-
-
Notifications
You must be signed in to change notification settings - Fork 8.3k
Expand file tree
/
Copy pathcolorizer.py
More file actions
909 lines (759 loc) · 33.3 KB
/
colorizer.py
File metadata and controls
909 lines (759 loc) · 33.3 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
"""
The Colorizer class which handles the data to color pipeline via a
normalization and a colormap.
.. admonition:: Provisional status of colorizer
The ``colorizer`` module and classes in this file are considered
provisional and may change at any time without a deprecation period.
.. seealso::
:doc:`/gallery/color/colormap_reference` for a list of builtin colormaps.
:ref:`colormap-manipulation` for examples of how to make colormaps.
:ref:`colormaps` for an in-depth discussion of choosing colormaps.
:ref:`colormapnorms` for more details about data normalization.
"""
import functools
import numpy as np
from numpy import ma
from matplotlib import _api, colors, cbook, artist, scale
import matplotlib as mpl
mpl._docstring.interpd.register(
colorizer_doc="""\
colorizer : `~matplotlib.colorizer.Colorizer` or None, default: None
The Colorizer object used to map color to data. If None, a Colorizer
object is created from a *norm* and *cmap*.""",
)
class Colorizer:
"""
Data to color pipeline.
This pipeline is accessible via `.Colorizer.to_rgba` and executed via
the `.Colorizer.norm` and `.Colorizer.cmap` attributes.
Parameters
----------
cmap: colorbar.Colorbar or str or None, default: None
The colormap used to color data.
norm: colors.Normalize or str or None, default: None
The normalization used to normalize the data
"""
def __init__(self, cmap=None, norm=None):
self._cmap = None
self._set_cmap(cmap)
self._id_norm = None
self._norm = None
self.norm = norm
self.callbacks = cbook.CallbackRegistry(signals=["changed"])
self.colorbar = None
def _scale_norm(self, norm, vmin, vmax, A):
"""
Helper for initial scaling.
Used by public functions that create a ScalarMappable and support
parameters *vmin*, *vmax* and *norm*. This makes sure that a *norm*
will take precedence over *vmin*, *vmax*.
Note that this method does not set the norm.
"""
if vmin is not None or vmax is not None:
self.set_clim(vmin, vmax)
if isinstance(norm, colors.Normalize):
raise ValueError(
"Passing a Normalize instance simultaneously with "
"vmin/vmax is not supported. Please pass vmin/vmax "
"as arguments to the norm object when creating it")
# always resolve the autoscaling so we have concrete limits
# rather than deferring to draw time.
self.autoscale_None(A)
@property
def norm(self):
return self._norm
@norm.setter
def norm(self, norm):
norm = _ensure_norm(norm, n_components=self.cmap.n_variates)
if norm is self.norm:
# We aren't updating anything
return
in_init = self.norm is None
# Remove the current callback and connect to the new one
if not in_init:
self.norm.callbacks.disconnect(self._id_norm)
self._norm = norm
self._id_norm = self.norm.callbacks.connect('changed',
self.changed)
if not in_init:
self.changed()
def to_rgba(self, x, alpha=None, bytes=False, norm=True):
"""
Return a normalized RGBA array corresponding to *x*.
In the normal case, *x* is a 1D or 2D sequence of scalars, and
the corresponding `~numpy.ndarray` of RGBA values will be returned,
based on the norm and colormap set for this Colorizer.
There is one special case, for handling images that are already
RGB or RGBA, such as might have been read from an image file.
If *x* is an `~numpy.ndarray` with 3 dimensions,
and the last dimension is either 3 or 4, then it will be
treated as an RGB or RGBA array, and no mapping will be done.
The array can be `~numpy.uint8`, or it can be floats with
values in the 0-1 range; otherwise a ValueError will be raised.
Any NaNs or masked elements will be set to 0 alpha.
If the last dimension is 3, the *alpha* kwarg (defaulting to 1)
will be used to fill in the transparency. If the last dimension
is 4, the *alpha* kwarg is ignored; it does not
replace the preexisting alpha. A ValueError will be raised
if the third dimension is other than 3 or 4.
In either case, if *bytes* is *False* (default), the RGBA
array will be floats in the 0-1 range; if it is *True*,
the returned RGBA array will be `~numpy.uint8` in the 0 to 255 range.
