#!/usr/bin/env python3
"""
Various tools that may be useful while making plots.
"""
# WARNING: Cannot import 'rc' anywhere in this file or we get circular import
# issues. The rc param validators need functions in this file.
import functools
import re
from numbers import Integral, Real
import matplotlib.colors as mcolors
import matplotlib.font_manager as mfonts
import numpy as np
from matplotlib import rcParams as rc_matplotlib
from .externals import hsluv
from .internals import ic # noqa: F401
from .internals import _not_none, docstring, warnings
__all__ = [
'arange',
'edges',
'edges2d',
'get_colors',
'set_hue',
'set_saturation',
'set_luminance',
'set_alpha',
'shift_hue',
'scale_saturation',
'scale_luminance',
'to_hex',
'to_rgb',
'to_xyz',
'to_rgba',
'to_xyza',
'units',
'shade', # deprecated
'saturate', # deprecated
]
UNIT_REGEX = re.compile(
r'\A([-+]?[0-9._]+(?:[eE][-+]?[0-9_]+)?)(.*)\Z' # float with trailing units
)
UNIT_DICT = {
'in': 1.0,
'ft': 12.0,
'yd': 36.0,
'm': 39.37,
'dm': 3.937,
'cm': 0.3937,
'mm': 0.03937,
'pc': 1 / 6.0,
'pt': 1 / 72.0,
'ly': 3.725e17,
}
# Color docstrings
_docstring_rgba = """
color : color-spec
The color. Sanitized with `to_rgba`.
"""
_docstring_to_rgb = """
color : color-spec
The color. Can be a 3-tuple or 4-tuple of channel values, a hex
string, a registered color name, a cycle color like ``'C0'``, or
a 2-tuple colormap coordinate specification like ``('magma', 0.5)``
(see `~proplot.colors.ColorDatabase` for details).
If `space` is ``'rgb'``, this is a tuple of RGB values, and any
channels are larger than ``2``, the channels are assumed to be
on the ``0`` to ``255`` scale and are divided by ``255``.
space : {'rgb', 'hsv', 'hcl', 'hpl', 'hsl'}, optional
The colorspace for the input channel values. Ignored unless `color`
is a tuple of numbers.
cycle : str, default: :rcraw:`cycle`
The registered color cycle name used to interpret colors that
look like ``'C0'``, ``'C1'``, etc.
clip : bool, default: True
Whether to clip channel values into the valid ``0`` to ``1`` range.
Setting this to ``False`` can result in invalid colors.
"""
_docstring_space = """
space : {'hcl', 'hpl', 'hsl', 'hsv'}, optional
The hue-saturation-luminance-like colorspace used to transform the color.
Default is the strictly perceptually uniform colorspace ``'hcl'``.
"""
_docstring_hex = """
color : str
An 8-digit HEX string indicating the
red, green, blue, and alpha channel values.
"""
docstring._snippet_manager['utils.color'] = _docstring_rgba
docstring._snippet_manager['utils.hex'] = _docstring_hex
docstring._snippet_manager['utils.space'] = _docstring_space
docstring._snippet_manager['utils.to'] = _docstring_to_rgb
def _keep_units(func):
"""
Very simple decorator to strip and re-apply the same units.
"""
# NOTE: Native UnitRegistry.wraps() is not sufficient since it enforces
# unit types rather than arbitrary units. This wrapper is similar.
@functools.wraps(func)
def _with_stripped_units(data, *args, **kwargs):
units = 1
if hasattr(data, 'units') and hasattr(data, 'magnitude'):
data, units = data.magnitude, data.units
result = func(data, *args, **kwargs)
return result * units
return _with_stripped_units
[docs]def arange(min_, *args):
"""
Identical to `numpy.arange` but with inclusive endpoints. For example,
``pplt.arange(2, 4)`` returns the numpy array ``[2, 3, 4]`` instead of
``[2, 3]``. This is useful for generating lists of tick locations or
colormap levels, e.g. ``ax.format(xlocator=pplt.arange(0, 10))``
or ``ax.pcolor(levels=pplt.arange(0, 10))``.
