#!/usr/bin/env python3
"""
The constructor functions used to build class instances from simple shorthand arguments.
"""
# NOTE: These functions used to be in separate files like crs.py and
# ticker.py but makes more sense to group them together to ensure usage is
# consistent and so online documentation is easier to understand. Also in
# future version classes will not be imported into top-level namespace. This
# change will be easier to do with all constructor functions in separate file.
# NOTE: Used to include the raw variable names that define string keys as
# part of documentation, but this is redundant and pollutes the namespace.
# User should just inspect docstrings, use trial-error, or see online tables.
import os
import re
from functools import partial
from numbers import Number
import cycler
import matplotlib.colors as mcolors
import matplotlib.dates as mdates
import matplotlib.projections.polar as mpolar
import matplotlib.scale as mscale
import matplotlib.ticker as mticker
import numpy as np
from . import colors as pcolors
from . import crs as pcrs
from . import scale as pscale
from . import ticker as pticker
from .config import rc
from .internals import ic # noqa: F401
from .internals import (
_not_none,
_pop_props,
_version,
_version_cartopy,
_version_mpl,
warnings,
)
from .utils import to_rgba
try:
from mpl_toolkits.basemap import Basemap
except ImportError:
Basemap = object
try:
import cartopy.crs as ccrs
import cartopy.mpl.ticker as cticker
from cartopy.crs import CRS
except ModuleNotFoundError:
CRS = ccrs = cticker = object
__all__ = [
'Colormap', 'Colors', 'Cycle', 'Norm',
'Formatter', 'Locator', 'Scale', 'Proj',
]
# Dictionary of possible normalizers. See `Norm` for a table.
NORMS = {
'none': mcolors.NoNorm,
'null': mcolors.NoNorm,
'div': pcolors.DivergingNorm,
'diverging': pcolors.DivergingNorm,
'segmented': pcolors.LinearSegmentedNorm,
'log': mcolors.LogNorm,
'linear': mcolors.Normalize,
'power': mcolors.PowerNorm,
'symlog': mcolors.SymLogNorm,
'zero': pcolors.DivergingNorm, # deprecated
'midpoint': pcolors.DivergingNorm, # deprecated
'segments': pcolors.LinearSegmentedNorm, # deprecated
}
if hasattr(mcolors, 'TwoSlopeNorm'):
NORMS['twoslope'] = mcolors.TwoSlopeNorm
# Mapping of strings to `~matplotlib.ticker.Locator` classes. See
# `Locator` for a table."""
LOCATORS = {
'none': mticker.NullLocator,
'null': mticker.NullLocator,
'auto': mticker.AutoLocator,
'log': mticker.LogLocator,
'maxn': mticker.MaxNLocator,
'linear': mticker.LinearLocator,
'multiple': mticker.MultipleLocator,
'fixed': mticker.FixedLocator,
'index': mticker.IndexLocator,
'symlog': mticker.SymmetricalLogLocator,
'logit': mticker.LogitLocator,
'minor': mticker.AutoMinorLocator,
'date': mdates.AutoDateLocator,
'microsecond': mdates.MicrosecondLocator,
'second': mdates.SecondLocator,
'minute': mdates.MinuteLocator,
'hour': mdates.HourLocator,
'day': mdates.DayLocator,
'weekday': mdates.WeekdayLocator,
'month': mdates.MonthLocator,
'year': mdates.YearLocator,
'lon': partial(pticker.LongitudeLocator, dms=False),
'lat': partial(pticker.LatitudeLocator, dms=False),
'deglon': partial(pticker.LongitudeLocator, dms=False),
'deglat': partial(pticker.LatitudeLocator, dms=False),
}
if _version_cartopy >= _version('0.18'):
