def wavelength_loop(cube, head, wavels, out_cube, newsize, outspax):
'''Function to take input datacube and process it iteratively through
each wavelength channel as follows:
- Generate PSF array for given channel
- Add effect of ADR to channel
- Convolve cube channel with PSF
- Frebin up to chosen output spaxel scale
Inputs:
cube: Datacube
head: Datacube header
wavels: Wavelength array
out_cube: Empty output cube
newsize: tuple containing (x_newsize, y_newsize) array sizes
outspax: output spaxels (x, y) (mas, mas)
Output:
cube: Processed cube
head: Updated header
'''
nspec = wp.NIRSpec()
nspec.pupilopd = None
print 'OPD = ', nspec.pupilopd
oversamp = 1000. / float(outspax[0])
for l in xrange(len(wavels)):
#Print percentage bar
update_progress(n.round(l / float(len(wavels)), 2))
#Create PSF channel
psf = nspec.calcPSF(outfile=None,
source=None,
filter=None,
nlambda=None,
monochromatic=wavels[l] * 1.E-6,
oversample=oversamp,
fov_arcsec=5,
rebin=False)
psf = psf[0].data
#Convolve cube channel with PSF channel
channel = psf_convolve(cube[l, :, :], psf)
#Frebin datacube up to output spaxel scale
newsize = (int(newsize[0]), int(newsize[1]))
channel *= (head['CDELT1'] * head['CDELT2'] * 1.E-6)
channel = frebin(channel, (newsize[0], newsize[1]), total=True)
channel /= (outspax[0] * outspax[1] * 1.E-6)
#Add channel to output cube
out_cube[l, :, :] = channel
return out_cube, head
def sky_background(wavels, delta_lambda, dit):
'''Function that generates a sky background curve combining
sky continuum, sky thermal emission and sky emission lines.
Inputs:
wavels: array of wavelengths for datacube
delta_lambda: resolution element [um]
dit: exposure time [s]. This determins how the sky emission
line amplitudes vary through the exposure.
Outputs:
sky_bg_curve: array of total sky background
[units of photons/s/m^2/um/arcsec^2]
for each wavelength value in wavels
'''
#Load up all datafile using n.genfromtxt(...)
#sky_em = n.genfromtxt(bgpath+'ASM_background/radiance_resolution_0.15_angstroms_MICRONS.txt')
sky_em = n.genfromtxt(
os.path.join(
bgpath,
'ASM_background/radiance_resolution_0.15_angstroms_MICRONS.txt'))
#Cut down data to relevent region.
se_start_arg = n.where(sky_em[:, 0] < wavels[0])[0][-1]
se_end_arg = n.where(sky_em[:, 0] > wavels[-1])[0][0]
sky_em_slice = sky_em[se_start_arg:se_end_arg + 1, :]
if type(delta_lambda) == n.ndarray:
#Low resolution mode. Use low_res_mode function to generate sky emission spectrum
sky_em_spec = low_res_spec(sky_em, delta_lambda, False)
binned_sky_em = sky_em_spec[:, 1].copy()
else:
#Convolve sky transmission array with Gaussian LSF of
#FWHM = sqrt(new_resolution**2-old_resolution**2)
#to fold in spectrum for each spectral pixel.
input_disp = sky_em[1, 0] - sky_em[0, 0]
sigma = n.sqrt(delta_lambda**2 -
input_disp**2) / (2. * n.sqrt(2. * n.log(2.)))
conv_sky_em = gauss_convolve(sky_em_slice,
sigma,
lambda_space='Linear')
###new 30-05-14
conv_sky_em_ph = conv_sky_em[:,
1] * input_disp #convert to units of photons/s/m^2/arcsec^2
binned_sky_em_ph = frebin(
conv_sky_em_ph.reshape(len(conv_sky_em_ph), 1), (1, len(wavels)),
True) #Total photons conserved
binned_sky_em = binned_sky_em_ph / float(
wavels[1] -
wavels[0]) #reconvert back to photons/s/m^2/um/arcsec^2
binned_sky_em.shape = (len(wavels), 1, 1)
return binned_sky_em
def pp_wavelength_channel(chann, head, wave, l, newsize, outspax):
'''Function to take input datacube and process it iteratively through
each wavelength channel as follows:
- Generate PSF array for given channel
- Add effect of ADR to channel
- Convolve cube channel with PSF
- Frebin up to chosen output spaxel scale
Inputs:
chann: cube channel
head: Datacube header
wave: wavelength [um]
l: iteration no.