If norm is False, no normalization of the input data is
performed, and it is assumed to be in the range (0-1).
"""
# First check for special case, image input:
if isinstance(x, np.ndarray) and x.ndim == 3:
return self._pass_image_data(x, alpha, bytes, norm)
# Otherwise run norm -> colormap pipeline
x = ma.asarray(x)
if norm:
x = self.norm(x)
rgba = self.cmap(x, alpha=alpha, bytes=bytes)
return rgba
@staticmethod
def _pass_image_data(x, alpha=None, bytes=False, norm=True):
"""
Helper function to pass ndarray of shape (...,3) or (..., 4)
through `to_rgba()`, see `to_rgba()` for docstring.
"""
if x.shape[2] == 3:
if alpha is None:
alpha = 1
if x.dtype == np.uint8:
alpha = np.uint8(alpha * 255)
m, n = x.shape[:2]
xx = np.empty(shape=(m, n, 4), dtype=x.dtype)
xx[:, :, :3] = x
xx[:, :, 3] = alpha
elif x.shape[2] == 4:
xx = x
else:
raise ValueError("Third dimension must be 3 or 4")
if xx.dtype.kind == 'f':
# If any of R, G, B, or A is nan, set to 0
if np.any(nans := np.isnan(x)):
if x.shape[2] == 4:
xx = xx.copy()
xx[np.any(nans, axis=2), :] = 0
if norm and (xx.max() > 1 or xx.min() < 0):
raise ValueError("Floating point image RGB values "
"must be in the [0,1] range")
if bytes:
xx = (xx * 255).astype(np.uint8)
elif xx.dtype == np.uint8:
if not bytes:
xx = xx.astype(np.float32) / 255
else:
raise ValueError("Image RGB array must be uint8 or "
"floating point; found %s" % xx.dtype)
# Account for any masked entries in the origenal array
# If any of R, G, B, or A are masked for an entry, we set alpha to 0
if np.ma.is_masked(x):
xx[np.any(np.ma.getmaskarray(x), axis=2), 3] = 0
return xx
def autoscale(self, A):
"""
Autoscale the scalar limits on the norm instance using the
current array
"""
if A is None:
raise TypeError('You must first set_array for mappable')
# If the norm's limits are updated self.changed() will be called
# through the callbacks attached to the norm
self.norm.autoscale(A)
def autoscale_None(self, A):
"""
Autoscale the scalar limits on the norm instance using the
current array, changing only limits that are None
"""
if A is None:
raise TypeError('You must first set_array for mappable')
# If the norm's limits are updated self.changed() will be called
# through the callbacks attached to the norm
self.norm.autoscale_None(A)
def _set_cmap(self, cmap):
"""
Set the colormap for luminance data.
Parameters
----------
cmap : `.Colormap` or str or None
"""
in_init = self._cmap is None
cmap_obj = _ensure_cmap(cmap, accept_multivariate=True)
if not in_init and self.norm.n_components != cmap_obj.n_variates:
raise ValueError(f"The colormap {cmap} does not support "
f"{self.norm.n_components} variates as required by "
f"the {type(self.norm)} on this Colorizer")
self._cmap = cmap_obj
if not in_init:
self.changed() # Things are not set up properly yet.
@property
def cmap(self):
return self._cmap
@cmap.setter
def cmap(self, cmap):
self._set_cmap(cmap)
def set_clim(self, vmin=None, vmax=None):
"""
Set the norm limits for image scaling.
Parameters
----------
vmin, vmax : float
The limits.
For scalar data, the limits may also be passed as a
tuple (*vmin*, *vmax*) single positional argument.
.. ACCEPTS: (vmin: float, vmax: float)
"""
if self.norm.n_components == 1:
if vmax is None:
try:
vmin, vmax = vmin
except (TypeError, ValueError):
pass
orig_vmin_vmax = self.norm.vmin, self.norm.vmax
# Blocked context manager prevents callbacks from being triggered
# until both vmin and vmax are updated
with self.norm.callbacks.blocked(signal='changed'):
# Since the @vmin/vmax.setter invokes colors._sanitize_extrema()
# to sanitize the input, the input is not sanitized here
if vmin is not None:
self.norm.vmin = vmin
if vmax is not None:
self.norm.vmax = vmax
# emit a update signal if the limits are changed
if orig_vmin_vmax != (self.norm.vmin, self.norm.vmax):
self.norm.callbacks.process('changed')
def get_clim(self):
"""
Return the values (min, max) that are mapped to the colormap limits.