# NOTE: This only makes sense when paired with degree-minute-second formatter
# NOTE: We copied cartopy locators because they are short and necessary
# for determining both cartopy and basemap tick locations. We did *not* copy
# formatter because they are long and we have nice, simpler alternatives of
# deglon and deglat.
LOCATORS['dms'] = partial(pticker._DegreeLocator, dms=True)
LOCATORS['dmslon'] = partial(pticker.LongitudeLocator, dms=True)
LOCATORS['dmslat'] = partial(pticker.LatitudeLocator, dms=True)
if hasattr(mpolar, 'ThetaLocator'):
LOCATORS['theta'] = mpolar.ThetaLocator
# Mapping of strings to `~matplotlib.ticker.Formatter` classes. See
# `Formatter` for a table.
# NOTE: Critical to use SimpleFormatter for cardinal formatters rather than
# AutoFormatter because latter fails with Basemap formatting.
# NOTE: Define cartopy longitude/latitude formatters with dms=True because that
# is their distinguishing feature relative to proplot formatter.
FORMATTERS = { # note default LogFormatter uses ugly e+00 notation
'auto': pticker.AutoFormatter,
'frac': pticker.FracFormatter,
'sci': pticker.SciFormatter,
'sigfig': pticker.SigFigFormatter,
'simple': pticker.SimpleFormatter,
'date': mdates.AutoDateFormatter,
'datestr': mdates.DateFormatter,
'scalar': mticker.ScalarFormatter,
'none': mticker.NullFormatter,
'null': mticker.NullFormatter,
'func': mticker.FuncFormatter,
'strmethod': mticker.StrMethodFormatter,
'formatstr': mticker.FormatStrFormatter,
'log': mticker.LogFormatterSciNotation, # NOTE: this is subclass of Mathtext class
'logit': mticker.LogitFormatter,
'eng': mticker.EngFormatter,
'percent': mticker.PercentFormatter,
'index': pticker._IndexFormatter,
'e': partial(pticker.FracFormatter, symbol=r'$e$', number=np.e),
'pi': partial(pticker.FracFormatter, symbol=r'$\pi$', number=np.pi),
'tau': partial(pticker.FracFormatter, symbol=r'$\tau$', number=2 * np.pi),
'lat': partial(pticker.SimpleFormatter, negpos='SN'),
'lon': partial(pticker.SimpleFormatter, negpos='WE', wraprange=(-180, 180)),
'deg': partial(pticker.SimpleFormatter, suffix='\N{DEGREE SIGN}'),
'deglat': partial(pticker.SimpleFormatter, negpos='SN', suffix='\N{DEGREE SIGN}'),
'deglon': partial(pticker.SimpleFormatter, negpos='WE', suffix='\N{DEGREE SIGN}', wraprange=(-180, 180)), # noqa: E501
'math': mticker.LogFormatterMathtext, # deprecated (use SciNotation subclass)
}
if _version_cartopy >= _version('0.18'):
# NOTE: Will raise error when you try to use these without cartopy >= 0.18
FORMATTERS['dms'] = partial(pticker._DegreeFormatter, dms=True)
FORMATTERS['dmslon'] = partial(pticker._LongitudeFormatter, dms=True)
FORMATTERS['dmslat'] = partial(pticker._LatitudeFormatter, dms=True)
if hasattr(mpolar, 'ThetaFormatter'):
FORMATTERS['theta'] = mpolar.ThetaFormatter
if hasattr(mdates, 'ConciseDateFormatter'):