out_cube: Empty output cube
newsize: tuple containing (x_newsize, y_newsize) array sizes
outspax: tuple containing (x, y) output spaxel scales
Output:
cube: Processed cube
head: Updated header
inspax: Input spaxel scale (mas, mas)
outspax: Output spaxel scale (mas, mas)
'''
nspec = wp.NIRSpec()
nspec.pupilopd = None
#print 'OPD = ', nspec.pupilopd
oversamp = 1000. / float(outspax[0])
#Create PSF channel
#print 'Wavelength = ', wave*1.E-6, 'm'
psf = nspec.calcPSF(outfile=None,
source=None,
filter=None,
nlambda=None,
monochromatic=wave * 1.E-6,
oversample=oversamp,
fov_arcsec=5,
rebin=False)
psf = psf[0].data
#Convolve cube channel with PSF channel
chann = psf_convolve(chann, psf)
#Frebin datacube up to output spaxel scale
newsize = (int(newsize[0]), int(newsize[1]))
chann *= (head['CDELT1'] * head['CDELT2'] * 1.E-6)
chann = frebin(chann, (newsize[0], newsize[1]), total=True)
chann /= (outspax[0] * outspax[1] * 1.E-6)
return chann, l
def wavelength_loop(cube, head, wavels, out_cube, newsize, outspax):
'''Function to take input datacube and process it iteratively through
each wavelength channel as follows:
- Generate PSF array for given channel
- Add effect of ADR to channel
- Convolve cube channel with PSF
- Frebin up to chosen output spaxel scale
Inputs:
cube: Datacube
head: Datacube header
wavels: Wavelength array
out_cube: Empty output cube
newsize: tuple containing (x_newsize, y_newsize) array sizes
outspax: output spaxels (x, y) (mas, mas)
Output:
cube: Processed cube
head: Updated header
'''
nspec = wp.NIRSpec()
nspec.pupilopd = None
print 'OPD = ', nspec.pupilopd
oversamp = 1000./float(outspax[0])
for l in xrange(len(wavels)):
#Print percentage bar
update_progress(n.round(l/float(len(wavels)),2))
#Create PSF channel
psf = nspec.calcPSF(outfile=None, source=None, filter=None, nlambda=None,
monochromatic=wavels[l]*1.E-6, oversample=oversamp,
fov_arcsec=5, rebin=False)
psf = psf[0].data
#Convolve cube channel with PSF channel
channel = psf_convolve(cube[l,:,:], psf)
#Frebin datacube up to output spaxel scale
newsize = (int(newsize[0]), int(newsize[1]))
channel *= (head['CDELT1']*head['CDELT2']*1.E-6)
channel = frebin(channel, (newsize[0],newsize[1]), total=True)
channel /= (outspax[0]*outspax[1]*1.E-6)
#Add channel to output cube
out_cube[l,:,:] = channel
return out_cube, head
def pp_wavelength_channel(chann, head, wave, l, newsize, outspax):
'''Function to take input datacube and process it iteratively through
each wavelength channel as follows:
- Generate PSF array for given channel
- Add effect of ADR to channel
- Convolve cube channel with PSF
- Frebin up to chosen output spaxel scale
Inputs:
chann: cube channel
head: Datacube header
wave: wavelength [um]
l: iteration no.
out_cube: Empty output cube
newsize: tuple containing (x_newsize, y_newsize) array sizes
outspax: tuple containing (x, y) output spaxel scales
Output:
cube: Processed cube
head: Updated header
inspax: Input spaxel scale (mas, mas)
outspax: Output spaxel scale (mas, mas)
'''
nspec = wp.NIRSpec()
nspec.pupilopd = None
#print 'OPD = ', nspec.pupilopd
oversamp = 1000./float(outspax[0])
#Create PSF channel
#print 'Wavelength = ', wave*1.E-6, 'm'
psf = nspec.calcPSF(outfile=None, source=None, filter=None, nlambda=None,
monochromatic=wave*1.E-6, oversample=oversamp,
fov_arcsec=5, rebin=False)
psf = psf[0].data
#Convolve cube channel with PSF channel
chann = psf_convolve(chann, psf)
#Frebin datacube up to output spaxel scale
newsize = (int(newsize[0]), int(newsize[1]))
chann *= (head['CDELT1']*head['CDELT2']*1.E-6)
chann = frebin(chann, (newsize[0],newsize[1]), total=True)
chann /= (outspax[0]*outspax[1]*1.E-6)
return chann, l
def my_convolution(chann, head, newsize, outspax, psf, instpsf):
#Convolve cube channel with PSF channel
chann = psf_convolve(chann, psf)
#Convolve cube channel with instrument PSF
chann = psf_convolve(chann, instpsf)
#Frebin datacube up to output spaxel scale
newsize = (int(newsize[0]), int(newsize[1]))
#chann *= (head['CDELT1']*head['CDELT2']*1.E-6)
chann = frebin(chann, (newsize[0],newsize[1]), total=True)
#chann /= (outspax[0]*outspax[1]*1.E-6)
return chann
def sky_background(wavels, delta_lambda, dit):
'''Function that generates a sky background curve combining
sky continuum, sky thermal emission and sky emission lines.
Inputs:
wavels: array of wavelengths for datacube
delta_lambda: resolution element [um]
dit: exposure time [s]. This determins how the sky emission
line amplitudes vary through the exposure.
Outputs:
sky_bg_curve: array of total sky background
[units of photons/s/m^2/um/arcsec^2]
for each wavelength value in wavels
'''
#Load up all datafile using n.genfromtxt(...)
#sky_em = n.genfromtxt(bgpath+'ASM_background/radiance_resolution_0.15_angstroms_MICRONS.txt')
sky_em = n.genfromtxt(os.path.join(bgpath,'ASM_background/radiance_resolution_0.15_angstroms_MICRONS.txt'))
#Cut down data to relevent region.
se_start_arg = n.where(sky_em[:,0] < wavels[0])[0][-1]
se_end_arg = n.where(sky_em[:,0] > wavels[-1])[0][0]
sky_em_slice = sky_em[se_start_arg:se_end_arg+1,:]
if type(delta_lambda) == n.ndarray:
#Low resolution mode. Use low_res_mode function to generate sky emission spectrum
sky_em_spec = low_res_spec(sky_em, delta_lambda, False)
binned_sky_em = sky_em_spec[:,1].copy()
else:
#Convolve sky transmission array with Gaussian LSF of
#FWHM = sqrt(new_resolution**2-old_resolution**2)
#to fold in spectrum for each spectral pixel.
