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FOC_Reduction/src/lib/plots.py

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Python
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"""
Library functions for displaying informations using matplotlib
prototypes :
- plot_obs(data_array, headers, shape, vmin, vmax, savename, plots_folder)
Plots whole observation raw data in given display shape
- polarization_map(Stokes_hdul, SNRp_cut, SNRi_cut, step_vec, savename, plots_folder, display)
Plots polarization map of polarimetric parameters saved in an HDUList
"""
import copy
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import Rectangle
from matplotlib.widgets import RectangleSelector
import matplotlib.font_manager as fm
from mpl_toolkits.axes_grid1.anchored_artists import AnchoredSizeBar, AnchoredDirectionArrows
from astropy.wcs import WCS
def princ_angle(ang):
"""
Return the principal angle in the 0-180° quadrant.
"""
while ang < 0.:
ang += 180.
while ang > 180.:
ang -= 180.
return ang
def sci_not(v,err,rnd=1):
"""
Return the scientifque error notation as a string.
"""
power = - int(('%E' % v)[-3:])+1
output = r"({0}".format(round(v*10**power,rnd))
if type(err) == list:
for error in err:
output += r" $\pm$ {0}".format(round(error*10**power,rnd))
else:
output += r" $\pm$ {0}".format(round(err*10**power,rnd))
return output+r")e{0}".format(-power)
def plot_obs(data_array, headers, shape=None, vmin=0., vmax=6., rectangle=None,
savename=None, plots_folder=""):
"""
Plots raw observation imagery with some information on the instrument and
filters.
----------
Inputs:
data_array : numpy.ndarray
Array of images (2D floats, aligned and of the same shape) of a
single observation with multiple polarizers of an instrument
headers : header list
List of headers corresponding to the images in data_array
shape : array-like of length 2, optional
Shape of the display, with shape = [#row, #columns]. If None, defaults
to the optimal square.
Defaults to None.
vmin : float, optional
Min pixel value that should be displayed.
Defaults to 0.
vmax : float, optional
Max pixel value that should be displayed.
Defaults to 6.
rectangle : numpy.ndarray, optional
Array of parameters for matplotlib.patches.Rectangle objects that will
be displayed on each output image. If None, no rectangle displayed.
Defaults to None.
savename : str, optional
Name of the figure the map should be saved to. If None, the map won't
be saved (only displayed).
Defaults to None.
plots_folder : str, optional
Relative (or absolute) filepath to the folder in wich the map will
be saved. Not used if savename is None.
Defaults to current folder.
"""
if shape is None:
shape = np.array([np.ceil(np.sqrt(data_array.shape[0])).astype(int),]*2)
fig, ax = plt.subplots(shape[0], shape[1], figsize=(10,10), dpi=200,
sharex=True, sharey=True)
for i, enum in enumerate(list(zip(ax.flatten(),data_array))):
ax = enum[0]
data = enum[1]
instr = headers[i]['instrume']
rootname = headers[i]['rootname']
exptime = headers[i]['exptime']
filt = headers[i]['filtnam1']
#plots
im = ax.imshow(data, vmin=vmin, vmax=vmax, origin='lower')
if not(rectangle is None):
x, y, width, height, angle, color = rectangle[i]
ax.add_patch(Rectangle((x, y), width, height, angle=angle,
edgecolor=color, fill=False))
#position of centroid
ax.plot([data.shape[1]/2, data.shape[1]/2], [0,data.shape[0]-1], lw=1,
color='black')
ax.plot([0,data.shape[1]-1], [data.shape[1]/2, data.shape[1]/2], lw=1,
color='black')
ax.annotate(instr+":"+rootname,color='white',fontsize=5,xy=(0.02, 0.95),
xycoords='axes fraction')
ax.annotate(filt,color='white',fontsize=10,xy=(0.02, 0.02),
xycoords='axes fraction')
ax.annotate(exptime,color='white',fontsize=5,xy=(0.80, 0.02),
xycoords='axes fraction')
fig.subplots_adjust(hspace=0, wspace=0, right=0.85)
cbar_ax = fig.add_axes([0.9, 0.12, 0.02, 0.75])
fig.colorbar(im, cax=cbar_ax)
if not (savename is None):
fig.suptitle(savename)
fig.savefig(plots_folder+savename+".png",bbox_inches='tight')
plt.show()
return 0
def plot_Stokes(Stokes, savename=None, plots_folder=""):
"""
Plots I/Q/U maps.