FORMATTERS['concise'] = mdates.ConciseDateFormatter
# The registered scale names and their associated
# `~matplotlib.scale.ScaleBase` classes. See `Scale` for a table.
SCALES = mscale._scale_mapping
SCALE_PRESETS = {
'quadratic': ('power', 2,),
'cubic': ('power', 3,),
'quartic': ('power', 4,),
'height': ('exp', np.e, -1 / 7, 1013.25, True),
'pressure': ('exp', np.e, -1 / 7, 1013.25, False),
'db': ('exp', 10, 1, 0.1, True),
'idb': ('exp', 10, 1, 0.1, False),
'np': ('exp', np.e, 1, 1, True),
'inp': ('exp', np.e, 1, 1, False),
}
mscale.register_scale(pscale.CutoffScale)
mscale.register_scale(pscale.ExpScale)
mscale.register_scale(pscale.LogScale)
mscale.register_scale(pscale.LinearScale)
mscale.register_scale(pscale.LogitScale)
mscale.register_scale(pscale.FuncScale)
mscale.register_scale(pscale.PowerScale)
mscale.register_scale(pscale.SymmetricalLogScale)
mscale.register_scale(pscale.InverseScale)
mscale.register_scale(pscale.SineLatitudeScale)
mscale.register_scale(pscale.MercatorLatitudeScale)