input_disp = sky_em[1,0] - sky_em[0,0]
sigma = n.sqrt(delta_lambda**2-input_disp**2)/(2.*n.sqrt(2.*n.log(2.)))
conv_sky_em = gauss_convolve(sky_em_slice, sigma, lambda_space='Linear')
###new 30-05-14
conv_sky_em_ph = conv_sky_em[:,1]*input_disp #convert to units of photons/s/m^2/arcsec^2
binned_sky_em_ph = frebin(conv_sky_em_ph.reshape(len(conv_sky_em_ph),1), (1,len(wavels)), True) #Total photons conserved
binned_sky_em = binned_sky_em_ph/float(wavels[1]-wavels[0]) #reconvert back to photons/s/m^2/um/arcsec^2
binned_sky_em.shape = (len(wavels),1,1)
return binned_sky_em
def wavelength_loop(cube,
head,
wavels,
out_cube,
AO,
psfvars,
adrvals,
newsize,
outspax,
adr_switch='ON'):
'''Function to take input datacube and process it iteratively through
each wavelength channel as follows:
- Generate PSF array for given channel
- Add effect of ADR to channel
- Convolve cube channel with PSF
- Frebin up to chosen output spaxel scale
Inputs:
cube: Datacube
head: Datacube header
wavels: Wavelength array
out_cube: Empty output cube
AO: AO mode [LTAO, SCAO, Gaussian]
psdvars: list containing [psfparams, psfspax, psfsize, [D,eps],
res_jitter, seeing, user_psf, user_psflams]
adrvals: array of ADR values
newsize: tuple containing (x_newsize, y_newsize) array sizes
outspax: tuple containing (x, y) output spaxel scales
adr_switch: ON or OFF. Turns ADR effect on or off.
Output:
cube: Processed cube
head: Updated header
inspax: Input spaxel scale (mas, mas)
outspax: Output spaxel scale (mas, mas)
'''
for l in xrange(len(wavels)):
#Print percentage bar
update_progress(n.round(l / float(len(wavels)), 2))
#Create PSF channel
#If user PSF and 2D image
upsf = psfvars[-2]
upsflams = psfvars[-1]
if type(upsf) != str and type(upsflams) == str:
psf = upsf
#If User PSF and 3D cube
elif type(upsf) != str and type(upsflams) != str:
#Interpolate PSF cube
interp = interp1d(upsflams, upsf, axis=0)
psf = interp(wavels[l])
elif AO == 'LTAO' or AO == 'SCAO' or AO == 'GLAO':
psf = create_psf_channel(psfvars[0], l, psfvars[1],
(head['CDELT1'], head['CDELT2']),
psfvars[2], psfvars[3], psfvars[4])
elif AO == 'Gaussian':
psf = create_Gausspsf_channel(wavels[l],
psfvars[5],
psfvars[3],
psfvars[4],
psfvars[2],
Nyquist=False,
psfspax=psfvars[1],
output_spax=(head['CDELT1'],
head['CDELT2']))
else:
print 'AO = ', AO
raise ValueError('AO choice error!')
#Create instrument PSF array
instpsf = create_instpsf(psfvars[2], psfvars[1], outspax,
(head['CDELT1'], head['CDELT2']))
#Add ADR effect to channel
if adr_switch == 'ON':
cube[l, :, :] = add_ADR(cube[l, :, :], head, adrvals[l], 'spline3')
#Convolve cube channel with PSF channel
channel = psf_convolve(cube[l, :, :], psf)
#Convolve cube channel with instrument PSF
channel = psf_convolve(channel, instpsf)
#Frebin datacube up to output spaxel scale
newsize = (int(newsize[0]), int(newsize[1]))
channel *= (head['CDELT1'] * head['CDELT2'] * 1.E-6)
channel = frebin(channel, (newsize[0], newsize[1]), total=True)
channel /= (outspax[0] * outspax[1] * 1.E-6)
#Correct ADR effect
if adr_switch == 'ON':
adrhead = head.copy()
adrhead['CDELT1'] = outspax[0]
adrhead['CDELT2'] = outspax[1]
channel = add_ADR(channel, adrhead, -1. * adrvals[l], 'spline3')
#Add channel to output cube
out_cube[l, :, :] = channel
return out_cube, head
def pp_wavelength_channel(chann, head, wave, l, AO, psfvars, adrval, newsize,
outspax, adr_switch):
'''Function to take input datacube and process it iteratively through
each wavelength channel as follows:
- Generate PSF array for given channel
- Add effect of ADR to channel
- Convolve cube channel with PSF
- Frebin up to chosen output spaxel scale
Inputs:
chann: cube channel
head: Datacube header
wave: wavelength [um]
l: iteration no.
