def get_gauss_beam(fwhm, pixscale, nfwhm=5.0, oversamp=5):
""" Generate Gaussian kernel
Parameters
----------
fwhm: float
FWHM of the Gaussian beam.
pixscale: float
Pixel scale, in same units as FWHM.
nfwhm: float
Number of fwhm (approximately) of each dimension of the output beam.
oversamp: int
Odd integer giving the oversampling to use when constructing the
beam. The beam is generated in pixscale / oversamp size pixels,
then rebinned to pixscale.
Notes
-----
The beam is normalized by having a value of 1 in the center.
If oversampling is used, the returned array will be the sum over
the neighborhood of this maximum, so will not be one.
"""
if fwhm <= 0:
raise ValueError("Invalid (negative) FWHM")
if pixscale <= 0:
raise ValueError("Invalid (negative) pixel scale")
if nfwhm <= 0.0:
raise ValueError("Invalid (non-positive) nfwhm")
if fwhm / pixscale < 2.5:
raise ValueError("Insufficiently well sampled beam")
if oversamp < 1:
raise ValueError("Invalid (<1) oversampling")
retext = round(fwhm * nfwhm / pixscale)
if retext % 2 == 0:
retext += 1
bmsigma = fwhm / math.sqrt(8 * math.log(2))
if oversamp == 1:
# Easy case
beam = make_kernel((retext, retext), bmsigma / pixscale,
'gaussian').astype(np.float32)
beam /= beam.max
else:
genext = retext * oversamp
genpixscale = pixscale / oversamp
gbeam = make_kernel((genext, genext), bmsigma / genpixscale,
'gaussian').astype(np.float32)
gbeam /= gbeam.max() # Normalize -before- rebinning
# Rebinning -- tricky stuff!
bmview = gbeam.reshape(retext, oversamp, retext, oversamp)
beam = bmview.mean(axis=3).mean(axis=1)
return beam
def plot_2005ip():
'''
Create a plot of the combined NUV and FUV spectrum of SN 2005ip, label the common SN
lines with different colors for different species and save
'''
redshift = 0.0072
tbdata = fits.getdata('2005ip_all_x1dsum.fits', 1)
sdqflags = fits.getval('2005ip_all_x1dsum.fits', 'sdqflags', 1)
good_indx = np.where(tbdata['dq'][0] & sdqflags == 0)
fig = pyplot.figure(figsize=[20, 10])
ax = fig.add_subplot(1, 1, 1)
deredshift_wl = deredshift_wavelength(tbdata['wavelength'][0][good_indx],
redshift)
smoothed_signal = convolve.convolve(
tbdata['flux'][0][good_indx],
make_kernel.make_kernel([15], 15, 'boxcar'))
ax.plot(deredshift_wl, smoothed_signal, 'b')
ax = label_spectra(ax)
ax.set_xlabel('Rest Wavelength ($\AA$)')
ax.set_ylabel('Flux (ergs/cm^2/s/$\AA$)')
ax.set_title(
'Preliminary HST/STIS Spectrum of SN 2005ip (smoothed by 15 pix)')
ax.set_ylim(-0.1E-15, 0.25E-15)
add_date_to_plot(ax)
pyplot.savefig('2005ip_combined_labeled.pdf')
def plot_2009ip():
'''
Create a plot of the combined NUV and FUV spectrum of SN 2009ip, label the common SN
lines with different colors for different species and save
'''
redshift = 0.0072
tbdata = fits.getdata('2009ip_all_x1dsum.fits', 1)
sdqflags = fits.getval('2009ip_all_x1dsum.fits', 'sdqflags', 1)
good_indx = np.where(tbdata['dq'][0]&sdqflags == 0)
fig = pyplot.figure(figsize = [20, 10])
ax = fig.add_subplot(1,1,1)
deredshift_wl = deredshift_wavelength(tbdata['wavelength'][0][good_indx], redshift)
smoothed_signal = convolve.convolve(tbdata['flux'][0][good_indx], make_kernel.make_kernel([15],15,'boxcar'))
ax.plot(deredshift_wl, smoothed_signal, 'b')
ax = label_spectra(ax)
ax.set_xlabel('Rest Wavelength ($\AA$)')
ax.set_ylabel('Flux (ergs/cm^2/s/$\AA$)')