----------
Inputs:
Stokes : astropy.io.fits.hdu.hdulist.HDUList
HDUList containing I, Q, U, P, s_P, PA, s_PA (in this particular order)
for one observation.
savename : str, optional
Name of the figure the map should be saved to. If None, the map won't
be saved (only displayed).
Defaults to None.
plots_folder : str, optional
Relative (or absolute) filepath to the folder in wich the map will
be saved. Not used if savename is None.
Defaults to current folder.
"""
# Get data
stkI = Stokes[np.argmax([Stokes[i].header['datatype']=='I_stokes' for i in range(len(Stokes))])].data
stkQ = Stokes[np.argmax([Stokes[i].header['datatype']=='Q_stokes' for i in range(len(Stokes))])].data
stkU = Stokes[np.argmax([Stokes[i].header['datatype']=='U_stokes' for i in range(len(Stokes))])].data
wcs = WCS(Stokes[0]).deepcopy()
# Plot figure
fig = plt.figure(figsize=(30,10))
ax = fig.add_subplot(131, projection=wcs)
im = ax.imshow(stkI, origin='lower')
plt.colorbar(im)
ax.set(xlabel="RA", ylabel="DEC", title=r"$I_{stokes}$")
ax = fig.add_subplot(132, projection=wcs)
im = ax.imshow(stkQ, origin='lower')
plt.colorbar(im)
ax.set(xlabel="RA", ylabel="DEC", title=r"$Q_{stokes}$")
ax = fig.add_subplot(133, projection=wcs)
im = ax.imshow(stkU, origin='lower')
plt.colorbar(im)
ax.set(xlabel="RA", ylabel="DEC", title=r"$U_{stokes}$")
if not (savename is None):
fig.suptitle(savename+"_IQU")
fig.savefig(plots_folder+savename+"_IQU.png",bbox_inches='tight')
plt.show()
return 0
class crop_map(object):
"""
Class to interactively crop I_stokes map to desired Region of Interest
"""
def __init__(self, Stokes, data_mask, SNRp_cut=3., SNRi_cut=30.):
#Get data
stkI = Stokes[np.argmax([Stokes[i].header['datatype']=='I_stokes' for i in range(len(Stokes))])]
stk_cov = Stokes[np.argmax([Stokes[i].header['datatype']=='IQU_cov_matrix' for i in range(len(Stokes))])]
pol = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg_debiased' for i in range(len(Stokes))])]
pol_err = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg_err' for i in range(len(Stokes))])]
self.Stokes = Stokes
self.data_mask = data_mask
wcs = WCS(Stokes[0]).deepcopy()
#Compute SNR and apply cuts
pol.data[pol.data == 0.] = np.nan
SNRp = pol.data/pol_err.data
SNRp[np.isnan(SNRp)] = 0.
pol.data[SNRp < SNRp_cut] = np.nan
SNRi = stkI.data/np.sqrt(stk_cov.data[0,0])
SNRi[np.isnan(SNRi)] = 0.
pol.data[SNRi < SNRi_cut] = np.nan
convert_flux = Stokes[0].header['photflam']
#Plot the map
plt.rcParams.update({'font.size': 16})
self.fig = plt.figure(figsize=(15,15))
self.ax = self.fig.add_subplot(111, projection=wcs)
self.ax.set_facecolor('k')
self.fig.subplots_adjust(hspace=0, wspace=0, right=0.9)
cbar_ax = self.fig.add_axes([0.95, 0.12, 0.01, 0.75])
self.extent = [-stkI.data.shape[1]/2.,stkI.data.shape[1]/2.,-stkI.data.shape[0]/2.,stkI.data.shape[0]/2.]
self.center = [stkI.data.shape[1]/2.,stkI.data.shape[0]/2.]