out_cube: Empty output cube
AO: AO mode [LTAO, SCAO, Gaussian]
psfvars: list containing [psfparams, psfspax, psfsize,
[D,eps], res_jitter, seeing, user_psf,
user_psflams]
adrval: ADR value
newsize: tuple containing (x_newsize, y_newsize) array sizes
outspax: tuple containing (x, y) output spaxel scales
adr_switch: On or OFF. Turns ADR effect on or off
Output:
cube: Processed cube
head: Updated header
inspax: Input spaxel scale (mas, mas)
outspax: Output spaxel scale (mas, mas)
'''
#Create PSF channel
#If user PSF and 2D image
upsf = psfvars[-2]
upsflams = psfvars[-1]
if type(upsf) != str and type(upsflams) == str:
psf = upsf
#If User PSF and 3D cube
elif type(upsf) != str and type(upsflams) != str:
#Interpolate PSF cube
interp = interp1d(upsflams, upsf, axis=0)
psf = interp(wave)
elif AO == 'LTAO' or AO == 'SCAO' or AO == 'GLAO':
psf = create_psf_channel(psfvars[0], l, psfvars[1],
(head['CDELT1'], head['CDELT2']), psfvars[2],
psfvars[3], psfvars[4])
elif AO == 'Gaussian':
psf = create_Gausspsf_channel(wave, psfvars[5], psfvars[3], psfvars[4],
psfvars[2], False, psfvars[1],
(head['CDELT1'], head['CDELT2']))
else:
print 'AO = ', AO
raise ValueError('AO choice or user_PSF error!')
#Create instrument PSF array
instpsf = create_instpsf(psfvars[2], psfvars[1], outspax,
(head['CDELT1'], head['CDELT2']))
#Add ADR effect to channel
if adr_switch == 'ON':
chann = add_ADR(chann, head, adrval, 'spline3')
#Convolve cube channel with PSF channel
chann = psf_convolve(chann, psf)
#Convolve cube channel with instrument PSF
chann = psf_convolve(chann, instpsf)
#Frebin datacube up to output spaxel scale
newsize = (int(newsize[0]), int(newsize[1]))
chann *= (head['CDELT1'] * head['CDELT2'] * 1.E-6)
chann = frebin(chann, (newsize[0], newsize[1]), total=True)
chann /= (outspax[0] * outspax[1] * 1.E-6)
#"Correct" ADR effect
if adr_switch == 'ON':
adrhead = head.copy()
adrhead['CDELT1'] = outspax[0]
adrhead['CDELT2'] = outspax[1]
chann = add_ADR(chann, adrhead, -1. * adrval, 'spline3')
return chann, l
def spectral_res(datacube, head, grating, wavels, gratings, spec_nyquist=True, spec_samp=1.):
'''Function that takes input datacube and rebins it to the
chosen spectral resolution. It convolves datacube along wavelength
axis, interpolates all spaxels along wavelength axis then extracts
pixel vales for each datacube wavelength channel. Function combines both
spectral resolution choice and datacube chopping in wavelength axis.
Option of bypassing spectral processing by setting band=='None' and
spec_nyquist=True - this ignores wavelength dimension.
Inputs:
datacube: object datacube
head: header file for object datacube
grating: string representing chosen grating. Grating choice sets R and wavelength range
wavels: wavelength array for datacube
gratings: dictionary of grating parameters (lambda_min, lambda_max, R)
spec_nyquist: Boolean - if True, 2 pixels per resolution element.
- if False, uses spec_samp value
Outputs:
scaled_cube: rebinned datacube
head: updated header file
new_wavels: new wavelength array for datacube
delta_lambda: New resolution [um]
lamb_per_pix: pixel dispersion [um/pixel]
bandws[2]: output R
'''
print 'Spectral resolution and wavelength range.'
print 'Chosen grating: ', grating
bandws = gratings[grating]
z, y, x = datacube.shape
if bandws == None and spec_nyquist==False:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3']
elif bandws != None and spec_nyquist==True:
new_res = (bandws[0]+bandws[1])/(2.*bandws[2])
lamb_per_pix = new_res/2.
elif bandws != None and spec_nyquist==False:
new_res = (bandws[0]+bandws[1])/(2.*bandws[2])
lamb_per_pix = spec_samp/10000.
elif bandws == None and spec_nyquist==True:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3'], 0
else:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3'], 0
print 'Current resolution = %.5f microns' % head['SPECRES']
print 'Current sampling = %.5f microns' % head['CDELT3']
print 'New resolution = %.5f microns' % new_res
print 'New sampling = %.5f microns' % lamb_per_pix
if head['SPECRES'] >= new_res:
print 'WARNING: Input spectral resolution is coarser (or equal) than chosen output!'
#Chose whether to convolve with LSF or simply resample.
condition = raw_input('Do you want to convolve with Gaussian LSF of FWHM'
' given by band and chosen resolving power [y], or not [any other key]?: ')
if condition=='y':
print 'Convolving with LSF'
#Generate Gaussian LSF of FWHM = (bandws[0]+bandws[1])/(2.*R)
sig = new_res/(2.*n.sqrt(2.*n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:,1], axis=0)
else:
print 'Input spectral resolution smaller than chosen output.'
print 'Convolving with corresponding LSF.'