ax.set_title('Preliminary HST/STIS Spectrum of SN 2009ip (smoothed by 15 pix)')
ax.set_ylim(-0.1E-15, 0.25E-15)
add_date_to_plot(ax)
pyplot.savefig('2009ip_combined_labeled.pdf')
m1 = data[x].mapstruct.map[0]
m2 = data[y].mapstruct.map[0]
yy1, xx1 = grid1 = np.indices(m1.shape)
ratio = m2.shape[0] / float(m1.shape[0])
newm2 = scipy.ndimage.map_coordinates(np.nan_to_num(m2), grid1 * ratio)
mask = (m1 == m1) * (newm2 == newm2) * (m1 > 0) * (newm2 > 0)
#mask *= (m1>m1[mask].std()) * (newm2>newm2[mask].std())
rr = ((xx1 - m1.shape[1] / 3.)**2 + (yy1 - m1.shape[0] / 3.)**2)**0.5
#mask *= rr < 5
beamsize_delta = (np.abs(data[y].mapstruct['OMEGA_BEAM_AM'] -
data[x].mapstruct['OMEGA_BEAM_AM']) / np.pi /
2)**0.5
am_per_pix = data[y].mapstruct['OMEGA_PIX_AM']**0.5
kernelwidth = beamsize_delta / am_per_pix
kernel = make_kernel.make_kernel(
m1.shape, kernelwidth=kernelwidth) #, normalize_kernel=np.max)
newm1 = convolve.convolve_fft(m1, kernel, interpolate_nan=True)
newm1 *= data[y].mapstruct['OMEGA_BEAM_AM'] / data[x].mapstruct[
'OMEGA_BEAM_AM']
plot(newm1[mask], newm2[mask], 'o', alpha=0.5)
#kernel = make_kernel.make_kernel(m1.shape, kernelwidth=5)
#smm1 = convolve.convolve_fft(newm1,kernel, interpolate_nan=True)
#smm2 = convolve.convolve_fft(newm2,kernel, interpolate_nan=True)
#plot((newm1-smm1)[mask],(newm2-smm2)[mask],'rs', alpha=0.5)
xx = np.linspace(newm1[mask].min(), newm1[mask].max())
plot(xx, xx * (band_waves[x] / band_waves[y])**3.5, 'r--')
plot(xx, xx * (band_waves[x] / band_waves[y])**2, 'b:')
subplots_adjust(hspace=0.3, wspace=0.3)
def convolve_and_match(data, objectname, clobber=True, writefits=True, unsharpscale=80):
"""
Convolve all bands to Band 0 resolution and resample all to Band 3
pixelization. The data values are appropriately scaled after smoothing
such that they are in units of mJy/beam, where the beam is the Band 0 beam.
Sanity checks on this front are warranted.
Parameters
----------
data : dict of IDLSAVE structs
objectname : str
Object name for saving purposes
clobber : bool
Overwrite FITS files if they exist?
writefits : bool
Write the fits files to disk?
unsharpscale : float
Unsharp mask angular scale in arcseconds
Returns
-------
smoothdict : dict
A dictionary of band number : smoothed & resampled map
unsharpdict : dict
A dictionary of band number : unsharp-masked map
"""
smoothed = {}
unsharped = {}
# the band 3 map is used as the reference pixel scale
band3 = data[3].mapstruct.map[0]
yy1,xx1 = grid1 = np.indices(band3.shape)
pixscale = float(data[3].mapstruct['OMEGA_PIX_AM']**0.5 / 60.)
pixscale_as = pixscale*3600
if writefits:
header = fits.Header()
header['CDELT1'] = pixscale
header['CDELT2'] = pixscale
ffile = fits.PrimaryHDU(data=band3, header=header)
for ii in xrange(4):
# grab the map from band i
m = data[ii].mapstruct.map[0]
# ratio of map sizes (assumes they're symmetric, sort of)
ratio = m.shape[0]/float(band3.shape[0])
# rescale the band i map to band3 scale
newm = scipy.ndimage.map_coordinates(np.nan_to_num(m), grid1*ratio)
# flag out the NANs again (we had to make them zeros for the previous step to work)
bads = scipy.ndimage.map_coordinates(np.array(m!=m,dtype='float'), grid1*ratio)
newm[bads>0.5] = np.nan
# Determine the appropriate convolution kernel size
# beamsize = np.array([60*(v.mapstruct.omega_beam_am/np.pi/2.)**0.5 * (8*np.log(2))**0.5 for v in data.values()]).ravel()
