def plot_norm(self,
stretch='linear',
power=1.0,
asinh_a=0.1,
min_cut=None,
max_cut=None,
min_percent=None,
max_percent=None,
percent=None,
clip=True):
"""Create a matplotlib norm object for plotting.
This is a copy of this function that will be available in Astropy 1.3:
`astropy.visualization.mpl_normalize.simple_norm`
See the parameter description there!
Examples
--------
>>> image = SkyImage()
>>> norm = image.plot_norm(stretch='sqrt', max_percent=99)
>>> image.plot(norm=norm)
"""
import astropy.visualization as v
from astropy.visualization.mpl_normalize import ImageNormalize
if percent is not None:
interval = v.PercentileInterval(percent)
elif min_percent is not None or max_percent is not None:
interval = v.AsymmetricPercentileInterval(min_percent or 0.,
max_percent or 100.)
elif min_cut is not None or max_cut is not None:
interval = v.ManualInterval(min_cut, max_cut)
else:
interval = v.MinMaxInterval()
if stretch == 'linear':
stretch = v.LinearStretch()
elif stretch == 'sqrt':
stretch = v.SqrtStretch()
elif stretch == 'power':
stretch = v.PowerStretch(power)
elif stretch == 'log':
stretch = v.LogStretch()
elif stretch == 'asinh':
stretch = v.AsinhStretch(asinh_a)
else:
raise ValueError('Unknown stretch: {0}.'.format(stretch))
vmin, vmax = interval.get_limits(self.data)
return ImageNormalize(vmin=vmin, vmax=vmax, stretch=stretch, clip=clip)
def scale_rgb(red, green, blue, stretch_coeff, pmin=0, pmax=98.):
""" Perform interval and stretch for RGB
Parameters
----------
red : CCDData object
Red filter image data, parsed with load_image
green : CCDData object
Green filter image data, parsed with load_image
blue : CCDData object
Blue filter image data, parsed with load_image
stretch_coeff : tuple, (1,3)
Power-law stretch coefficients for (red, green, blue)
filters respectively.
pmin : float, default = 0
The lower percentile below which to ignore pixels. Passed to
AsymmetricPercentileInterval function.
pmax : float, default = 98
The upper percentile above which to ignore pixels. Passed to
AsymmetricPercentileInterval function.
Returns
-------
rgb : np.array, N x N x 3
"""
r_stretch = vis.stretch.PowerStretch(stretch_coeff[0])
g_stretch = vis.stretch.PowerStretch(stretch_coeff[1])
b_stretch = vis.stretch.PowerStretch(stretch_coeff[2])
interval = vis.AsymmetricPercentileInterval(pmin, pmax)
rgb = np.array([
r_stretch(interval(red)),
g_stretch(interval(green)),
b_stretch(interval(blue))
]).T
return rgb
def get_im_interval(pmin=10, pmax=99.9, vmin=None, vmax=None):
''' Returns an interval, to feed the ImageNormalize routine from Astropy.
:param pmin: lower-limit percentile
:type pmin: float
:param pmax: upper-limit percentile
:type pmax: float
:param vmin: absolute lower limit
:type vmin: float
:param vmax: absolute upper limit
:type vmax: float
:return: an :class:`astropy.visualization.interval` thingy ...
:rtype: :class:`astropy.visualization.interval`
.. note:: Specifying *both* vmin and vmax will override pmin and pmax.
'''
if vmin is not None and vmax is not None:
return astrovis.ManualInterval(vmin, vmax)
return astrovis.AsymmetricPercentileInterval(pmin, pmax)
def show_image(image,
percl=99,
percu=None,
is_mask=False,
figsize=(6, 10),
cmap='viridis',
log=False,
show_colorbar=True,
show_ticks=True,
fig=None,
ax=None,
input_ratio=None):
"""
Show an image in matplotlib with some basic astronomically-appropriat stretching.