#Generate Gaussian LSF of FWHM = sqrt(new_resolution**2-head['SPECRES']**2)
sig = n.sqrt(new_res**2-head['SPECRES']**2)/(2.*n.sqrt(2.*n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:,1], axis=0)
## #New wavelength values from chosen photometric band (or ignore)
## if bandws:
## new_wavels = n.arange(bandws[0], bandws[1], lamb_per_pix)
## new_wavels[-1] = bandws[1]
## #Slice datacube down to size of new wavelength array
## start = n.where(wavels < new_wavels[0])[0][-1]
## end = n.where(wavels > new_wavels[-1])[0][0]
## datacube = datacube[start:end+1,:,:]
## elif not bandws:
## new_wavels = n.arange(wavels[0], wavels[-1], lamb_per_pix)
## new_wavels[-1] = wavels[-1]
#####
#Interpolate datacube onto regular pixel grid (irregular wavelength grid) with 10x hypersampling
if wavels[0] <= bandws[0] and wavels[-1] >= bandws[1]:#cube wavelength range larger than grating choice
print 'Cube wavelength range larger than grating: chopping down to grating range'
new_wavels = n.arange(bandws[0], bandws[1]+lamb_per_pix/2., lamb_per_pix)
new_wavels[-1] = bandws[1]
start = n.where(wavels <= new_wavels[0])[0][-1]
end = n.where(wavels >= new_wavels[-1])[0][0]
#datacube = datacube[start:end+1,:,:]
elif wavels[0] > bandws[0] and wavels[-1] < bandws[1]:#cube wavelength range inside grating choice
print 'Cube wavelength range inside grating range'
new_wavels = n.arange(wavels[0], wavels[-1]+lamb_per_pix/2., lamb_per_pix)
new_wavels[-1] = wavels[-1]
start = n.where(bandws[0] < wavels)[0][0]
end = n.where(bandws[1] > wavels)[0][-1]
#datacube = datacube[start:end+1,:,:]
elif wavels[0] > bandws[0]:#cube short wavelength longer than grating shortest wavelength
print 'Cube shortest wavelength larger than grating'
new_wavels = n.arange(wavels[0], bandws[1]+lamb_per_pix/2., lamb_per_pix)
new_wavels[-1] = bandws[1]
start = n.where(bandws[0] < wavels)[0][0]
end = n.where(bandws[1] > wavels)[0][-1]
#datacube = datacube[start:end+1,:,:]
elif wavels[-1] < bandws[1]:#cube longest wavelength shorter than grating longest wavelength
print 'Cube longest wavelength shorter than grating'
new_wavels = n.arange(bandws[0], wavels[-1]+lamb_per_pix/2., lamb_per_pix)
new_wavels[-1] = wavels[-1]
start = n.where(bandws[0] < wavels)[0][0]
end = n.where(bandws[1] > wavels)[0][-1]
#datacube = datacube[start:end+1,:,:]
else:
raise ValueError('Specres wavelength error!!!')
#####
new_cube = n.zeros((len(new_wavels), y, x), dtype=float)
###New 30-05-14
#Put datacube flux into photon units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head['FUNITS'] == 'J/s/m2/A/arcsec2':
datacube *= (head['CDELT3']*10000.)
else:
datacube *= head['CDELT3']
#print 'Datacube sum = ', datacube.sum()
#Bin up in spectral dimension to new pixel sampling
#Iterate over x-axis and use frebin function on 2D y-z arrays
for i in xrange(x):
new_cube[:,:,i] = frebin(datacube[start:end+1,:,i], (y,len(new_wavels)), True)
#print 'New cube sum = ', new_cube.sum()
#Put datacube flux back into photons/wavelength units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head['FUNITS'] == 'J/s/m2/A/arcsec2':
new_cube /= (lamb_per_pix*10000.)
else:
new_cube /= lamb_per_pix
#Update header
head['CRVAL3'] = new_wavels[0]
head['CDELT3'] = (new_wavels[1]-new_wavels[0])
head['NAXIS3'] = len(new_wavels)
head['SPECRES'] = new_res
print 'Spectral resolution and wavelength range - done!'
#Return new_datacube, new_wavels, updated_header
return new_cube, head, new_wavels, new_res, lamb_per_pix, bandws[2]
def spectral_res(datacube, head, R, band, wavels, spec_nyquist=True, spec_samp=1.):
'''Function that takes input datacube and rebins it to the
chosen spectral resolution. It convolves datacube along wavelength
axis, interpolates all spaxels along wavelength axis then extracts
pixel vales for each datacube wavelength channel. Function combines both
spectral resolution choice and datacube chopping in wavelength axis.
Option of bypassing spectral processing by setting band=='None' and
spec_nyquist=True - this ignores wavelength dimension.
Inputs:
datacube: object datacube
head: header file for object datacube
R: spectral resolving power
band: string representing wavelength band choice.
Option of "None" which ignores photometric bands.
wavels: wavelength array for datacube
spec_nyquist: Boolean - if True, 2 pixels per resolution element.
- if False, uses spec_samp value
Outputs:
scaled_cube: rebinned datacube
head: updated header file
new_wavels: new wavelength array for datacube
delta_lambda: New resolution [um]
lamb_per_pix: pixel dispersion [um/pixel]
'''
print 'Spectral resolution and wavelength range.'
print 'Chosen resolution: ', R
print 'Chosen band: ', band
bands = {'V':(.47,.63),'R':(.63,.79), 'Iz':(.82,1.03),
'J':(1.08,1.36), 'H':(1.46,1.83), 'K':(1.95,2.45),
'V+R':(.47,.81), 'Iz+J':(.8,1.36), 'H+K':(1.45,2.45),
'V-high':(.53,.59), 'R-high':(.61,.68),
'z':(.82,.91), 'J-high':(1.17,1.29),
'H-high':(1.545,1.715), 'K-high':(2.09,2.32),
'None':None}
bandws = bands[band]
z, y, x = datacube.shape
if bandws == None and spec_nyquist==False:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3']
elif bandws != None and spec_nyquist==True:
new_res = (bandws[0]+bandws[1])/(2.*R)
lamb_per_pix = new_res/2.
elif bandws != None and spec_nyquist==False:
new_res = (bandws[0]+bandws[1])/(2.*R)
lamb_per_pix = spec_samp/10000.
elif bandws == None and spec_nyquist==True:
#no convolution, just interpolate and read out new wavelengths
#when sig=0, gauss returns [1.,1.] so convolution does nothing.
