.wave.set_wave_spread_list(wavelengthspread_list)
def get_wave_list(self):
"""
Set wavelength spread
"""
return self.wave.get_wave_list()
def get_intensity_list(self):
"""
Set wavelength spread
"""
return self.wave.get_intensity_list()
def set_source_aperture_size(self, size):
"""
Set source aperture size
: param size: [dia_value] or [x_value, y_value]
"""
if len(size) < 1 or len(size) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.aperture.set_source_size(size)
def set_neutron_mass(self, mass):
"""
Set Neutron mass
"""
self.wave.set_mass(mass)
self.mass = mass
def set_sample_aperture_size(self, size):
"""
Set sample aperture size
: param size: [dia_value] or [xheight_value, yheight_value]
"""
if len(size) < 1 or len(size) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.aperture.set_sample_size(size)
def set_detector_pix_size(self, size):
"""
Set detector pixel size
"""
self.detector.set_pix_size(size)
def set_detector_size(self, size):
"""
Set detector size in number of pixels
: param size: [pixel_nums] or [x_pix_num, yx_pix_num]
"""
self.detector.set_size(size)
def set_source2sample_distance(self, distance):
"""
Set detector source2sample_distance
: param distance: [distance, x_offset]
"""
if len(distance) < 1 or len(distance) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.aperture.set_sample_distance(distance)
def set_sample2sample_distance(self, distance):
"""
Set detector sample_slit2sample_distance
: param distance: [distance, x_offset]
"""
if len(distance) < 1 or len(distance) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.sample.set_distance(distance)
def set_sample2detector_distance(self, distance):
"""
Set detector sample2detector_distance
: param distance: [distance, x_offset]
"""
if len(distance) < 1 or len(distance) > 2:
raise RuntimeError, "The length of the size must be one or two."
self.detector.set_distance(distance)
def get_all_instrument_params(self):
"""
Get all instrumental parameters
"""
self.mass = self.get_neutron_mass()
self.spectrum = self.get_spectrum()
self.source_aperture_size = self.get_source_aperture_size()
self.sample_aperture_size = self.get_sample_aperture_size()
self.detector_pix_size = self.get_detector_pix_size()
self.detector_size = self.get_detector_size()
self.source2sample_distance = self.get_source2sample_distance()
self.sample2sample_distance = self.get_sample2sample_distance()
self.sample2detector_distance = self.get_sample2detector_distance()
def get_detector_qrange(self):
"""
get max detector q ranges
: return: qx_min, qx_max, qy_min, qy_max tuple
"""
if len(self.qxrange) != 2 or len(self.qyrange) != 2:
return None
qx_min = self.qxrange[0]
qx_max = self.qxrange[1]
qy_min = self.qyrange[0]
qy_max = self.qyrange[1]
return qx_min, qx_max, qy_min, qy_max
def _rotate_z(self, x_value, y_value, theta=0.0):
"""
Rotate x-y cordinate around z-axis by theta
: x_value: numpy array of x values
: y_value: numpy array of y values
: theta: angle to rotate by in rad
:return: x_prime, y-prime
"""
# rotate by theta
x_prime = x_value * math.cos(theta) + y_value * math.sin(theta)
y_prime = -x_value * math.sin(theta) + y_value * math.cos(theta)
return x_prime, y_prime
def _gaussian2d(self, x_val, y_val, x0_val, y0_val,
sigma_x, sigma_y, sigma_r):
"""
Calculate 2D Gaussian distribution
: x_val: x value
: y_val: y value
: x0_val: mean value in x-axis
: y0_val: mean value in y-axis
: sigma_x: variance in x-direction
: sigma_y: variance in y-direction
: return: gaussian (value)
"""
# phi values at each points (not at the center)
x_value = x_val - x0_val
y_value = y_val - y0_val
phi_i = np.arctan2(y_val, x_val)
# phi correction due to the gravity shift (in phi)
phi_0 = math.atan2(y0_val, x0_val)
phi_i = phi_i - phi_0 + self.gravity_phi
sin_phi = np.sin(self.gravity_phi)
cos_phi = np.cos(self.gravity_phi)
x_p = x_value * cos_phi + y_value * sin_phi
y_p = -x_value * sin_phi + y_value * cos_phi
new_sig_x = sqrt(sigma_r * sigma_r / (sigma_x * sigma_x) + 1)
new_sig_y = sqrt(sigma_r * sigma_r / (sigma_y * sigma_y) + 1)
new_x = x_p * cos_phi / new_sig_x - y_p * sin_phi
new_x /= sigma_x
new_y = x_p * sin_phi / new_sig_y + y_p * cos_phi
new_y /= sigma_y
nu_value = -0.5 * (new_x * new_x + new_y * new_y)
gaussian = np.exp(nu_value)