Parameters
----------
*args : float
If three arguments are passed, these are the minimum, maximum, and step
size. If fewer than three arguments are passed, the step size is ``1``.
If one argument is passed, this is the maximum, and the minimum is ``0``.
Returns
-------
numpy.ndarray
Array of points.
See also
--------
numpy.arange
proplot.constructor.Locator
proplot.axes.CartesianAxes.format
proplot.axes.PolarAxes.format
proplot.axes.GeoAxes.format
proplot.axes.Axes.colorbar
proplot.axes.PlotAxes
"""
# Optional arguments just like np.arange
if len(args) == 0:
max_ = min_
min_ = 0
step = 1
elif len(args) == 1:
max_ = args[0]
step = 1
elif len(args) == 2:
max_ = args[0]
step = args[1]
else:
raise ValueError('Function takes from one to three arguments.')
# All input is integer
if all(isinstance(val, Integral) for val in (min_, max_, step)):
min_, max_, step = np.int64(min_), np.int64(max_), np.int64(step)
max_ += np.sign(step)
# Input is float or mixed, cast to float64
# Don't use np.nextafter with np.finfo(np.dtype(np.float64)).max, because
# round-off errors from continually adding step to min mess this up
else:
min_, max_, step = np.float64(min_), np.float64(max_), np.float64(step)
max_ += 0.5 * step
return np.arange(min_, max_, step)
[docs]@_keep_units
def edges(z, axis=-1):
"""
Calculate the approximate "edge" values along an axis given "center" values.
The size of the axis is increased by one. This is used internally to calculate
coordinate edges when you supply coordinate centers to pseudocolor commands.
Parameters
----------
z : array-like
An array of any shape.
axis : int, optional
The axis along which "edges" are calculated. The size of this
axis will be increased by one.
Returns
-------
numpy.ndarray
Array of "edge" coordinates.
See also
--------
edges2d
proplot.axes.PlotAxes.pcolor
proplot.axes.PlotAxes.pcolormesh
proplot.axes.PlotAxes.pcolorfast
"""
z = np.asarray(z)
z = np.swapaxes(z, axis, -1)
*dims, n = z.shape
zb = np.zeros((*dims, n + 1))
# Inner edges
zb[..., 1:-1] = 0.5 * (z[..., :-1] + z[..., 1:])
# Outer edges
zb[..., 0] = 1.5 * z[..., 0] - 0.5 * z[..., 1]
zb[..., -1] = 1.5 * z[..., -1] - 0.5 * z[..., -2]
return np.swapaxes(zb, axis, -1)
[docs]@_keep_units
def edges2d(z):
"""
Calculate the approximate "edge" values given a 2D grid of "center" values.
The size of both axes is increased by one. This is used internally to calculate
coordinate edges when you supply coordinate to pseudocolor commands.
Parameters
----------
z : array-like
A 2D array.
Returns
-------
numpy.ndarray
Array of "edge" coordinates.
See also
--------
edges
proplot.axes.PlotAxes.pcolor
proplot.axes.PlotAxes.pcolormesh
proplot.axes.PlotAxes.pcolorfast
"""
z = np.asarray(z)
if z.ndim != 2:
raise ValueError(f'Input must be a 2D array, but got {z.ndim}D.')
ny, nx = z.shape
zb = np.zeros((ny + 1, nx + 1))
# Inner edges
zb[1:-1, 1:-1] = 0.25 * (z[1:, 1:] + z[:-1, 1:] + z[1:, :-1] + z[:-1, :-1])
# Outer edges
zb[0, :] += edges(1.5 * z[0, :] - 0.5 * z[1, :])
zb[-1, :] += edges(1.5 * z[-1, :] - 0.5 * z[-2, :])
zb[:, 0] += edges(1.5 * z[:, 0] - 0.5 * z[:, 1])
zb[:, -1] += edges(1.5 * z[:, -1] - 0.5 * z[:, -2])
zb[[0, 0, -1, -1], [0, -1, -1, 0]] *= 0.5 # corner correction
return zb
[docs]def get_colors(*args, **kwargs):
"""
Get the colors associated with a registered or
on-the-fly color cycle or colormap.