# new_res = head['SPECRES']
new_res = (wavels[0]+wavels[-1])/(2.*R)
lamb_per_pix = new_res/2.
else:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3']
print 'Current resolution = %.5f microns' % head['SPECRES']
print 'Current sampling = %.5f microns' % head['CDELT3']
print 'New resolution = %.5f microns' % new_res
print 'New sampling = %.5f microns' % lamb_per_pix
if head['SPECRES'] >= new_res:
print 'WARNING: Input spectral resolution is coarser (or equal) than chosen output!'
#Chose whether to convolve with LSF or simply resample.
condition = raw_input('Do you want to convolve with Gaussian LSF of FWHM'
' given by band and chosen resolving power [y], or not [any other key]?: ')
if condition=='y':
print 'Convolving with LSF'
#Generate Gaussian LSF of FWHM = (bandws[0]+bandws[1])/(2.*R)
sig = new_res/(2.*n.sqrt(2.*n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:,1], axis=0)
else:
print 'Input spectral resolution smaller than chosen output.'
print 'Convolving with corresponding LSF.'
#Generate Gaussian LSF of FWHM = sqrt(new_resolution**2-head['SPECRES']**2)
sig = n.sqrt(new_res**2-head['SPECRES']**2)/(2.*n.sqrt(2.*n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:,1], axis=0)
#New wavelength values from chosen photometric band (or ignore)
if bandws:
new_wavels = n.arange(bandws[0], bandws[1], lamb_per_pix)
new_wavels[-1] = bandws[1]
#Slice datacube down to size of new wavelength array
start = n.where(wavels < new_wavels[0])[0][-1]
end = n.where(wavels > new_wavels[-1])[0][0]
datacube = datacube[start:end+1,:,:]
elif not bandws:
new_wavels = n.arange(wavels[0], wavels[-1], lamb_per_pix)
new_wavels[-1] = wavels[-1]
new_cube = n.zeros((len(new_wavels), y, x), dtype=float)
###New 30-05-14
#Put datacube flux into photon units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head['FUNITS'] == 'J/s/m2/A/arcsec2':
datacube *= (head['CDELT3']*10000.)
else:
datacube *= head['CDELT3']
#print 'Datacube sum = ', datacube.sum()
#Bin up in spectral dimension to new pixel sampling
#Iterate over x-axis and use frebin function on 2D y-z arrays
for i in xrange(x):
new_cube[:,:,i] = frebin(datacube[:,:,i], (y,len(new_wavels)),True)
#print 'New cube sum = ', new_cube.sum()
#Put datacube flux back into photons/wavelength units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head['FUNITS'] == 'J/s/m2/A/arcsec2':
new_cube /= (lamb_per_pix*10000.)
else:
new_cube /= lamb_per_pix
#Update header
head.update('CRVAL3', new_wavels[0])
head.update('CDELT3', (new_wavels[1]-new_wavels[0]))
head.update('NAXIS3', len(new_wavels))
head.update('SPECRES', new_res)
print 'Spectral resolution and wavelength range - done!'
#Return new_datacube, new_wavels, updated_header
return new_cube, head, new_wavels, new_res, lamb_per_pix
def spectral_res(datacube,
head,
grating,
wavels,
gratings,
spec_nyquist=True,
spec_samp=1.,
ignoreLSF=False):
'''Function that takes input datacube and rebins it to the
chosen spectral resolution. It convolves datacube along wavelength
axis, interpolates all spaxels along wavelength axis then extracts
pixel vales for each datacube wavelength channel. Function combines both
spectral resolution choice and datacube chopping in wavelength axis.
Option of bypassing spectral processing by setting band=='None' and
spec_nyquist=True - this ignores wavelength dimension.
Inputs:
datacube: object datacube
head: header file for object datacube
grating: string representing chosen grating. Grating choice sets R and wavelength range
wavels: wavelength array for datacube
gratings: dictionary of grating parameters (lambda_min, lambda_max, R)
spec_nyquist: Boolean - if True, 2 pixels per resolution element.
- if False, uses spec_samp value
ignoreLSF: Boolean - ignore LSF convolution in spectral dimension
Outputs:
scaled_cube: rebinned datacube
head: updated header file
new_wavels: new wavelength array for datacube
delta_lambda: New resolution [um]
lamb_per_pix: pixel dispersion [um/pixel]
resol: output R
'''
print 'Spectral resolution and wavelength range.'
print 'Chosen grating: ', grating
bandws = gratings[grating]
z, y, x = datacube.shape
if ignoreLSF == True:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3'], 0
if bandws == None and spec_nyquist == False:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3'], 0
elif bandws != None and spec_nyquist == True:
#new_res = (bandws[0]+bandws[1])/(2.*bandws[2])
new_res = bandws[2]
lamb_per_pix = new_res / 2.
elif bandws != None and spec_nyquist == False:
#new_res = (bandws[0]+bandws[1])/(2.*bandws[2])
new_res = bandws[2]
lamb_per_pix = spec_samp / 10000.
elif bandws == None and spec_nyquist == True:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3'], 0
else:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3'], 0
print 'Current resolution = %.5f microns' % head['SPECRES']
print 'Current sampling = %.5f microns' % head['CDELT3']
print 'New resolution = %.5f microns' % new_res
print 'New sampling = %.5f microns' % lamb_per_pix
if head['SPECRES'] >= new_res:
print 'WARNING: Input spectral resolution is coarser (or equal) than chosen output!'