# normalizing factor correction
gaussian /= gaussian.sum()
return gaussian
def _gaussian2d_polar(self, x_val, y_val, x0_val, y0_val,
sigma_x, sigma_y, sigma_r):
"""
Calculate 2D Gaussian distribution for polar coodinate
: x_val: x value
: y_val: y value
: x0_val: mean value in x-axis
: y0_val: mean value in y-axis
: sigma_x: variance in r-direction
: sigma_y: variance in phi-direction
: sigma_r: wavelength variance in r-direction
: return: gaussian (value)
"""
sigma_x = sqrt(sigma_x * sigma_x + sigma_r * sigma_r)
# call gaussian1d
gaussian = self._gaussian1d(x_val, x0_val, sigma_x)
gaussian *= self._gaussian1d(y_val, y0_val, sigma_y)
# normalizing factor correction
if sigma_x != 0 and sigma_y != 0:
gaussian *= sqrt(2 * pi)
return gaussian
def _gaussian1d(self, value, mean, sigma):
"""
Calculate 1D Gaussian distribution
: value: value
: mean: mean value
: sigma: variance
: return: gaussian (value)
"""
# default
gaussian = 1.0
if sigma != 0:
# get exponent
nu_value = (value - mean) / sigma
nu_value *= nu_value
nu_value *= -0.5
gaussian *= np.exp(nu_value)
gaussian /= sigma
# normalize
gaussian /= sqrt(2 * pi)
return gaussian
def _atan_phi(self, qy_value, qx_value):
"""
Find the angle phi of q on the detector plane for qx_value, qy_value given
: qx_value: x component of q
: qy_value: y component of q
: return phi: the azimuthal angle of q on x-y plane
"""
phi = math.atan2(qy_value, qx_value)
return phi
def _get_detector_qxqy_pixels(self):
"""
Get the pixel positions of the detector in the qx_value-qy_value space
"""
# update all param values
self.get_all_instrument_params()
# wavelength
wavelength = self.wave.wavelength
# Gavity correction
delta_y = self._get_beamcenter_drop() # in cm
# detector_pix size
detector_pix_size = self.detector_pix_size
# Square or circular pixel
if len(detector_pix_size) == 1:
pix_x_size = detector_pix_size[0]
pix_y_size = detector_pix_size[0]
# rectangular pixel pixel
elif len(detector_pix_size) == 2:
pix_x_size = detector_pix_size[0]
pix_y_size = detector_pix_size[1]
else:
raise ValueError, " Input value format error..."
# Sample to detector distance = sample slit to detector
# minus sample offset
sample2detector_distance = self.sample2detector_distance[0] - \
self.sample2sample_distance[0]
# detector offset in x-direction
detector_offset = 0
try:
detector_offset = self.sample2detector_distance[1]
except:
logger.error(sys.exc_value)
# detector size in [no of pix_x,no of pix_y]
detector_pix_nums_x = self.detector_size[0]
# get pix_y if it exists, otherwse take it from [0]
try:
detector_pix_nums_y = self.detector_size[1]
except:
detector_pix_nums_y = self.detector_size[0]
# detector offset in pix number
offset_x = detector_offset / pix_x_size
offset_y = delta_y / pix_y_size
# beam center position in pix number (start from 0)
center_x, center_y = self._get_beamcenter_position(detector_pix_nums_x,
detector_pix_nums_y,
offset_x, offset_y)
# distance [cm] from the beam center on detector plane
detector_ind_x = np.arange(detector_pix_nums_x)
detector_ind_y = np.arange(detector_pix_nums_y)
# shif 0.5 pixel so that pix position is at the center of the pixel
detector_ind_x = detector_ind_x + 0.5
detector_ind_y = detector_ind_y + 0.5
# the relative postion from the beam center
detector_ind_x = detector_ind_x - center_x
detector_ind_y = detector_ind_y - center_y
# unit correction in cm
detector_ind_x = detector_ind_x * pix_x_size
detector_ind_y = detector_ind_y * pix_y_size
qx_value = np.zeros(len(detector_ind_x))
qy_value = np.zeros(len(detector_ind_y))
i = 0
for indx in detector_ind_x:
qx_value[i] = self._get_qx(indx, sample2detector_distance, wavelength)
i += 1
i = 0
for indy in detector_ind_y:
qy_value[i] = self._get_qx(indy, sample2detector_distance, wavelength)
i += 1
# qx_value and qy_value values in array
qx_value = qx_value.repeat(detector_pix_nums_y)
qx_value = qx_value.reshape(detector_pix_nums_x, detector_pix_nums_y)
qy_value = qy_value.repeat(detector_pix_nums_x)
qy_value = qy_value.reshape(detector_pix_nums_y, detector_pix_nums_x)
qy_value = qy_value.transpose()
# p min and max values among the center of pixels
self.qx_min = np.min(qx_value)
self.qx_max = np.max(qx_value)
self.qy_min = np.min(qy_value)
self.qy_max = np.max(qy_value)