Parameters
----------
*args, **kwargs
Passed to `~proplot.constructor.Cycle`.
Returns
-------
colors : list of str
A list of HEX strings.
See also
--------
proplot.constructor.Cycle
proplot.constructor.Colormap
"""
from .constructor import Cycle # delayed to avoid cyclic imports
cycle = Cycle(*args, **kwargs)
colors = [to_hex(dict_['color']) for dict_ in cycle]
return colors
def _transform_color(func, color, space):
"""
Standardize input for color transformation functions.
"""
*color, opacity = to_rgba(color)
color = to_xyz(color, space=space)
color = func(list(color)) # apply transform
return to_hex((*color, opacity), space=space)
[docs]@docstring._snippet_manager
def shift_hue(color, shift=0, space='hcl'):
"""
Shift the hue channel of a color.
Parameters
----------
%(utils.color)s
shift : float, optional
The HCL hue channel is offset by this value.
%(utils.space)s
Returns
-------
%(utils.hex)s
See also
--------
set_hue
set_saturation
set_luminance
set_alpha
scale_saturation
scale_luminance
"""
def func(channels):
channels[0] += shift
channels[0] %= 360
return channels
return _transform_color(func, color, space)
[docs]@docstring._snippet_manager
def scale_saturation(color, scale=1, space='hcl'):
"""
Scale the saturation channel of a color.
Parameters
----------
%(utils.color)s
scale : float, optional
The HCL saturation channel is multiplied by this value.
%(utils.space)s
Returns
-------
%(utils.hex)s
See also
--------
set_hue
set_saturation
set_luminance
set_alpha
shift_hue
scale_luminance
"""
def func(channels):
channels[1] *= scale
return channels
return _transform_color(func, color, space)
[docs]@docstring._snippet_manager
def scale_luminance(color, scale=1, space='hcl'):
"""
Scale the luminance channel of a color.
Parameters
----------
%(utils.color)s
scale : float, optional
The luminance channel is multiplied by this value.
%(utils.space)s
Returns
-------
%(utils.hex)s
See also
--------
set_hue
set_saturation
set_luminance
set_alpha
shift_hue
scale_saturation
"""
def func(channels):
channels[2] *= scale
return channels
return _transform_color(func, color, space)
[docs]@docstring._snippet_manager
def set_hue(color, hue, space='hcl'):
"""
Return a color with a different hue and the same luminance and saturation
as the input color.
Parameters
----------
%(utils.color)s
hue : float, optional
The new hue. Should lie between ``0`` and ``360`` degrees.
%(utils.space)s
Returns
-------
%(utils.hex)s
See also
--------
set_saturation
set_luminance
set_alpha
shift_hue
scale_saturation
scale_luminance
"""
def func(channels):
channels[0] = hue
return channels
return _transform_color(func, color, space)
[docs]@docstring._snippet_manager
def set_saturation(color, saturation, space='hcl'):
"""
Return a color with a different saturation and the same hue and luminance
as the input color.
Parameters
----------
%(utils.color)s
saturation : float, optional
The new saturation. Should lie between ``0`` and ``360`` degrees.
%(utils.space)s
Returns
-------
%(utils.hex)s
See also
--------
set_hue
set_luminance
set_alpha
shift_hue
scale_saturation
scale_luminance
"""
def func(channels):
channels[1] = saturation
return channels
return _transform_color(func, color, space)
[docs]@docstring._snippet_manager
def set_luminance(color, luminance, space='hcl'):
"""
Return a color with a different luminance and the same hue and saturation
as the input color.
Parameters
----------
%(utils.color)s
luminance : float, optional
The new luminance. Should lie between ``0`` and ``100``.
%(utils.space)s
Returns
-------
%(utils.hex)s
See also
--------
set_hue
set_saturation
set_alpha
shift_hue
scale_saturation
scale_luminance
"""
def func(channels):
channels[2] = luminance
return channels
return _transform_color(func, color, space)
[docs]@docstring._snippet_manager
def set_alpha(color, alpha):
"""
Return a color with the opacity channel set to the specified value.