Parameters
----------
image
The image to show
percl : number
The percentile for the lower edge of the stretch (or both edges if ``percu`` is None)
percu : number or None
The percentile for the upper edge of the stretch (or None to use ``percl`` for both)
figsize : 2-tuple
The size of the matplotlib figure in inches
"""
if percu is None:
percu = percl
percl = 100 - percl
if (fig is None and ax is not None) or (fig is not None and ax is None):
raise ValueError('Must provide both "fig" and "ax" '
'if you provide one of them')
elif fig is None and ax is None:
fig, ax = plt.subplots(1, 1, figsize=figsize)
if figsize is not None:
# Rescale the fig size to match the image dimensions, roughly
image_aspect_ratio = image.shape[0] / image.shape[1]
figsize = (max(figsize) * image_aspect_ratio, max(figsize))
print(figsize)
# To preserve details we should *really* downsample correctly and
# not rely on matplotlib to do it correctly for us (it won't).
# So, calculate the size of the figure in pixels, block_reduce to
# roughly that,and display the block reduced image.
# Thanks, https://stackoverflow.com/questions/29702424/how-to-get-matplotlib-figure-size
fig_size_pix = fig.get_size_inches() * fig.dpi
ratio = (image.shape // fig_size_pix).max()
if ratio < 1:
ratio = 1
ratio = input_ratio or ratio
# Divide by the square of the ratio to keep the flux the same in the
# reduced image
reduced_data = block_reduce(image, ratio) / ratio**2
# Of course, now that we have downsampled, the axis limits are changed to
# match the smaller image size. Setting the extent will do the trick to
# change the axis display back to showing the actual extent of the image.
extent = [0, image.shape[1], 0, image.shape[0]]
if log:
stretch = aviz.LogStretch()
else:
stretch = aviz.LinearStretch()
norm = aviz.ImageNormalize(reduced_data,
interval=aviz.AsymmetricPercentileInterval(
percl, percu),
stretch=stretch)
if is_mask:
# The image is a mask in which pixels are zero or one. Set the image scale
# limits appropriately.
scale_args = dict(vmin=0, vmax=1)
else:
scale_args = dict(norm=norm)
im = ax.imshow(reduced_data,
origin='lower',
cmap=cmap,
extent=extent,
aspect='equal',
**scale_args)
if show_colorbar:
# I haven't a clue why the fraction and pad arguments below work to make
# the colorbar the same height as the image, but they do....unless the image
# is wider than it is tall. Sticking with this for now anyway...
# Thanks: https://stackoverflow.com/a/26720422/3486425
fig.colorbar(im, ax=ax, fraction=0.046, pad=0.04, format='%2.0f')
# In case someone in the future wants to improve this:
# https://joseph-long.com/writing/colorbars/
# https://stackoverflow.com/a/33505522/3486425
# https://matplotlib.org/mpl_toolkits/axes_grid/users/overview.html#colorbar-whose-height-or-width-in-sync-with-the-master-axes
if not show_ticks:
ax.tick_params(labelbottom=False,
labelleft=False,
labelright=False,
labeltop=False)
def plot_image(image,
ax=None,
scale='log',
cmap=None,
origin='lower',
xlabel=None,
ylabel=None,
cbar=None,
clabel='Flux ($e^{-}s^{-1}$)',
cbar_ticks=None,
cbar_ticklabels=None,
cbar_pad=None,
cbar_size='5%',
title=None,
percentile=95.0,
vmin=None,
vmax=None,
offset_axes=None,
color_bad='k',
**kwargs):
"""
Utility function to plot a 2D image.
Parameters:
image (2d array): Image data.
ax (matplotlib.pyplot.axes, optional): Axes in which to plot.
Default (None) is to use current active axes.
scale (str or :py:class:`astropy.visualization.ImageNormalize` object, optional):
Normalization used to stretch the colormap.
Options: ``'linear'``, ``'sqrt'``, ``'log'``, ``'asinh'``, ``'histeq'``, ``'sinh'``
and ``'squared'``.
Can also be a :py:class:`astropy.visualization.ImageNormalize` object.
Default is ``'log'``.
origin (str, optional): The origin of the coordinate system.
xlabel (str, optional): Label for the x-axis.
ylabel (str, optional): Label for the y-axis.
cbar (string, optional): Location of color bar.
Choises are ``'right'``, ``'left'``, ``'top'``, ``'bottom'``.
Default is not to create colorbar.
clabel (str, optional): Label for the color bar.
cbar_size (float, optional): Fractional size of colorbar compared to axes. Default=0.03.
cbar_pad (float, optional): Padding between axes and colorbar.
title (str or None, optional): Title for the plot.
percentile (float, optional): The fraction of pixels to keep in color-trim.
If single float given, the same fraction of pixels is eliminated from both ends.
If tuple of two floats is given, the two are used as the percentiles.