vmin, vmax = 0., np.max(stkI.data[stkI.data > 0.]*convert_flux)
im = self.ax.imshow(stkI.data*convert_flux,extent=self.extent, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$F_{\lambda}$ [$ergs \cdot cm^{-2} \cdot s^{-1} \cdot \AA^{-1}$]")
levelsI = np.linspace(SNRi_cut, np.max(SNRi[SNRi > 0.]), 10)
cont = self.ax.contour(SNRi, extent=self.extent, levels=levelsI, colors='grey', linewidths=0.5)
fontprops = fm.FontProperties(size=16)
px_size = wcs.wcs.get_cdelt()[0]
px_sc = AnchoredSizeBar(self.ax.transData, 1./px_size, '1 arcsec', 3, pad=0.5, sep=5, borderpad=0.5, frameon=False, size_vertical=0.005, color='w', fontproperties=fontprops)
self.ax.add_artist(px_sc)
self.ax.set_title(
"Click and drag to crop to desired Region of Interest.\n"
"Press 'c' to toggle the selector on and off")
def onselect_crop(self, eclick, erelease) -> None:
# Obtain (xmin, xmax, ymin, ymax) values
self.RSextent = self.rect_selector.extents
self.RScenter = [self.center[i]+self.rect_selector.center[i] for i in range(2)]
# Zoom to selection
print("CROP TO : ",self.RSextent)
print("CENTER : ",self.RScenter)
#self.ax.set_xlim(self.extent[0], self.extent[1])
#self.ax.set_ylim(self.extent[2], self.extent[3])
def run(self) -> None:
self.rect_selector = RectangleSelector(self.ax, self.onselect_crop,
drawtype='box', button=[1], interactive=True)
#self.fig.canvas.mpl_connect('key_press_event', self.toggle_selector)
plt.show()
def crop(self):
Stokes_crop = copy.deepcopy(self.Stokes)
# Data sets to crop
stkI = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='I_stokes' for i in range(len(Stokes_crop))])]
stkQ = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='Q_stokes' for i in range(len(Stokes_crop))])]
stkU = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='U_stokes' for i in range(len(Stokes_crop))])]
stk_cov = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='IQU_cov_matrix' for i in range(len(Stokes_crop))])]
pol = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='Pol_deg_debiased' for i in range(len(Stokes_crop))])]
pol_err = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='Pol_deg_err' for i in range(len(Stokes_crop))])]
pang = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='Pol_ang' for i in range(len(Stokes_crop))])]
pang_err = Stokes_crop[np.argmax([Stokes_crop[i].header['datatype']=='Pol_ang_err' for i in range(len(Stokes_crop))])]
# Crop datasets
vertex = [int(self.RScenter[0]+self.RSextent[0]), int(self.RScenter[0]+self.RSextent[1]), int(self.RScenter[1]+self.RSextent[2]), int(self.RScenter[1]+self.RSextent[3])]
for dataset in [stkI, stkQ, stkU, pol, pol_err, pang, pang_err]:
dataset.data = dataset.data[vertex[2]:vertex[3], vertex[0]:vertex[1]]
data_mask = self.data_mask[vertex[2]:vertex[3], vertex[0]:vertex[1]]
new_stk_cov = np.zeros((3,3,stkI.data.shape[0],stkI.data.shape[1]))
for i in range(3):
for j in range(3):
new_stk_cov[i,j] = stk_cov.data[i,j][vertex[2]:vertex[3], vertex[0]:vertex[1]]
stk_cov.data = new_stk_cov
return Stokes_crop, data_mask
def polarization_map(Stokes, data_mask=None, rectangle=None, SNRp_cut=3., SNRi_cut=30.,
step_vec=1, savename=None, plots_folder="", display=None):
"""
Plots polarization map from Stokes HDUList.
----------
Inputs:
Stokes : astropy.io.fits.hdu.hdulist.HDUList
HDUList containing I, Q, U, P, s_P, PA, s_PA (in this particular order)
for one observation.
rectangle : numpy.ndarray, optional
Array of parameters for matplotlib.patches.Rectangle objects that will
be displayed on each output image. If None, no rectangle displayed.
Defaults to None.
SNRp_cut : float, optional
Cut that should be applied to the signal-to-noise ratio on P.
Any SNR < SNRp_cut won't be displayed.
Defaults to 3.
SNRi_cut : float, optional
Cut that should be applied to the signal-to-noise ratio on I.
Any SNR < SNRi_cut won't be displayed.
Defaults to 30. This value implies an uncertainty in P of 4.7%
step_vec : int, optional
Number of steps between each displayed polarization vector.
If step_vec = 2, every other vector will be displayed.
Defaults to 1
savename : str, optional
Name of the figure the map should be saved to. If None, the map won't
be saved (only displayed).