# Default keyword args for `~mpl_toolkits.basemap.Basemap` projections.
# `~mpl_toolkits.basemap` will raise an error if you don't provide them,
# so ProPlot imposes some sensible default behavior.
BASEMAP_KW_DEFAULTS = {
'eck4': {'lon_0': 0},
'geos': {'lon_0': 0},
'hammer': {'lon_0': 0},
'moll': {'lon_0': 0},
'kav7': {'lon_0': 0},
'sinu': {'lon_0': 0},
'vandg': {'lon_0': 0},
'mbtfpq': {'lon_0': 0},
'robin': {'lon_0': 0},
'ortho': {'lon_0': 0, 'lat_0': 0},
'nsper': {'lon_0': 0, 'lat_0': 0},
'aea': {'lon_0': 0, 'lat_0': 90, 'width': 15000e3, 'height': 15000e3},
'eqdc': {'lon_0': 0, 'lat_0': 90, 'width': 15000e3, 'height': 15000e3},
'cass': {'lon_0': 0, 'lat_0': 90, 'width': 15000e3, 'height': 15000e3},
'gnom': {'lon_0': 0, 'lat_0': 90, 'width': 15000e3, 'height': 15000e3},
'poly': {'lon_0': 0, 'lat_0': 0, 'width': 10000e3, 'height': 10000e3},
'npaeqd': {'lon_0': 0, 'boundinglat': 10}, # NOTE: everything breaks if you
'nplaea': {'lon_0': 0, 'boundinglat': 10}, # try to set boundinglat to zero
'npstere': {'lon_0': 0, 'boundinglat': 10},
'spaeqd': {'lon_0': 0, 'boundinglat': -10},
'splaea': {'lon_0': 0, 'boundinglat': -10},
'spstere': {'lon_0': 0, 'boundinglat': -10},
'lcc': {
'lon_0': 0, 'lat_0': 40, 'lat_1': 35, 'lat_2': 45, # use cartopy defaults
'width': 20000e3, 'height': 15000e3
},
'tmerc': {
'lon_0': 0, 'lat_0': 0, 'width': 10000e3, 'height': 10000e3
},
'merc': {
'llcrnrlat': -80, 'urcrnrlat': 84, 'llcrnrlon': -180, 'urcrnrlon': 180
},
'omerc': {
'lat_0': 0, 'lon_0': 0, 'lat_1': -10, 'lat_2': 10,
'lon_1': 0, 'lon_2': 0, 'width': 10000e3, 'height': 10000e3
},
}
BASEMAP_PROJ_ALIASES = { # aliases to basemap naming conventions
'eqc': 'cyl',
'pcarree': 'cyl',
}
# Mapping of "projection names" to cartopy `~cartopy.crs.Projection` classes.
CARTOPY_PROJS = {}
if ccrs is not object:
CARTOPY_PROJS.update({
'aitoff': pcrs.Aitoff,
'hammer': pcrs.Hammer,
'kav7': pcrs.KavrayskiyVII,
'wintri': pcrs.WinkelTripel,
'npgnom': pcrs.NorthPolarGnomonic,
'spgnom': pcrs.SouthPolarGnomonic,
'npaeqd': pcrs.NorthPolarAzimuthalEquidistant,
'spaeqd': pcrs.SouthPolarAzimuthalEquidistant,
'nplaea': pcrs.NorthPolarLambertAzimuthalEqualArea,
'splaea': pcrs.SouthPolarLambertAzimuthalEqualArea,
})
CARTOPY_PROJS_UNAVAIL = {
'aea': 'AlbersEqualArea',
'aeqd': 'AzimuthalEquidistant',
'cyl': 'PlateCarree', # only basemap name not matching PROJ
'eck1': 'EckertI',
'eck2': 'EckertII',
'eck3': 'EckertIII',
'eck4': 'EckertIV',
'eck5': 'EckertV',
'eck6': 'EckertVI',
'eqc': 'PlateCarree', # actual PROJ name
'eqdc': 'EquidistantConic',
'eqearth': 'EqualEarth', # better looking Robinson; not in basemap
'euro': 'EuroPP', # Europe; not in basemap or PROJ
'geos': 'Geostationary',
'gnom': 'Gnomonic',
'igh': 'InterruptedGoodeHomolosine', # not in basemap
'laea': 'LambertAzimuthalEqualArea',
'lcc': 'LambertConformal',
'lcyl': 'LambertCylindrical', # not in basemap or PROJ
'merc': 'Mercator',
'mill': 'Miller',
'moll': 'Mollweide',
'npstere': 'NorthPolarStereo', # np/sp stuff not in PROJ
'nsper': 'NearsidePerspective',
'ortho': 'Orthographic',
'osgb': 'OSGB', # UK; not in basemap or PROJ
'osni': 'OSNI', # Ireland; not in basemap or PROJ
'pcarree': 'PlateCarree', # common alternate name
'robin': 'Robinson',
'rotpole': 'RotatedPole',
'sinu': 'Sinusoidal',
'spstere': 'SouthPolarStereo',
'stere': 'Stereographic',
'tmerc': 'TransverseMercator',
'utm': 'UTM', # not in basemap
}
for _key, _cls in list(CARTOPY_PROJS_UNAVAIL.items()):
if hasattr(ccrs, _cls):
CARTOPY_PROJS[_key] = getattr(ccrs, _cls)
del CARTOPY_PROJS_UNAVAIL[_key]
if CARTOPY_PROJS_UNAVAIL:
warnings._warn_proplot(
'Cartopy projection(s) '
+ ', '.join(map(repr, CARTOPY_PROJS_UNAVAIL.values()))
+ 'are unavailable. Consider updating to cartopy >= 0.17.0.'
)
CARTOPY_KW_ALIASES = { # use PROJ shorthands instead of verbose cartopy names
'lat_0': 'central_latitude',
'lon_0': 'central_longitude',
'lat_min': 'min_latitude',
'lat_max': 'max_latitude',
}
# Resolution aliases
# NOTE: Maximum basemap resolutions are much finer than cartopy
CARTOPY_RESOS = {
'lo': '110m',
'med': '50m',
'hi': '10m',
'x-hi': '10m', # extra high
'xx-hi': '10m', # extra extra high
}
BASEMAP_RESOS = {
'lo': 'c', # coarse
'med': 'l',
'hi': 'i',
'x-hi': 'h',
'xx-hi': 'f', # fine
}
# Geographic feature properties
CARTOPY_FEATURES = { # positional arguments passed to NaturalEarthFeature
'land': ('physical', 'land'),
'ocean': ('physical', 'ocean'),
'lakes': ('physical', 'lakes'),
'coast': ('physical', 'coastline'),
'rivers': ('physical', 'rivers_lake_centerlines'),
'borders': ('cultural', 'admin_0_boundary_lines_land'),
'innerborders': ('cultural', 'admin_1_states_provinces_lakes'),
}
BASEMAP_FEATURES = { # names of relevant basemap methods
'land': 'fillcontinents',
'coast': 'drawcoastlines',
'rivers': 'drawrivers',
'borders': 'drawcountries',
'innerborders': 'drawstates',
}
[docs]def Colors(*args, **kwargs):
"""
Pass all arguments to `Cycle` and return the list of colors from
the resulting `~cycler.Cycler` object.