Default=95.
cmap (matplotlib colormap, optional): Colormap to use. Default is the ``Blues`` colormap.
vmin (float, optional): Lower limit to use for colormap.
vmax (float, optional): Upper limit to use for colormap.
color_bad (str, optional): Color to apply to bad pixels (NaN). Default is black.
kwargs (dict, optional): Keyword arguments to be passed to :py:func:`matplotlib.pyplot.imshow`.
Returns:
:py:class:`matplotlib.image.AxesImage`: Image from returned
by :py:func:`matplotlib.pyplot.imshow`.
.. codeauthor:: Rasmus Handberg <*****@*****.**>
"""
logger = logging.getLogger(__name__)
# Backward compatible settings:
make_cbar = kwargs.pop('make_cbar', None)
if make_cbar:
raise FutureWarning("'make_cbar' is deprecated. Use 'cbar' instead.")
if not cbar:
cbar = make_cbar
# Special treatment for boolean arrays:
if isinstance(image, np.ndarray) and image.dtype == 'bool':
if vmin is None: vmin = 0
if vmax is None: vmax = 1
if cbar_ticks is None: cbar_ticks = [0, 1]
if cbar_ticklabels is None: cbar_ticklabels = ['False', 'True']
# Calculate limits of color scaling:
interval = None
if vmin is None or vmax is None:
if allnan(image):
logger.warning("Image is all NaN")
vmin = 0
vmax = 1
if cbar_ticks is None:
cbar_ticks = []
if cbar_ticklabels is None:
cbar_ticklabels = []
elif isinstance(percentile, (list, tuple, np.ndarray)):
interval = viz.AsymmetricPercentileInterval(
percentile[0], percentile[1])
else:
interval = viz.PercentileInterval(percentile)
# Create ImageNormalize object with extracted limits:
if scale in ('log', 'linear', 'sqrt', 'asinh', 'histeq', 'sinh',
'squared'):
if scale == 'log':
stretch = viz.LogStretch()
elif scale == 'linear':
stretch = viz.LinearStretch()
elif scale == 'sqrt':
stretch = viz.SqrtStretch()
elif scale == 'asinh':
stretch = viz.AsinhStretch()
elif scale == 'histeq':
stretch = viz.HistEqStretch(image[np.isfinite(image)])
elif scale == 'sinh':
stretch = viz.SinhStretch()
elif scale == 'squared':
stretch = viz.SquaredStretch()
# Create ImageNormalize object. Very important to use clip=False if the image contains
# NaNs, otherwise NaN points will not be plotted correctly.
norm = viz.ImageNormalize(data=image[np.isfinite(image)],
interval=interval,
vmin=vmin,
vmax=vmax,
stretch=stretch,
clip=not anynan(image))
elif isinstance(scale, (viz.ImageNormalize, matplotlib.colors.Normalize)):
norm = scale
else:
raise ValueError("scale {} is not available.".format(scale))
if offset_axes:
extent = (offset_axes[0] - 0.5, offset_axes[0] + image.shape[1] - 0.5,
offset_axes[1] - 0.5, offset_axes[1] + image.shape[0] - 0.5)
else:
extent = (-0.5, image.shape[1] - 0.5, -0.5, image.shape[0] - 0.5)
if ax is None:
ax = plt.gca()
# Set up the colormap to use. If a bad color is defined,
# add it to the colormap:
if cmap is None:
cmap = copy.copy(plt.get_cmap('Blues'))
elif isinstance(cmap, str):
cmap = copy.copy(plt.get_cmap(cmap))
if color_bad:
cmap.set_bad(color_bad, 1.0)
# Plotting the image using all the settings set above:
im = ax.imshow(image,