Defaults to None.
plots_folder : str, optional
Relative (or absolute) filepath to the folder in wich the map will
be saved. Not used if savename is None.
Defaults to current folder.
display : str, optional
Choose the map to display between intensity (default), polarization
degree ('p','pol','pol_deg') or polarization degree error ('s_p',
'pol_err','pol_deg_err').
Defaults to None (intensity).
----------
Returns:
fig, ax : matplotlib.pyplot object
The figure and ax created for interactive contour maps.
"""
#Get data
stkI = Stokes[np.argmax([Stokes[i].header['datatype']=='I_stokes' for i in range(len(Stokes))])]
stkQ = Stokes[np.argmax([Stokes[i].header['datatype']=='Q_stokes' for i in range(len(Stokes))])]
stkU = Stokes[np.argmax([Stokes[i].header['datatype']=='U_stokes' for i in range(len(Stokes))])]
stk_cov = Stokes[np.argmax([Stokes[i].header['datatype']=='IQU_cov_matrix' for i in range(len(Stokes))])]
#pol = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg' for i in range(len(Stokes))])]
pol = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg_debiased' for i in range(len(Stokes))])]
pol_err = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg_err' for i in range(len(Stokes))])]
#pol_err_Poisson = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg_err_Poisson_noise' for i in range(len(Stokes))])]
pang = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_ang' for i in range(len(Stokes))])]
pang_err = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_ang_err' for i in range(len(Stokes))])]
pivot_wav = Stokes[0].header['photplam']
convert_flux = Stokes[0].header['photflam']
wcs = WCS(Stokes[0]).deepcopy()
#Get image mask
if data_mask is None:
data_mask = np.ones(stkI.shape).astype(bool)
#Plot Stokes parameters map
if display is None:
plot_Stokes(Stokes, savename=savename, plots_folder=plots_folder)
#Compute SNR and apply cuts
pol.data[pol.data == 0.] = np.nan
SNRp = pol.data/pol_err.data
SNRp[np.isnan(SNRp)] = 0.
pol.data[SNRp < SNRp_cut] = np.nan
maskI = stk_cov.data[0,0] > 0
SNRi = np.zeros(stkI.data.shape)
SNRi[maskI] = stkI.data[maskI]/np.sqrt(stk_cov.data[0,0][maskI])
pol.data[SNRi < SNRi_cut] = np.nan
data_mask = (1.-data_mask).astype(bool)
mask = (SNRp > SNRp_cut) * (SNRi > SNRi_cut)
# Look for pixel of max polarization
if np.isfinite(pol.data).any():
p_max = np.max(pol.data[np.isfinite(pol.data)])
x_max, y_max = np.unravel_index(np.argmax(pol.data==p_max),pol.data.shape)
else:
print("No pixel with polarization information above requested SNR.")
#Plot the map
plt.rcParams.update({'font.size': 16})
fig = plt.figure(figsize=(15,15))
ax = fig.add_subplot(111, projection=wcs)
ax.set_facecolor('k')
fig.subplots_adjust(hspace=0, wspace=0, right=0.9)
cbar_ax = fig.add_axes([0.95, 0.12, 0.01, 0.75])
if display is None:
# If no display selected, show intensity map
vmin, vmax = 0., np.max(stkI.data[stkI.data > 0.]*convert_flux)
im = ax.imshow(stkI.data*convert_flux, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$F_{\lambda}$ [$ergs \cdot cm^{-2} \cdot s^{-1} \cdot \AA^{-1}$]")
levelsI = np.linspace(SNRi_cut, np.max(SNRi[SNRi > 0.]), 10)
cont = ax.contour(SNRi, levels=levelsI, colors='grey', linewidths=0.5)
elif display.lower() in ['pol_flux']:
# Display polarisation flux
pf_mask = (stkI.data > 0.) * (pol.data > 0.)
vmin, vmax = 0., np.max(stkI.data[pf_mask]*convert_flux*pol.data[pf_mask])
im = ax.imshow(stkI.data*convert_flux*pol.data, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$F_{\lambda} \cdot P$ [$ergs \cdot cm^{-2} \cdot s^{-1} \cdot \AA^{-1}$]")
elif display.lower() in ['p','pol','pol_deg']:
# Display polarization degree map
vmin, vmax = 0., 100.