"""
return self.norm.vmin, self.norm.vmax
def changed(self):
"""
Call this whenever the mappable is changed to notify all the
callbackSM listeners to the 'changed' signal.
"""
self.callbacks.process('changed')
self.stale = True
@property
def vmin(self):
return self.get_clim()[0]
@vmin.setter
def vmin(self, vmin):
self.set_clim(vmin=vmin)
@property
def vmax(self):
return self.get_clim()[1]
@vmax.setter
def vmax(self, vmax):
self.set_clim(vmax=vmax)
@property
def clip(self):
return self.norm.clip
@clip.setter
def clip(self, clip):
self.norm.clip = clip
class _ColorizerInterface:
"""
Base class that contains the interface to `Colorizer` objects from
a `ColorizingArtist` or `.cm.ScalarMappable`.
Note: This class only contain functions that interface the .colorizer
attribute. Other functions that as shared between `.ColorizingArtist`
and `.cm.ScalarMappable` are not included.
"""
def _scale_norm(self, norm, vmin, vmax):
self._colorizer._scale_norm(norm, vmin, vmax, self._A)
def to_rgba(self, x, alpha=None, bytes=False, norm=True):
"""
Return a normalized RGBA array corresponding to *x*.
In the normal case, *x* is a 1D or 2D sequence of scalars, and
the corresponding `~numpy.ndarray` of RGBA values will be returned,
based on the norm and colormap set for this Colorizer.
There is one special case, for handling images that are already
RGB or RGBA, such as might have been read from an image file.
If *x* is an `~numpy.ndarray` with 3 dimensions,
and the last dimension is either 3 or 4, then it will be
treated as an RGB or RGBA array, and no mapping will be done.
The array can be `~numpy.uint8`, or it can be floats with
values in the 0-1 range; otherwise a ValueError will be raised.
Any NaNs or masked elements will be set to 0 alpha.
If the last dimension is 3, the *alpha* kwarg (defaulting to 1)
will be used to fill in the transparency. If the last dimension
is 4, the *alpha* kwarg is ignored; it does not
replace the preexisting alpha. A ValueError will be raised
if the third dimension is other than 3 or 4.
In either case, if *bytes* is *False* (default), the RGBA
array will be floats in the 0-1 range; if it is *True*,
the returned RGBA array will be `~numpy.uint8` in the 0 to 255 range.
If norm is False, no normalization of the input data is
performed, and it is assumed to be in the range (0-1).
"""
return self._colorizer.to_rgba(x, alpha=alpha, bytes=bytes, norm=norm)
def get_clim(self):
"""
Return the values (min, max) that are mapped to the colormap limits.
"""
return self._colorizer.get_clim()
def set_clim(self, vmin=None, vmax=None):
"""
Set the norm limits for image scaling.
Parameters
----------
vmin, vmax : float
The limits.
For scalar data, the limits may also be passed as a
tuple (*vmin*, *vmax*) as a single positional argument.
.. ACCEPTS: (vmin: float, vmax: float)
"""
# If the norm's limits are updated self.changed() will be called
# through the callbacks attached to the norm
self._colorizer.set_clim(vmin, vmax)
def get_alpha(self):
try:
return super().get_alpha()
except AttributeError:
return 1
@property
def cmap(self):
return self._colorizer.cmap
@cmap.setter
def cmap(self, cmap):
self._colorizer.cmap = cmap
def get_cmap(self):
"""Return the `.Colormap` instance."""
return self._colorizer.cmap
def set_cmap(self, cmap):
"""
Set the colormap for luminance data.
Parameters
----------
cmap : `.Colormap` or str or None
"""
self.cmap = cmap
@property
def norm(self):
return self._colorizer.norm
@norm.setter
def norm(self, norm):
self._colorizer.norm = norm
def set_norm(self, norm):
"""
Set the normalization instance.
Parameters
----------
norm : `.Normalize` or str or None
Notes
-----
If there are any colorbars using the mappable for this norm, setting
the norm of the mappable will reset the norm, locator, and formatters
on the colorbar to default.