# Appr. min and max values of the detector display limits
# i.e., edges of the last pixels.
self.qy_min += self._get_qx(-0.5 * pix_y_size,
sample2detector_distance, wavelength)
self.qy_max += self._get_qx(0.5 * pix_y_size,
sample2detector_distance, wavelength)
#if self.qx_min == self.qx_max:
self.qx_min += self._get_qx(-0.5 * pix_x_size,
sample2detector_distance, wavelength)
self.qx_max += self._get_qx(0.5 * pix_x_size,
sample2detector_distance, wavelength)
# min and max values of detecter
self.detector_qx_min = self.qx_min
self.detector_qx_max = self.qx_max
self.detector_qy_min = self.qy_min
self.detector_qy_max = self.qy_max
# try to set it as a Data2D otherwise pass (not required for now)
try:
from sas.sascalc.dataloader.data_info import Data2D
output = Data2D()
inten = np.zeros_like(qx_value)
output.data = inten
output.qx_data = qx_value
output.qy_data = qy_value
except:
logger.error(sys.exc_value)
return output
def _get_qx(self, dx_size, det_dist, wavelength):
"""
:param dx_size: x-distance from beam center [cm]
:param det_dist: sample to detector distance [cm]
:return: q-value at the given position
"""
# Distance from beam center in the plane of detector
plane_dist = dx_size
# full scattering angle on the x-axis
theta = np.arctan(plane_dist / det_dist)
qx_value = (2.0 * pi / wavelength) * np.sin(theta)
return qx_value
def _get_polar_value(self, qx_value, qy_value):
"""
Find qr_value and phi from qx_value and qy_value values
: return qr_value, phi
"""
# find |q| on detector plane
qr_value = sqrt(qx_value*qx_value + qy_value*qy_value)
# find angle phi
phi = self._atan_phi(qy_value, qx_value)
return qr_value, phi
def _get_beamcenter_position(self, num_x, num_y, offset_x, offset_y):
"""
:param num_x: number of pixel in x-direction
:param num_y: number of pixel in y-direction
:param offset: detector offset in x-direction in pix number
:return: pix number; pos_x, pos_y in pix index
"""
# beam center position
pos_x = num_x / 2
pos_y = num_y / 2
# correction for offset
pos_x += offset_x
# correction for gravity that is always negative
pos_y -= offset_y
return pos_x, pos_y
def _get_beamcenter_drop(self):
"""
Get the beam center drop (delta y) in y diection due to gravity
:return delta y: the beam center drop in cm
"""
# Check if mass == 0 (X-ray).
if self.mass == 0:
return 0
# Covert unit from A to cm
unit_cm = 1e-08
# Velocity of neutron in horizontal direction (~ actual velocity)
velocity = _PLANK_H / (self.mass * self.wave.wavelength * unit_cm)
# Compute delta y
delta_y = 0.5
delta_y *= _GRAVITY
sampletodetector = self.sample2detector_distance[0] - \
self.sample2sample_distance[0]
delta_y *= sampletodetector
delta_y *= (self.source2sample_distance[0] + self.sample2detector_distance[0])
delta_y /= (velocity * velocity)
return delta_y