#Chose whether to convolve with LSF or simply resample.
condition = raw_input(
'Do you want to convolve with Gaussian LSF of FWHM'
' given by band and chosen resolving power [y], or not [any other key]?: '
)
if condition == 'y':
print 'Convolving with LSF'
#Generate Gaussian LSF of FWHM = (bandws[0]+bandws[1])/(2.*R)
sig = new_res / (2. * n.sqrt(2. * n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:, 1], axis=0)
else:
print 'Input spectral resolution smaller than chosen output.'
print 'Convolving with corresponding LSF.'
#Generate Gaussian LSF of FWHM = sqrt(new_resolution**2-head['SPECRES']**2)
sig = n.sqrt(new_res**2 -
head['SPECRES']**2) / (2. * n.sqrt(2. * n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:, 1], axis=0)
## #New wavelength values from chosen photometric band (or ignore)
## if bandws:
## new_wavels = n.arange(bandws[0], bandws[1], lamb_per_pix)
## new_wavels[-1] = bandws[1]
## #Slice datacube down to size of new wavelength array
## start = n.where(wavels < new_wavels[0])[0][-1]
## end = n.where(wavels > new_wavels[-1])[0][0]
## datacube = datacube[start:end+1,:,:]
## elif not bandws:
## new_wavels = n.arange(wavels[0], wavels[-1], lamb_per_pix)
## new_wavels[-1] = wavels[-1]
#####
#Interpolate datacube onto regular pixel grid (irregular wavelength grid) with 10x hypersampling
if wavels[0] <= bandws[0] and wavels[-1] >= bandws[
1]: #cube wavelength range larger than grating choice
print 'Cube wavelength range larger than grating: chopping down to grating range'
new_wavels = n.arange(bandws[0], bandws[1] + lamb_per_pix / 2.,
lamb_per_pix)
new_wavels[-1] = bandws[1]
start = n.where(wavels <= new_wavels[0])[0][-1]
end = n.where(wavels >= new_wavels[-1])[0][0]
#datacube = datacube[start:end+1,:,:]
elif wavels[0] > bandws[0] and wavels[-1] < bandws[
1]: #cube wavelength range inside grating choice
print 'Cube wavelength range inside grating range'
new_wavels = n.arange(wavels[0], wavels[-1] + lamb_per_pix / 2.,
lamb_per_pix)
new_wavels[-1] = wavels[-1]
start = n.where(bandws[0] < wavels)[0][0]
end = n.where(bandws[1] > wavels)[0][-1]
#datacube = datacube[start:end+1,:,:]
elif wavels[0] > bandws[
0]: #cube short wavelength longer than grating shortest wavelength
print 'Cube shortest wavelength larger than grating'
new_wavels = n.arange(wavels[0], bandws[1] + lamb_per_pix / 2.,
lamb_per_pix)
new_wavels[-1] = bandws[1]
start = n.where(bandws[0] < wavels)[0][0]
end = n.where(bandws[1] > wavels)[0][-1]
#datacube = datacube[start:end+1,:,:]
elif wavels[-1] < bandws[
1]: #cube longest wavelength shorter than grating longest wavelength
print 'Cube longest wavelength shorter than grating'
new_wavels = n.arange(bandws[0], wavels[-1] + lamb_per_pix / 2.,
lamb_per_pix)
new_wavels[-1] = wavels[-1]
start = n.where(bandws[0] < wavels)[0][0]
end = n.where(bandws[1] > wavels)[0][-1]
#datacube = datacube[start:end+1,:,:]
else:
raise ValueError('Specres wavelength error!!!')
#####
new_cube = n.zeros((len(new_wavels), y, x), dtype=float)
###New 30-05-14
#Put datacube flux into photon units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head[
'FUNITS'] == 'J/s/m2/A/arcsec2':
datacube *= (head['CDELT3'] * 10000.)
else:
datacube *= head['CDELT3']
#print 'Datacube sum = ', datacube.sum()
#Bin up in spectral dimension to new pixel sampling
#Iterate over x-axis and use frebin function on 2D y-z arrays
for i in xrange(x):
new_cube[:, :, i] = frebin(datacube[start:end + 1, :, i],
(y, len(new_wavels)), True)
#print 'New cube sum = ', new_cube.sum()
#Put datacube flux back into photons/wavelength units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head[
'FUNITS'] == 'J/s/m2/A/arcsec2':
new_cube /= (lamb_per_pix * 10000.)
else:
new_cube /= lamb_per_pix
#Update header
head['CRVAL3'] = new_wavels[0]
head['CDELT3'] = (new_wavels[1] - new_wavels[0])
head['NAXIS3'] = len(new_wavels)
head['SPECRES'] = new_res
resol = n.round(new_wavels[len(new_wavels) / 2] / bandws[2], 0)
print 'Spectral resolution and wavelength range - done!'
#Return new_datacube, new_wavels, updated_header
return new_cube, head, new_wavels, new_res, lamb_per_pix, resol
def spectral_res(datacube,
head,
R,
band,
wavels,
spec_nyquist=True,
spec_samp=1.):
'''Function that takes input datacube and rebins it to the
chosen spectral resolution. It convolves datacube along wavelength
axis, interpolates all spaxels along wavelength axis then extracts
pixel vales for each datacube wavelength channel. Function combines both
spectral resolution choice and datacube chopping in wavelength axis.