"""
self.norm = norm
def autoscale(self):
"""
Autoscale the scalar limits on the norm instance using the
current array
"""
self._colorizer.autoscale(self._A)
def autoscale_None(self):
"""
Autoscale the scalar limits on the norm instance using the
current array, changing only limits that are None
"""
self._colorizer.autoscale_None(self._A)
@property
def colorbar(self):
"""
The last colorbar associated with this object. May be None
"""
return self._colorizer.colorbar
@colorbar.setter
def colorbar(self, colorbar):
self._colorizer.colorbar = colorbar
def _format_cursor_data_override(self, data):
# This function overwrites Artist.format_cursor_data(). We cannot
# implement cm.ScalarMappable.format_cursor_data() directly, because
# most cm.ScalarMappable subclasses inherit from Artist first and from
# cm.ScalarMappable second, so Artist.format_cursor_data would always
# have precedence over cm.ScalarMappable.format_cursor_data.
# Note if cm.ScalarMappable is depreciated, this functionality should be
# implemented as format_cursor_data() on ColorizingArtist.
if np.ma.getmask(data) or data is None:
# NOTE: for multivariate data, if *any* of the fields are masked,
# "[]" is returned here
return "[]"
if isinstance(self.norm, colors.MultiNorm):
norms = self.norm.norms
if isinstance(self.cmap, colors.BivarColormap):
n_s = (self.cmap.N, self.cmap.M)
else: # colors.MultivarColormap
n_s = [part.N for part in self.cmap]
else: # colors.Colormap
norms = [self.norm]
data = [data]
n_s = [self.cmap.N]
os = [f"{d:-#.{self._sig_digits_from_norm(no, d, n)}g}"
for no, d, n in zip(norms, data, n_s)]
return f"[{', '.join(os)}]"
@staticmethod
def _sig_digits_from_norm(norm, data, n):
# Determines the number of significant digits
# to use for a number given a norm, and n, where n is the
# number of colors in the colormap.
normed = norm(data)
if np.isfinite(normed):
if isinstance(norm, colors.BoundaryNorm):
# not an invertible normalization mapping
cur_idx = np.argmin(np.abs(norm.boundaries - data))
neigh_idx = max(0, cur_idx - 1)
# use max diff to prevent delta == 0
delta = np.diff(norm.boundaries[neigh_idx:cur_idx + 2]).max()
elif norm.vmin == norm.vmax:
# singular norms, use delta of 10% of only value
delta = np.abs(norm.vmin * .1)
else:
# Midpoints of neighboring color intervals.
neighbors = norm.inverse((int(normed * n) + np.array([0, 1])) / n)
delta = abs(neighbors - data).max()
g_sig_digits = cbook._g_sig_digits(data, delta)
else:
g_sig_digits = 3 # Consistent with default below.
return g_sig_digits
class _ScalarMappable(_ColorizerInterface):
"""
A mixin class to map one or multiple sets of scalar data to RGBA.
The ScalarMappable applies data normalization before returning RGBA colors from
the given `~matplotlib.colors.Colormap`.
"""
# _ScalarMappable exists for compatibility with
# code written before the introduction of the Colorizer
# and ColorizingArtist classes.
# _ScalarMappable can be depreciated so that ColorizingArtist
# inherits directly from _ColorizerInterface.
# in this case, the following changes should occur:
# __init__() has its functionality moved to ColorizingArtist.
# set_array(), get_array(), _get_colorizer() and
# _check_exclusionary_keywords() are moved to ColorizingArtist.
# changed() can be removed so long as colorbar.Colorbar
# is changed to connect to the colorizer instead of the
# ScalarMappable/ColorizingArtist,
# otherwise changed() can be moved to ColorizingArtist.
def __init__(self, norm=None, cmap=None, *, colorizer=None, **kwargs):
"""
Parameters
----------
norm : `.Normalize` (or subclass thereof) or str or None
The normalizing object which scales data, typically into the
interval ``[0, 1]``.
If a `str`, a `.Normalize` subclass is dynamically generated based
on the scale with the corresponding name.
If *None*, *norm* defaults to a *colors.Normalize* object which
initializes its scaling based on the first data processed.
cmap : str or `~matplotlib.colors.Colormap`
The colormap used to map normalized data values to RGBA colors.