Parameters
----------
%(utils.color)s
alpha : float, optional
The new opacity. Should be between ``0`` and ``1``.
Returns
-------
%(utils.hex)s
See also
--------
set_hue
set_saturation
set_luminance
shift_hue
scale_saturation
scale_luminance
"""
color = list(to_rgba(color))
color[3] = alpha
return to_hex(color)
def _translate_cycle_color(color, cycle=None):
"""
Parse the input cycle color.
"""
if isinstance(cycle, str):
from .colors import _cmap_database
try:
cycle = _cmap_database[cycle].colors
except (KeyError, AttributeError):
cycles = sorted(
name
for name, cmap in _cmap_database.items()
if isinstance(cmap, mcolors.ListedColormap)
)
raise ValueError(
f'Invalid color cycle {cycle!r}. Options are: '
+ ', '.join(map(repr, cycles))
+ '.'
)
elif cycle is None:
cycle = rc_matplotlib['axes.prop_cycle'].by_key()
if 'color' not in cycle:
cycle = ['k']
else:
cycle = cycle['color']
else:
raise ValueError(f'Invalid cycle {cycle!r}.')
return cycle[int(color[-1]) % len(cycle)]
[docs]@docstring._snippet_manager
def to_hex(color, space='rgb', cycle=None, keep_alpha=True):
"""
Translate the color from an arbitrary colorspace to a HEX string.
This is a generalization of `matplotlib.colors.to_hex`.
Parameters
----------
%(utils.to)s
keep_alpha : bool, default: True
Whether to keep the opacity channel. If ``True`` an 8-digit HEX
is returned. Otherwise a 6-digit HEX is returned.
Returns
-------
%(utils.hex)s
See also
--------
to_rgb
to_rgba
to_xyz
to_xyza
"""
rgba = to_rgba(color, space=space, cycle=cycle)
return mcolors.to_hex(rgba, keep_alpha=keep_alpha)
[docs]@docstring._snippet_manager
def to_rgb(color, space='rgb', cycle=None):
"""
Translate the color from an arbitrary colorspace to an RGB tuple. This is
a generalization of `matplotlib.colors.to_rgb` and the inverse of `to_xyz`.
Parameters
----------
%(utils.to)s
Returns
-------
color : 3-tuple
An RGB tuple.
See also
--------
to_hex
to_rgba
to_xyz
to_xyza
"""
return to_rgba(color, space=space, cycle=cycle)[:3]
[docs]@docstring._snippet_manager
def to_rgba(color, space='rgb', cycle=None, clip=True):
"""
Translate the color from an arbitrary colorspace to an RGBA tuple. This is
a generalization of `matplotlib.colors.to_rgba` and the inverse of `to_xyz`.
Parameters
----------
%(utils.to)s
Returns
-------
color : 4-tuple
An RGBA tuple.
See also
--------
to_hex
to_rgb
to_xyz
to_xyza
"""
# Translate color cycle strings
if isinstance(color, str) and re.match(r'\AC[0-9]\Z', color):
color = _translate_cycle_color(color, cycle=cycle)
# Translate RGB strings and (colormap, index) tuples
# NOTE: Cannot use is_color_like because might have HSL channel values
opacity = 1
if (
isinstance(color, str)
or np.iterable(color) and len(color) == 2
):
color = mcolors.to_rgba(color) # also enforced validity
if (
not np.iterable(color)
or len(color) not in (3, 4)
or not all(isinstance(c, Real) for c in color)
):
raise ValueError(f'Invalid color-spec {color!r}.')
if len(color) == 4:
*color, opacity = color
# Translate arbitrary colorspaces
if space == 'rgb':
if any(c > 2 for c in color):
color = tuple(c / 255 for c in color) # scale to within 0-1
else:
pass
elif space == 'hsv':
color = hsluv.hsl_to_rgb(*color)
elif space == 'hcl':
color = hsluv.hcl_to_rgb(*color)
elif space == 'hsl':
color = hsluv.hsluv_to_rgb(*color)
elif space == 'hpl':
color = hsluv.hpluv_to_rgb(*color)
else:
raise ValueError(f'Invalid colorspace {space!r}.')