Option of bypassing spectral processing by setting band=='None' and
spec_nyquist=True - this ignores wavelength dimension.
Inputs:
datacube: object datacube
head: header file for object datacube
R: spectral resolving power
band: string representing wavelength band choice.
Option of "None" which ignores photometric bands.
wavels: wavelength array for datacube
spec_nyquist: Boolean - if True, 2 pixels per resolution element.
- if False, uses spec_samp value
Outputs:
scaled_cube: rebinned datacube
head: updated header file
new_wavels: new wavelength array for datacube
delta_lambda: New resolution [um]
lamb_per_pix: pixel dispersion [um/pixel]
'''
print 'Spectral resolution and wavelength range.'
print 'Chosen resolution: ', R
print 'Chosen band: ', band
bands = {
'V': (.47, .63),
'R': (.63, .79),
'Iz': (.82, 1.03),
'J': (1.08, 1.36),
'H': (1.46, 1.83),
'K': (1.95, 2.45),
'V+R': (.47, .81),
'Iz+J': (.8, 1.36),
'H+K': (1.45, 2.45),
'V-high': (.53, .59),
'R-high': (.61, .68),
'z': (.82, .91),
'J-high': (1.17, 1.29),
'H-high': (1.545, 1.715),
'K-high': (2.09, 2.32),
'None': None
}
bandws = bands[band]
z, y, x = datacube.shape
if bandws == None and spec_nyquist == False:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3']
elif bandws != None and spec_nyquist == True:
new_res = (bandws[0] + bandws[1]) / (2. * R)
lamb_per_pix = new_res / 2.
elif bandws != None and spec_nyquist == False:
new_res = (bandws[0] + bandws[1]) / (2. * R)
lamb_per_pix = spec_samp / 10000.
elif bandws == None and spec_nyquist == True:
#no convolution, just interpolate and read out new wavelengths
#when sig=0, gauss returns [1.,1.] so convolution does nothing.
# new_res = head['SPECRES']
new_res = (wavels[0] + wavels[-1]) / (2. * R)
lamb_per_pix = new_res / 2.
else:
print 'Ignoring spectral dimension!'
return datacube, head, wavels, head['SPECRES'], head['CDELT3']
print 'Current resolution = %.5f microns' % head['SPECRES']
print 'Current sampling = %.5f microns' % head['CDELT3']
print 'New resolution = %.5f microns' % new_res
print 'New sampling = %.5f microns' % lamb_per_pix
if head['SPECRES'] >= new_res:
print 'WARNING: Input spectral resolution is coarser (or equal) than chosen output!'
#Chose whether to convolve with LSF or simply resample.
condition = raw_input(
'Do you want to convolve with Gaussian LSF of FWHM'
' given by band and chosen resolving power [y], or not [any other key]?: '
)
if condition == 'y':
print 'Convolving with LSF'
#Generate Gaussian LSF of FWHM = (bandws[0]+bandws[1])/(2.*R)
sig = new_res / (2. * n.sqrt(2. * n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:, 1], axis=0)
else:
print 'Input spectral resolution smaller than chosen output.'
print 'Convolving with corresponding LSF.'
#Generate Gaussian LSF of FWHM = sqrt(new_resolution**2-head['SPECRES']**2)
sig = n.sqrt(new_res**2 -
head['SPECRES']**2) / (2. * n.sqrt(2. * n.log(2.)))
gauss_array = Gauss(sig, head['CDELT3'])
#Convolve datacube array with Gaussian along wavelength axis
datacube = convolve1d(datacube, gauss_array[:, 1], axis=0)
#New wavelength values from chosen photometric band (or ignore)
if bandws:
new_wavels = n.arange(bandws[0], bandws[1], lamb_per_pix)
new_wavels[-1] = bandws[1]
#Slice datacube down to size of new wavelength array
start = n.where(wavels < new_wavels[0])[0][-1]
end = n.where(wavels > new_wavels[-1])[0][0]
datacube = datacube[start:end + 1, :, :]
elif not bandws:
new_wavels = n.arange(wavels[0], wavels[-1], lamb_per_pix)
new_wavels[-1] = wavels[-1]
new_cube = n.zeros((len(new_wavels), y, x), dtype=float)
###New 30-05-14
#Put datacube flux into photon units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head[
'FUNITS'] == 'J/s/m2/A/arcsec2':
datacube *= (head['CDELT3'] * 10000.)
else:
datacube *= head['CDELT3']
#print 'Datacube sum = ', datacube.sum()
#Bin up in spectral dimension to new pixel sampling
#Iterate over x-axis and use frebin function on 2D y-z arrays
for i in xrange(x):
new_cube[:, :, i] = frebin(datacube[:, :, i], (y, len(new_wavels)),
True)
#print 'New cube sum = ', new_cube.sum()
#Put datacube flux back into photons/wavelength units
if head['FUNITS'] == 'erg/s/cm2/A/arcsec2' or head[
'FUNITS'] == 'J/s/m2/A/arcsec2':
new_cube /= (lamb_per_pix * 10000.)
else:
new_cube /= lamb_per_pix
#Update header
head.update('CRVAL3', new_wavels[0])
head.update('CDELT3', (new_wavels[1] - new_wavels[0]))
head.update('NAXIS3', len(new_wavels))
head.update('SPECRES', new_res)
print 'Spectral resolution and wavelength range - done!'
#Return new_datacube, new_wavels, updated_header
return new_cube, head, new_wavels, new_res, lamb_per_pix