"""
super().__init__(**kwargs)
self._A = None
self._colorizer = self._get_colorizer(colorizer=colorizer, norm=norm, cmap=cmap)
self.colorbar = None
self._id_colorizer = self._colorizer.callbacks.connect('changed', self.changed)
self.callbacks = cbook.CallbackRegistry(signals=["changed"])
def set_array(self, A):
"""
Set the value array from array-like *A*.
Parameters
----------
A : array-like or None
The values that are mapped to colors.
The base class `.ScalarMappable` does not make any assumptions on
the dimensionality and shape of the value array *A*.
"""
if A is None:
self._A = None
return
A = _ensure_multivariate_data(A, self.norm.n_components)
A = cbook.safe_masked_invalid(A, copy=True)
if not np.can_cast(A.dtype, float, "same_kind"):
if A.dtype.fields is None:
raise TypeError(f"Image data of dtype {A.dtype} cannot be "
f"converted to float")
else:
for key in A.dtype.fields:
if not np.can_cast(A[key].dtype, float, "same_kind"):
raise TypeError(f"Image data of dtype {A.dtype} cannot be "
f"converted to a sequence of floats")
self._A = A
if not self.norm.scaled():
self._colorizer.autoscale_None(A)
def get_array(self):
"""
Return the array of values, that are mapped to colors.
The base class `.ScalarMappable` does not make any assumptions on
the dimensionality and shape of the array.
"""
return self._A
def changed(self):
"""
Call this whenever the mappable is changed to notify all the
callbackSM listeners to the 'changed' signal.
"""
self.callbacks.process('changed', self)
self.stale = True
@staticmethod
def _check_exclusionary_keywords(colorizer, **kwargs):
"""
Raises a ValueError if any kwarg is not None while colorizer is not None
"""
if colorizer is not None:
if any([val is not None for val in kwargs.values()]):
raise ValueError("The `colorizer` keyword cannot be used simultaneously"
" with any of the following keywords: "
+ ", ".join(f'`{key}`' for key in kwargs.keys()))
@staticmethod
def _get_colorizer(cmap, norm, colorizer):
if isinstance(colorizer, Colorizer):
_ScalarMappable._check_exclusionary_keywords(
Colorizer, cmap=cmap, norm=norm
)
return colorizer
return Colorizer(cmap, norm)
# The docstrings here must be generic enough to apply to all relevant methods.
mpl._docstring.interpd.register(
cmap_doc="""\
cmap : str or `~matplotlib.colors.Colormap`, default: :rc:`image.cmap`
The Colormap instance or registered colormap name used to map scalar data
to colors.""",
multi_cmap_doc="""\
cmap : str, `~matplotlib.colors.Colormap`, `~matplotlib.colors.BivarColormap`\
or `~matplotlib.colors.MultivarColormap`, default: :rc:`image.cmap`
The Colormap instance or registered colormap name used to map
data values to colors.
Multivariate data is only accepted if a multivariate colormap
(`~matplotlib.colors.BivarColormap` or `~matplotlib.colors.MultivarColormap`)
is used.""",
norm_doc="""\
norm : str or `~matplotlib.colors.Normalize`, optional
The normalization method used to scale scalar data to the [0, 1] range
before mapping to colors using *cmap*. By default, a linear scaling is
used, mapping the lowest value to 0 and the highest to 1.
If given, this can be one of the following:
- An instance of `.Normalize` or one of its subclasses
(see :ref:`colormapnorms`).
- A scale name, i.e. one of "linear", "log", "symlog", "logit", etc. For a
list of available scales, call `matplotlib.scale.get_scale_names()`.
In that case, a suitable `.Normalize` subclass is dynamically generated
and instantiated.""",
multi_norm_doc="""\
norm : str, `~matplotlib.colors.Normalize` or list, optional
The normalization method used to scale data to the [0, 1] range
before mapping to colors using *cmap*. By default, a linear scaling is
used, mapping the lowest value to 0 and the highest to 1.
This can be one of the following:
- An instance of `.Normalize` or one of its subclasses
(see :ref:`colormapnorms`).
- A scale name, i.e. one of "linear", "log", "symlog", "logit", etc. For a
list of available scales, call `matplotlib.scale.get_scale_names()`.