im = ax.imshow(pol.data*100., vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$P$ [%]")
elif display.lower() in ['s_p','pol_err','pol_deg_err']:
# Display polarization degree error map
vmin, vmax = 0., 10.
p_err = pol_err.data.copy()
p_err[p_err > vmax/100.] = np.nan
im = ax.imshow(p_err*100., vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$\sigma_P$ [%]")
elif display.lower() in ['s_i','i_err']:
# Display intensity error map
vmin, vmax = 0., np.max(np.sqrt(stk_cov.data[0,0][stk_cov.data[0,0] > 0.])*convert_flux)
im = ax.imshow(np.sqrt(stk_cov.data[0,0])*convert_flux, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$\sigma_I$ [$ergs \cdot cm^{-2} \cdot s^{-1} \cdot \AA^{-1}$]")
elif display.lower() in ['snr','snri']:
# Display I_stokes signal-to-noise map
vmin, vmax = 0., np.max(SNRi[SNRi > 0.])
im = ax.imshow(SNRi, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$I_{Stokes}/\sigma_{I}$")
levelsI = np.linspace(SNRi_cut, np.max(SNRi[SNRi > 0.]), 10)
cont = ax.contour(SNRi, levels=levelsI, colors='grey', linewidths=0.5)
elif display.lower() in ['snrp']:
# Display polarization degree signal-to-noise map
vmin, vmax = SNRp_cut, np.max(SNRp[SNRp > 0.])
im = ax.imshow(SNRp, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$P/\sigma_{P}$")
levelsP = np.linspace(SNRp_cut, np.max(SNRp[SNRp > 0.]), 10)
cont = ax.contour(SNRp, levels=levelsP, colors='grey', linewidths=0.5)
else:
# Defaults to intensity map
vmin, vmax = 0., np.max(stkI.data[stkI.data > 0.]*convert_flux)
im = ax.imshow(stkI.data*convert_flux, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
cbar = plt.colorbar(im, cax=cbar_ax, label=r"$F_{\lambda}$ [$ergs \cdot cm^{-2} \cdot s^{-1} \cdot \AA$]")
levelsI = np.linspace(SNRi_cut, SNRi.max(), 10)
cont = ax.contour(SNRi, levels=levelsI, colors='grey', linewidths=0.5)
fontprops = fm.FontProperties(size=16)
px_size = wcs.wcs.get_cdelt()[0]*3600.
px_sc = AnchoredSizeBar(ax.transData, 1./px_size, '1 arcsec', 3, pad=0.5, sep=5, borderpad=0.5, frameon=False, size_vertical=0.005, color='w', fontproperties=fontprops)
ax.add_artist(px_sc)
#pol.data[np.isfinite(pol.data)] = 1./2.
X, Y = np.meshgrid(np.linspace(0,stkI.data.shape[0],stkI.data.shape[0]), np.linspace(0,stkI.data.shape[1],stkI.data.shape[1]))
U, V = pol.data*np.cos(np.pi/2.+pang.data*np.pi/180.), pol.data*np.sin(np.pi/2.+pang.data*np.pi/180.)
Q = ax.quiver(X[::step_vec,::step_vec],Y[::step_vec,::step_vec],U[::step_vec,::step_vec],V[::step_vec,::step_vec],units='xy',angles='uv',scale=0.5,scale_units='xy',pivot='mid',headwidth=0.,headlength=0.,headaxislength=0.,width=0.1,color='w')
pol_sc = AnchoredSizeBar(ax.transData, 2., r"$P$= 100 %", 4, pad=0.5, sep=5, borderpad=0.5, frameon=False, size_vertical=0.005, color='w', fontproperties=fontprops)
ax.add_artist(pol_sc)
north_dir = AnchoredDirectionArrows(ax.transAxes, "E", "N", length=-0.08, fontsize=0.03, loc=1, aspect_ratio=-1, sep_y=0.01, sep_x=0.01, angle=-Stokes[0].header['orientat'], color='w', arrow_props={'ec': 'w', 'fc': 'w', 'alpha': 1,'lw': 2})
ax.add_artist(north_dir)
# Display instrument FOV
if not(rectangle is None):
x, y, width, height, angle, color = rectangle
x, y = np.array([x, y])- np.array(stkI.data.shape)/2.