# Clip values. This should only be disabled when testing
# translation functions.
if clip:
color = np.clip(color, 0, 1) # clip to valid range
# Return RGB or RGBA
return (*color, opacity)
[docs]@docstring._snippet_manager
def to_xyz(color, space='hcl'):
"""
Translate color in *any* format to a tuple of channel values in *any*
colorspace. This is the inverse of `to_rgb`.
Parameters
----------
%(utils.color)s
space : {'hcl', 'hpl', 'hsl', 'hsv', 'rgb'}, optional
The colorspace for the output channel values.
Returns
-------
color : 3-tuple
Tuple of channel values for the colorspace `space`.
See also
--------
to_hex
to_rgb
to_rgba
to_xyza
"""
return to_xyza(color, space)[:3]
[docs]@docstring._snippet_manager
def to_xyza(color, space='hcl'):
"""
Translate color in *any* format to a tuple of channel values in *any*
colorspace. This is the inverse of `to_rgba`.
Parameters
----------
%(utils.color)s
space : {'hcl', 'hpl', 'hsl', 'hsv', 'rgb'}, optional
The colorspace for the output channel values.
Returns
-------
color : 3-tuple
Tuple of channel values for the colorspace `space`.
See also
--------
to_hex
to_rgb
to_rgba
to_xyz
"""
# Run tuple conversions
# NOTE: Don't pass color tuple, because we may want to permit
# out-of-bounds RGB values to invert conversion
*color, opacity = to_rgba(color)
if space == 'rgb':
pass
elif space == 'hsv':
color = hsluv.rgb_to_hsl(*color) # rgb_to_hsv would also work
elif space == 'hcl':
color = hsluv.rgb_to_hcl(*color)
elif space == 'hsl':
color = hsluv.rgb_to_hsluv(*color)
elif space == 'hpl':
color = hsluv.rgb_to_hpluv(*color)
else:
raise ValueError(f'Invalid colorspace {space}.')
return (*color, opacity)
def _fontsize_to_pt(size):
"""
Translate font preset size or unit string to points.
"""
scalings = mfonts.font_scalings
if not isinstance(size, str):
return size
if size in mfonts.font_scalings:
return rc_matplotlib['font.size'] * scalings[size]
try:
return units(size, 'pt')
except ValueError:
raise KeyError(
f'Invalid font size {size!r}. Can be points or one of the preset scalings: '
+ ', '.join(f'{key!r} ({value})' for key, value in scalings.items())
+ '.'
)
[docs]@warnings._rename_kwargs('0.6.0', units='dest')
def units(
value, numeric=None, dest=None, *, fontsize=None, figure=None, axes=None, width=None
):
"""
Convert values between arbitrary physical units. This is used internally all
over proplot, permitting flexible units for various keyword arguments.
Parameters
----------
value : float or str or sequence
A size specifier or sequence of size specifiers. If numeric, units are
converted from `numeric` to `dest`. If string, units are converted to
`dest` according to the string specifier. The string should look like
``'123.456unit'``, where the number is the magnitude and ``'unit'``
matches a key in the below table.
.. _units_table:
========= =====================================================
Key Description
========= =====================================================
``'m'`` Meters
``'dm'`` Decimeters
``'cm'`` Centimeters
``'mm'`` Millimeters
``'yd'`` Yards
``'ft'`` Feet
``'in'`` Inches
``'pc'`` `Pica <pc_>`_ (1/6 inches)
``'pt'`` `Points <pt_>`_ (1/72 inches)
``'px'`` Pixels on screen, using dpi of :rcraw:`figure.dpi`
``'pp'`` Pixels once printed, using dpi of :rcraw:`savefig.dpi`
``'em'`` `Em square <em_>`_ for :rcraw:`font.size`
``'en'`` `En square <en_>`_ for :rcraw:`font.size`
``'Em'`` `Em square <em_>`_ for :rcraw:`axes.titlesize`
``'En'`` `En square <en_>`_ for :rcraw:`axes.titlesize`
``'ax'`` Axes-relative units (not always available)
``'fig'`` Figure-relative units (not always available)
``'ly'`` Light years ;)
========= =====================================================
.. _pt: https://en.wikipedia.org/wiki/Point_(typography)
.. _pc: https://en.wikipedia.org/wiki/Pica_(typography)
.. _em: https://en.wikipedia.org/wiki/Em_(typography)
.. _en: https://en.wikipedia.org/wiki/En_(typography)
numeric : str, default: 'in'
The units associated with numeric input.