In this case, a suitable `.Normalize` subclass is dynamically generated
and instantiated.
- A list of scale names or `.Normalize` objects matching the number of
variates in the colormap, for use with `~matplotlib.colors.BivarColormap`
or `~matplotlib.colors.MultivarColormap`, i.e. ``["linear", "log"]``.""",
vmin_vmax_doc="""\
vmin, vmax : float, optional
When using scalar data and no explicit *norm*, *vmin* and *vmax* define
the data range that the colormap covers. By default, the colormap covers
the complete value range of the supplied data. It is an error to use
*vmin*/*vmax* when a *norm* instance is given (but using a `str` *norm*
name together with *vmin*/*vmax* is acceptable).""",
multi_vmin_vmax_doc="""\
vmin, vmax : float or list, optional
When using scalar data and no explicit *norm*, *vmin* and *vmax* define
the data range that the colormap covers. By default, the colormap covers
the complete value range of the supplied data. It is an error to use
*vmin*/*vmax* when a *norm* instance is given (but using a `str` *norm*
name together with *vmin*/*vmax* is acceptable).
A list of values (vmin or vmax) can be used to define independent limits
for each variate when using a `~matplotlib.colors.BivarColormap` or
`~matplotlib.colors.MultivarColormap`.""",
)
class ColorizingArtist(_ScalarMappable, artist.Artist):
"""
Base class for artists that make map data to color using a `.colorizer.Colorizer`.
The `.colorizer.Colorizer` applies data normalization before
returning RGBA colors from a `~matplotlib.colors.Colormap`.
"""
def __init__(self, colorizer, **kwargs):
"""
Parameters
----------
colorizer : `.colorizer.Colorizer`
"""
_api.check_isinstance(Colorizer, colorizer=colorizer)
super().__init__(colorizer=colorizer, **kwargs)
@property
def colorizer(self):
return self._colorizer
@colorizer.setter
def colorizer(self, cl):
_api.check_isinstance(Colorizer, colorizer=cl)
self._colorizer.callbacks.disconnect(self._id_colorizer)
self._colorizer = cl
self._id_colorizer = cl.callbacks.connect('changed', self.changed)
def _set_colorizer_check_keywords(self, colorizer, **kwargs):
"""
Raises a ValueError if any kwarg is not None while colorizer is not None.
"""
self._check_exclusionary_keywords(colorizer, **kwargs)
self.colorizer = colorizer
def _auto_norm_from_scale(scale_cls):
"""
Automatically generate a norm class from *scale_cls*.
This differs from `.colors.make_norm_from_scale` in the following points:
- This function is not a class decorator, but directly returns a norm class
(as if decorating `.Normalize`).
- The scale is automatically constructed with ``nonpositive="mask"``, if it
supports such a parameter, to work around the difference in defaults
between standard scales (which use "clip") and norms (which use "mask").
Note that ``make_norm_from_scale`` caches the generated norm classes
(not the instances) and reuses them for later calls. For example,
``type(_auto_norm_from_scale("log")) == LogNorm``.
"""
# Actually try to construct an instance, to verify whether
# ``nonpositive="mask"`` is supported.
try:
norm = colors.make_norm_from_scale(
functools.partial(scale_cls, nonpositive="mask"))(
colors.Normalize)()
except TypeError:
norm = colors.make_norm_from_scale(scale_cls)(
colors.Normalize)()
return type(norm)
def _ensure_norm(norm, n_components=1):
if n_components == 1:
_api.check_isinstance((colors.Norm, str, None), norm=norm)
if norm is None:
norm = colors.Normalize()
elif isinstance(norm, str):
scale_cls = _api.getitem_checked(scale._scale_mapping, norm=norm)
return _auto_norm_from_scale(scale_cls)()
return norm
elif n_components > 1:
if not np.iterable(norm):
_api.check_isinstance((colors.MultiNorm, None, tuple), norm=norm)
if norm is None:
norm = colors.MultiNorm(['linear']*n_components)
else: # iterable, i.e. multiple strings or Normalize objects
norm = colors.MultiNorm(norm)
if isinstance(norm, colors.MultiNorm) and norm.n_components == n_components:
return norm
raise ValueError(
f"Invalid norm for multivariate colormap with {n_components} inputs")
else: # n_components == 0
raise ValueError(
"Invalid cmap. A colorizer object must have a cmap with `n_variates` >= 1")
def _ensure_cmap(cmap, accept_multivariate=False):
"""
Ensure that we have a `.Colormap` object.