ax.add_patch(Rectangle((x, y), width, height, angle=angle,
edgecolor=color, fill=False))
# Compute integrated parameters and associated errors for pixels in the cut
n_pix = mask.size
I_int = stkI.data[mask].sum()
Q_int = stkQ.data[mask].sum()
U_int = stkU.data[mask].sum()
I_int_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[0,0][mask]))
Q_int_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[1,1][mask]))
U_int_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[2,2][mask]))
IQ_int_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[0,1][mask]**2))
IU_int_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[0,2][mask]**2))
QU_int_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[1,2][mask]**2))
P_int = np.sqrt(Q_int**2+U_int**2)/I_int
P_int_err = (1./I_int)*np.sqrt((Q_int**2*Q_int_err**2 + U_int**2*U_int_err**2 + 2.*Q_int*U_int*QU_int_err)/(Q_int**2 + U_int**2) + ((Q_int/I_int)**2 + (U_int/I_int)**2)*I_int_err**2 - 2.*(Q_int/I_int)*IQ_int_err - 2.*(U_int/I_int)*IU_int_err)
PA_int = princ_angle((90./np.pi)*np.arctan2(U_int,Q_int))
PA_int_err = (90./(np.pi*(Q_int**2 + U_int**2)))*np.sqrt(U_int**2*Q_int_err**2 + Q_int**2*U_int_err**2 - 2.*Q_int*U_int*QU_int_err)
# Compute integrated parameters and associated errors for all pixels
n_pix = stkI.data[data_mask].size
I_diluted = stkI.data[data_mask].sum()
Q_diluted = stkQ.data[data_mask].sum()
U_diluted = stkU.data[data_mask].sum()
I_diluted_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[0,0][data_mask]))
Q_diluted_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[1,1][data_mask]))
U_diluted_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[2,2][data_mask]))
IQ_diluted_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[0,1][data_mask]**2))
IU_diluted_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[0,2][data_mask]**2))
QU_diluted_err = np.sqrt(n_pix)*np.sqrt(np.sum(stk_cov.data[1,2][data_mask]**2))
P_diluted = np.sqrt(Q_diluted**2+U_diluted**2)/I_diluted
P_diluted_err = (1./I_diluted)*np.sqrt((Q_diluted**2*Q_diluted_err**2 + U_diluted**2*U_diluted_err**2 + 2.*Q_diluted*U_diluted*QU_diluted_err)/(Q_diluted**2 + U_diluted**2) + ((Q_diluted/I_diluted)**2 + (U_diluted/I_diluted)**2)*I_diluted_err**2 - 2.*(Q_diluted/I_diluted)*IQ_diluted_err - 2.*(U_diluted/I_diluted)*IU_diluted_err)
#P_diluted_err = np.sqrt(2/n_pix)*100.
PA_diluted = princ_angle((90./np.pi)*np.arctan2(U_diluted,Q_diluted))
PA_diluted_err = (90./(np.pi*(Q_diluted**2 + U_diluted**2)))*np.sqrt(U_diluted**2*Q_diluted_err**2 + Q_diluted**2*U_diluted_err**2 - 2.*Q_diluted*U_diluted*QU_diluted_err)
#PA_diluted_err = P_diluted_err/(2.*P_diluted)*180./np.pi
ax.annotate(r"$F_{{\lambda}}^{{int}}$({0:.0f} $\AA$) = {1} $ergs \cdot cm^{{-2}} \cdot s^{{-1}} \cdot \AA^{{-1}}$".format(pivot_wav,sci_not(I_diluted*convert_flux,I_diluted_err*convert_flux,2))+"\n"+r"$P^{{int}}$ = {0:.1f} $\pm$ {1:.1f} %".format(P_diluted*100.,P_diluted_err*100.)+"\n"+r"$\theta_{{P}}^{{int}}$ = {0:.1f} $\pm$ {1:.1f} °".format(PA_diluted,PA_diluted_err), color='white', fontsize=16, xy=(0.01, 0.92), xycoords='axes fraction')
ax.coords.grid(True, color='white', ls='dotted', alpha=0.5)
ax.coords[0].set_axislabel('Right Ascension (J2000)')
ax.coords[0].set_axislabel_position('t')
ax.coords[0].set_ticklabel_position('t')
ax.coords[1].set_axislabel('Declination (J2000)')
ax.coords[1].set_axislabel_position('l')
ax.coords[1].set_ticklabel_position('l')
ax.axis('equal')
if not savename is None:
#fig.suptitle(savename)
fig.savefig(plots_folder+savename+".png",bbox_inches='tight',dpi=200)
plt.show()
return fig, ax
class align_maps(object):
"""
Class to interactively align maps with different WCS.