cmap=cmap,
norm=norm,
origin=origin,
extent=extent,
interpolation='nearest',
**kwargs)
if xlabel is not None:
ax.set_xlabel(xlabel)
if ylabel is not None:
ax.set_ylabel(ylabel)
if title is not None:
ax.set_title(title)
ax.set_xlim([extent[0], extent[1]])
ax.set_ylim([extent[2], extent[3]])
if cbar:
colorbar(im,
ax=ax,
loc=cbar,
size=cbar_size,
pad=cbar_pad,
label=clabel,
ticks=cbar_ticks,
ticklabels=cbar_ticklabels)
# Settings for ticks:
integer_locator = MaxNLocator(nbins=10, integer=True)
ax.xaxis.set_major_locator(integer_locator)
ax.xaxis.set_minor_locator(integer_locator)
ax.yaxis.set_major_locator(integer_locator)
ax.yaxis.set_minor_locator(integer_locator)
ax.tick_params(which='both', direction='out', pad=5)
ax.xaxis.tick_bottom()
ax.yaxis.tick_left()
return im
def plotDirectCutouts(self,
savePath=None,
colourMap='viridis',
gridSpecs=None):
if self.directCutouts is not None:
if gridSpecs is None:
mplplot.figure(figsize=(10, 5))
for stampIndex, (grism, cutoutData) in enumerate(
self.directCutouts.items()):
if gridSpecs is None:
subplotAxes = mplplot.subplot(2, 1, stampIndex + 1)
else:
subplotAxes = mplplot.subplot(gridSpecs[stampIndex])
if cutoutData is None:
subplotAxes.text(
0.5,
0.5,
'Field {}, Object {}:\nNO DATA AVAILABLE.'.format(
self.targetPar, self.targetObject),
horizontalalignment='center',
fontsize='large',
transform=subplotAxes.transAxes)
continue
if np.all(cutoutData < 0):
subplotAxes.text(
0.5,
0.5,
'Field {}, Object {}:\nNO NONZERO DATA AVAILABLE.'.
format(self.targetPar, self.targetObject),
horizontalalignment='center',
fontsize='large',
transform=subplotAxes.transAxes)
continue
norm = astromplnorm.ImageNormalize(
cutoutData,
interval=astrovis.AsymmetricPercentileInterval(0, 99.5),
stretch=astrovis.LinearStretch(),
clip=True)
mplplot.imshow(cutoutData,
origin='lower',
interpolation='nearest',
cmap=colourMap,
norm=norm)
mplplot.xlabel('X (pixels)')
mplplot.ylabel('Y (pixels)')
mplplot.title(
'Field {}, Object {}:\nDirect cutout for F{} (G{})'.format(
self.targetPar, self.targetObject,
self.getDirectFilterForGrism(grism), grism))
arcsecYAxis = subplotAxes.twinx()
arcsecYAxis.set_ylim(*(np.array(subplotAxes.get_ylim()) -
0.5 * np.sum(subplotAxes.get_ylim())) *
self.directHdus[grism][1]['IDCSCALE'])
print(
subplotAxes.get_ylim(), np.array(subplotAxes.get_ylim()),
np.array(subplotAxes.get_ylim()) *
self.directHdus[grism][1]['IDCSCALE'],
*np.array(subplotAxes.get_ylim()) *
self.directHdus[grism][1]['IDCSCALE'])
arcsecYAxis.set_ylabel('$\Delta Y$ (arcsec)')
mplplot.grid(color='white', ls='solid')
try:
mplplot.tight_layout()
except ValueError as e:
print(
'Error attempting tight_layout for: Field {}, Object {} ({})'
.format(self.targetPar, self.targetObject, e))
return
if savePath is not None:
mplplot.savefig(savePath, dpi=300, bbox_inches='tight')
mplplot.close()
else:
print(
'The loadDirectCutouts(...) method must be called before direct cutouts can be plotted.'