dest : str, default: `numeric`
The destination units.
fontsize : str or float, default: :rc:`font.size` or :rc:`axes.titlesize`
The font size in points used for scaling. Default is
:rcraw:`font.size` for ``em`` and ``en`` units and
:rcraw:`axes.titlesize` for ``Em`` and ``En`` units.
axes : `~matplotlib.axes.Axes`, optional
The axes to use for scaling units that look like ``'0.1ax'``.
figure : `~matplotlib.figure.Figure`, optional
The figure to use for scaling units that look like ``'0.1fig'``.
If not provided we try to get the figure from ``axes.figure``.
width : bool, optional
Whether to use the width or height for the axes and figure
relative coordinates.
"""
# Scales for converting physical units to inches
fontsize_small = _not_none(fontsize, rc_matplotlib['font.size']) # always absolute
fontsize_small = _fontsize_to_pt(fontsize_small)
fontsize_large = _not_none(fontsize, rc_matplotlib['axes.titlesize'])
fontsize_large = _fontsize_to_pt(fontsize_large)
unit_dict = UNIT_DICT.copy()
unit_dict.update(
{
'em': fontsize_small / 72.0,
'en': 0.5 * fontsize_small / 72.0,
'Em': fontsize_large / 72.0,
'En': 0.5 * fontsize_large / 72.0,
}
)
# Scales for converting display units to inches
# WARNING: In ipython shell these take the value 'figure'
if not isinstance(rc_matplotlib['figure.dpi'], str):
unit_dict['px'] = 1 / rc_matplotlib['figure.dpi'] # once generated by backend
if not isinstance(rc_matplotlib['savefig.dpi'], str):
unit_dict['pp'] = 1 / rc_matplotlib['savefig.dpi'] # once 'printed' i.e. saved
# Scales relative to axes and figure objects
if axes is not None and hasattr(axes, '_get_size_inches'): # proplot axes
unit_dict['ax'] = axes._get_size_inches()[1 - int(width)]
if figure is None:
figure = getattr(axes, 'figure', None)
if figure is not None and hasattr(figure, 'get_size_inches'):
unit_dict['fig'] = figure.get_size_inches()[1 - int(width)]
# Scale for converting inches to arbitrary other unit
if numeric is None and dest is None:
numeric = dest = 'in'
elif numeric is None:
numeric = dest
elif dest is None:
dest = numeric
options = 'Valid units are ' + ', '.join(map(repr, unit_dict)) + '.'
try:
nscale = unit_dict[numeric]
except KeyError:
raise ValueError(f'Invalid numeric units {numeric!r}. ' + options)
try:
dscale = unit_dict[dest]
except KeyError:
raise ValueError(f'Invalid destination units {dest!r}. ' + options)
# Convert units for each value in list
result = []
singleton = not np.iterable(value) or isinstance(value, str)
for val in (value,) if singleton else value:
# Silently pass None
if val is None:
result.append(val)
continue
# Get unit string
if isinstance(val, Real):
number, units = val, None
elif isinstance(val, str):
regex = UNIT_REGEX.match(val)
if regex:
number, units = regex.groups() # second group is exponential
else:
raise ValueError(f'Invalid unit size spec {val!r}.')
else:
raise ValueError(f'Invalid unit size spec {val!r}.')
# Convert with units
if not units:
result.append(float(number) * nscale / dscale)
elif units in unit_dict:
result.append(float(number) * unit_dict[units] / dscale)
else:
raise ValueError(f'Invalid input units {units!r}. ' + options)
return result[0] if singleton else result
# Deprecations
shade, saturate = warnings._rename_objs(
'0.6.0',
shade=scale_luminance,
saturate=scale_saturation,
)
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4