"""
def __init__(self, Stokes, other_map, SNRp_cut=3., SNRi_cut=30.):
#Get data
stkI = Stokes[np.argmax([Stokes[i].header['datatype']=='I_stokes' for i in range(len(Stokes))])]
stk_cov = Stokes[np.argmax([Stokes[i].header['datatype']=='IQU_cov_matrix' for i in range(len(Stokes))])]
pol = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg_debiased' for i in range(len(Stokes))])]
pol_err = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_deg_err' for i in range(len(Stokes))])]
pang = Stokes[np.argmax([Stokes[i].header['datatype']=='Pol_ang' for i in range(len(Stokes))])]
wcs1 = WCS(Stokes[0]).deepcopy()
convert_flux = Stokes[0].header['photflam']
wcs2 = WCS(other_map).deepcopy()
#Compute SNR and apply cuts
pol.data[pol.data == 0.] = np.nan
SNRp = pol.data/pol_err.data
SNRp[np.isnan(SNRp)] = 0.
pol.data[SNRp < SNRp_cut] = np.nan
SNRi = stkI.data/np.sqrt(stk_cov.data[0,0])
SNRi[np.isnan(SNRi)] = 0.
pol.data[SNRi < SNRi_cut] = np.nan
plt.rcParams.update({'font.size': 16})
self.fig = plt.figure(figsize=(25,15))
#Plot the UV map
self.ax1 = self.fig.add_subplot(121, projection=wcs1)
self.ax1.set_facecolor('k')
vmin, vmax = 0., np.max(stkI.data[stkI.data > 0.]*convert_flux)
im1 = self.ax1.imshow(stkI.data*convert_flux, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
fontprops = fm.FontProperties(size=16)
px_size = wcs1.wcs.get_cdelt()[0]*3600.
px_sc = AnchoredSizeBar(self.ax1.transData, 1./px_size, '1 arcsec', 3, pad=0.5, sep=5, borderpad=0.5, frameon=False, size_vertical=0.005, color='w', fontproperties=fontprops)
self.ax1.add_artist(px_sc)
north_dir1 = AnchoredDirectionArrows(self.ax1.transAxes, "E", "N", length=-0.08, fontsize=0.03, loc=1, aspect_ratio=-1, sep_y=0.01, sep_x=0.01, angle=-Stokes[0].header['orientat'], color='w', arrow_props={'ec': 'w', 'fc': 'w', 'alpha': 1,'lw': 2})
self.ax1.add_artist(north_dir1)
pol.data[np.isfinite(pol.data)] = 1./2.
step_vec = 1
X, Y = np.meshgrid(np.linspace(0,stkI.data.shape[0],stkI.data.shape[0]), np.linspace(0,stkI.data.shape[1],stkI.data.shape[1]))
U, V = pol.data*np.cos(np.pi/2.+pang.data*np.pi/180.), pol.data*np.sin(np.pi/2.+pang.data*np.pi/180.)
Q = self.ax1.quiver(X[::step_vec,::step_vec],Y[::step_vec,::step_vec],U[::step_vec,::step_vec],V[::step_vec,::step_vec],units='xy',angles='uv',scale=0.5,scale_units='xy',pivot='mid',headwidth=0.,headlength=0.,headaxislength=0.,width=0.1,color='w')
self.ax1.set_title("Click on selected point of reference.")
#Plot the other map
self.ax2 = self.fig.add_subplot(122, projection=wcs2)
self.ax2.set_facecolor('k')
vmin, vmax = 0., np.max(other_map.data[other_map.data > 0.])
im2 = self.ax2.imshow(other_map.data, vmin=vmin, vmax=vmax, aspect='auto', cmap='inferno', alpha=1.)
fontprops = fm.FontProperties(size=16)
px_size = wcs2.wcs.get_cdelt()[0]*3600.
px_sc = AnchoredSizeBar(self.ax2.transData, 1./px_size, '1 arcsec', 3, pad=0.5, sep=5, borderpad=0.5, frameon=False, size_vertical=0.005, color='w', fontproperties=fontprops)
self.ax2.add_artist(px_sc)
self.ax2.set_title("Click on selected point of reference.")