)
def set_normalization(self,
stretch=None,
interval=None,
stretchkwargs={},
intervalkwargs={},
perm_linear=None):
if stretch is None:
if self.stretch is None:
stretch = 'linear'
else:
stretch = self.stretch
if isinstance(stretch, str):
print(stretch,
' '.join([f'{k}={v}' for k, v in stretchkwargs.items()]))
if self.data is None: #can not calculate objects yet
self.stretch_kwargs = stretchkwargs
else:
kwargs = self.prepare_kwargs(
self.stretch_kws_defaults[stretch], self.stretch_kwargs,
stretchkwargs)
if perm_linear is not None:
perm_linear_kwargs = self.prepare_kwargs(
self.stretch_kws_defaults['linear'], perm_linear)
print(
'linear', ' '.join([
f'{k}={v}' for k, v in perm_linear_kwargs.items()
]))
if stretch == 'asinh': # arg: a=0.1
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.AsinhStretch(**kwargs))
elif stretch == 'contrastbias': # args: contrast, bias
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.ContrastBiasStretch(**kwargs))
elif stretch == 'histogram':
stretch = vis.CompositeStretch(
vis.HistEqStretch(self.data, **kwargs),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'log': # args: a=1000.0
stretch = vis.CompositeStretch(
vis.LogStretch(**kwargs),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'powerdist': # args: a=1000.0
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.PowerDistStretch(**kwargs))
elif stretch == 'power': # args: a
stretch = vis.CompositeStretch(
vis.PowerStretch(**kwargs),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'sinh': # args: a=0.33
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.SinhStretch(**kwargs))
elif stretch == 'sqrt':
stretch = vis.CompositeStretch(
vis.SqrtStretch(),
vis.LinearStretch(**perm_linear_kwargs))
elif stretch == 'square':
stretch = vis.CompositeStretch(
vis.LinearStretch(**perm_linear_kwargs),
vis.SquaredStretch())
else:
raise ValueError('Unknown stretch:' + stretch)
else:
if stretch == 'linear': # args: slope=1, intercept=0
stretch = vis.LinearStretch(**kwargs)
else:
raise ValueError('Unknown stretch:' + stretch)
self.stretch = stretch
if interval is None:
if self.interval is None:
interval = 'zscale'
else:
interval = self.interval
if isinstance(interval, str):
print(interval,
' '.join([f'{k}={v}' for k, v in intervalkwargs.items()]))
kwargs = self.prepare_kwargs(self.interval_kws_defaults[interval],
self.interval_kwargs, intervalkwargs)
if self.data is None:
self.interval_kwargs = intervalkwargs
else:
if interval == 'minmax':
interval = vis.MinMaxInterval()
elif interval == 'manual': # args: vmin, vmax
interval = vis.ManualInterval(**kwargs)
elif interval == 'percentile': # args: percentile, n_samples
interval = vis.PercentileInterval(**kwargs)
elif interval == 'asymetric': # args: lower_percentile, upper_percentile, n_samples
interval = vis.AsymmetricPercentileInterval(**kwargs)
elif interval == 'zscale': # args: nsamples=1000, contrast=0.25, max_reject=0.5, min_npixels=5, krej=2.5, max_iterations=5
interval = vis.ZScaleInterval(**kwargs)
else:
raise ValueError('Unknown interval:' + interval)
self.interval = interval
if self.img is not None:
self.img.set_norm(
vis.ImageNormalize(self.data,
interval=self.interval,
stretch=self.stretch,
clip=True))
def show_image(image,
percl=99,
percu=None,
figsize=(6, 10),
cmap='viridis',
log=False):
"""
Show an image in matplotlib with some basic astronomically-appropriat stretching.
Parameters
----------
image
The image to show
percl : number
The percentile for the lower edge of the stretch (or both edges if ``percu`` is None)
percu : number or None
The percentile for the upper edge of the stretch (or None to use ``percl`` for both)
figsize : 2-tuple
The size of the matplotlib figure in inches
"""
if percu is None:
percu = percl
percl = 100 - percl
if figsize is not None:
# Rescale the fig size to match the image dimensions, roughly
image_aspect_ratio = image.shape[0] / image.shape[1]
figsize = (max(figsize) * image_aspect_ratio, max(figsize))
fig, ax = plt.subplots(1, 1, figsize=figsize)
# To preserve details we should *really* downsample correctly and not rely on
# matplotlib to do it correctly for us (it won't).
# So, calculate the size of the figure in pixels, block_reduce to roughly that,
# and display the block reduced image.
# Thanks, https://stackoverflow.com/questions/29702424/how-to-get-matplotlib-figure-size
fig_size_pix = fig.get_size_inches() * fig.dpi
ratio = (image.shape // fig_size_pix).max()
if ratio < 1:
ratio = 1
# Divide by the square of the ratio to keep the flux the same in the reduced image
reduced_data = block_reduce(image, ratio) / ratio**2
# Of course, now that we have downsampled, the axis limits are changed to match
# the smaller image size. Setting the extent will do the trick to change the axis display
# back to showing the actual extent of the image.
extent = [0, image.shape[1], 0, image.shape[0]]
if log:
stretch = aviz.LogStretch()
else:
stretch = aviz.LinearStretch()
norm = aviz.ImageNormalize(reduced_data,
interval=aviz.AsymmetricPercentileInterval(
percl, percu),
stretch=stretch)
plt.colorbar(
ax.imshow(reduced_data,
norm=norm,
origin='lower',
cmap=cmap,
extent=extent))