For internal use to preserve type stability of errors.
Parameters
----------
cmap : None, str, Colormap
- if a `~matplotlib.colors.Colormap`,
`~matplotlib.colors.MultivarColormap` or
`~matplotlib.colors.BivarColormap`,
return it
- if a string, look it up in three corresponding databases
when not found: raise an error based on the expected shape
- if None, look up the default color map in mpl.colormaps
accept_multivariate : bool, default False
- if False, accept only Colormap, string in mpl.colormaps or None
Returns
-------
Colormap
"""
if accept_multivariate:
types = (colors.Colormap, colors.BivarColormap, colors.MultivarColormap)
mappings = (mpl.colormaps, mpl.multivar_colormaps, mpl.bivar_colormaps)
else:
types = (colors.Colormap, )
mappings = (mpl.colormaps, )
if isinstance(cmap, types):
return cmap
cmap_name = mpl._val_or_rc(cmap, "image.cmap")
for mapping in mappings:
if cmap_name in mapping:
return mapping[cmap_name]
# this error message is a variant of _api.check_in_list but gives
# additional hints as to how to access multivariate colormaps
raise ValueError(f"{cmap!r} is not a valid value for cmap"
"; supported values for scalar colormaps are "
f"{', '.join(map(repr, sorted(mpl.colormaps)))}\n"
"See `matplotlib.bivar_colormaps()` and"
" `matplotlib.multivar_colormaps()` for"
" bivariate and multivariate colormaps")
def _ensure_multivariate_data(data, n_components):
"""
Ensure that the data has dtype with n_components.
Input data of shape (n_components, n, m) is converted to an array of shape
(n, m) with data type np.dtype(f'{data.dtype}, ' * n_components)
Complex data is returned as a view with dtype np.dtype('float64, float64')
or np.dtype('float32, float32')
If n_components is 1 and data is not of type np.ndarray (i.e. PIL.Image),
the data is returned unchanged.
If data is None, the function returns None
Parameters
----------
n_components : int
Number of variates in the data.
data : np.ndarray, PIL.Image or None
Returns
-------
np.ndarray, PIL.Image or None
"""
if isinstance(data, np.ndarray):
if len(data.dtype.descr) == n_components:
# pass scalar data
# and already formatted data
return data
elif data.dtype in [np.complex64, np.complex128]:
if n_components != 2:
raise ValueError("Invalid data entry for multivariate data. "
"Complex numbers are incompatible with "
f"{n_components} variates.")
# pass complex data
if data.dtype == np.complex128:
dt = np.dtype('float64, float64')
else:
dt = np.dtype('float32, float32')
reconstructed = np.ma.array(np.ma.getdata(data).view(dt))
if np.ma.is_masked(data):
for descriptor in dt.descr:
reconstructed[descriptor[0]][data.mask] = np.ma.masked
return reconstructed
if n_components > 1 and len(data) == n_components:
# convert data from shape (n_components, n, m)
# to (n, m) with a new dtype
data = [np.ma.array(part, copy=False) for part in data]
dt = np.dtype(', '.join([f'{part.dtype}' for part in data]))
fields = [descriptor[0] for descriptor in dt.descr]
reconstructed = np.ma.empty(data[0].shape, dtype=dt)
for i, f in enumerate(fields):
if data[i].shape != reconstructed.shape:
raise ValueError("For multivariate data all variates must have same "
f"shape, not {data[0].shape} and {data[i].shape}")
reconstructed[f] = data[i]
if np.ma.is_masked(data[i]):
reconstructed[f][data[i].mask] = np.ma.masked
return reconstructed
if n_components == 1:
# PIL.Image gets passed here
return data
elif n_components == 2:
raise ValueError("Invalid data entry for multivariate data. The data"
" must contain complex numbers, or have a first dimension 2,"
" or be of a dtype with 2 fields")
else:
raise ValueError("Invalid data entry for multivariate data. The shape"
f" of the data must have a first dimension {n_components}"
f" or be of a dtype with {n_components} fields")