# array([ 45.00000061, 31.00000042, 25.00000034, 23.00000031])
# these check out...
beamsize_delta = (np.abs(data[ii].mapstruct['OMEGA_BEAM_AM']-data[0].mapstruct['OMEGA_BEAM_AM'])/np.pi/2)**0.5
# pixel scale in the *output* image
am_per_pix = data[3].mapstruct['OMEGA_PIX_AM']**0.5
# kernel width in pixels
kernelwidth = beamsize_delta/am_per_pix
if kernelwidth > 0:
kernel = make_kernel.make_kernel(band3.shape, kernelwidth=kernelwidth)
newm = convolve.convolve_fft(newm, kernel, interpolate_nan=True)
# rescale the values to be mJy per a much larger beam; the values should therefore be larger
newm *= data[0].mapstruct['OMEGA_BEAM_AM']/data[ii].mapstruct['OMEGA_BEAM_AM']
# Now do an unsharp mask with a fairly large kernel to ensure the spatial filters are identical
kernel = make_kernel.make_kernel(band3.shape, kernelwidth=unsharpscale/pixscale_as)
smm = convolve.convolve_fft(newm,kernel, interpolate_nan=True)
smoothed[ii] = newm
unsharped[ii] = newm-smm
if writefits:
ffile.data = newm
ffile.writeto("%s_Band%i_smooth.fits" % (objectname,ii), clobber=clobber)
ffile.data = newm - smm
ffile.writeto("%s_Band%i_smooth_unsharp.fits" % (objectname,ii), clobber=clobber)
return smoothed,unsharped
m1 = data[x].mapstruct.map[0]
m2 = data[y].mapstruct.map[0]
yy1, xx1 = grid1 = np.indices(m1.shape)
ratio = m2.shape[0] / float(m1.shape[0])
newm2 = scipy.ndimage.map_coordinates(np.nan_to_num(m2), grid1 * ratio)
mask = (m1 == m1) * (newm2 == newm2) * (m1 > 0) * (newm2 > 0)
# mask *= (m1>m1[mask].std()) * (newm2>newm2[mask].std())
rr = ((xx1 - m1.shape[1] / 3.0) ** 2 + (yy1 - m1.shape[0] / 3.0) ** 2) ** 0.5
# mask *= rr < 5
beamsize_delta = (
np.abs(data[y].mapstruct["OMEGA_BEAM_AM"] - data[x].mapstruct["OMEGA_BEAM_AM"]) / np.pi / 2
) ** 0.5
am_per_pix = data[y].mapstruct["OMEGA_PIX_AM"] ** 0.5
kernelwidth = beamsize_delta / am_per_pix
kernel = make_kernel.make_kernel(m1.shape, kernelwidth=kernelwidth) # , normalize_kernel=np.max)
newm1 = convolve.convolve_fft(m1, kernel, interpolate_nan=True)
newm1 *= data[y].mapstruct["OMEGA_BEAM_AM"] / data[x].mapstruct["OMEGA_BEAM_AM"]
plot(newm1[mask], newm2[mask], "o", alpha=0.5)
# kernel = make_kernel.make_kernel(m1.shape, kernelwidth=5)
# smm1 = convolve.convolve_fft(newm1,kernel, interpolate_nan=True)
# smm2 = convolve.convolve_fft(newm2,kernel, interpolate_nan=True)
# plot((newm1-smm1)[mask],(newm2-smm2)[mask],'rs', alpha=0.5)
xx = np.linspace(newm1[mask].min(), newm1[mask].max())
plot(xx, xx * (band_waves[x] / band_waves[y]) ** 3.5, "r--")
plot(xx, xx * (band_waves[x] / band_waves[y]) ** 2, "b:")
subplots_adjust(hspace=0.3, wspace=0.3)
xlabel("Band %i: %0.2f mm" % (x, band_waves[x]))