See also
--------
cycler.Cycler
Cycle
"""
cycle = Cycle(*args, **kwargs)
return list(dict_['color'] for dict_ in cycle)
def _modify_colormap(cmap, *, cut, left, right, reverse, shift, alpha, samples):
"""
Modify colormap using a variety of methods.
"""
if cut is not None or left is not None or right is not None:
if isinstance(cmap, pcolors.ListedColormap):
if cut is not None:
warnings._warn_proplot(
"Invalid argument 'cut' for ListedColormap. Ignoring."
)
cmap = cmap.truncate(left=left, right=right)
else:
cmap = cmap.cut(cut, left=left, right=right)
if reverse:
cmap = cmap.reversed()
if shift is not None:
cmap = cmap.shifted(shift)
if alpha is not None:
cmap = cmap.copy(alpha=alpha)
if samples is not None:
if isinstance(cmap, pcolors.ListedColormap):
cmap = cmap.copy(N=samples)
else:
cmap = cmap.to_listed(samples)
return cmap
[docs]@warnings._rename_kwargs('v0.7', shade='luminance')
def Colormap(
*args, name=None, listmode='perceptual', to_listed=False, cycle=None,
save=False, save_kw=None, **kwargs
):
"""
Generate, retrieve, modify, and/or merge instances of
`~proplot.colors.PerceptuallyUniformColormap`,
`~proplot.colors.LinearSegmentedColormap`, and
`~proplot.colors.ListedColormap`.
Used to interpret the `cmap` and `cmap_kw` arguments
when passed to any plotting method wrapped by
`~proplot.axes.apply_cmap`.
Parameters
----------
*args : colormap-spec
Positional arguments that individually generate colormaps. If more than
one argument is passed, the resulting colormaps are *merged* with
`~proplot.colors.LinearSegmentedColormap.append`
or `~proplot.colors.ListedColormap.append`.
Arguments are interpreted as follows:
* If the argument is a `~matplotlib.colors.Colormap` or a registered
colormap name, nothing more is done.
* If a filename string with valid extension, the colormap data will
be loaded. See `~proplot.config.register_cmaps` and
`~proplot.config.register_cycles`.
* If RGB tuple or color string, a
`~proplot.colors.PerceptuallyUniformColormap` is generated with
`~proplot.colors.PerceptuallyUniformColormap.from_color`. If the
string ends in ``'_r'``, the monochromatic map will be *reversed*,
i.e. will go from dark to light instead of light to dark.
* If list of RGB tuples or color strings, a
`~proplot.colors.PerceptuallyUniformColormap` is generated with
`~proplot.colors.PerceptuallyUniformColormap.from_list`.
* If dictionary, a `~proplot.colors.PerceptuallyUniformColormap` is
generated with `~proplot.colors.PerceptuallyUniformColormap.from_hsl`.
The dictionary should contain the keys ``'hue'``, ``'saturation'``,
``'luminance'``, and optionally ``'alpha'``, or their aliases (see below).
name : str, optional
Name under which the final colormap is registered. It can then be
reused by passing ``cmap='name'`` to plotting functions like
`~matplotlib.axes.Axes.contourf`.
listmode : {'perceptual', 'linear', 'listed'}, optional
Controls how colormaps are generated when you input list(s) of colors.
If ``'perceptual'``, a `~proplot.colors.PerceptuallyUniformColormap`
is generated with `~proplot.colors.PerceptuallyUniformColormap.from_list`.
If ``'linear'``, a `~matplotlib.colors.LinearSegmentedColormap` is
generated with `~matplotlib.colors.LinearSegmentedColormap.from_list`.
If ``'listed'``, a `~matplotlib.colors.ListedColormap` is generated.
Default is ``'perceptual'`` when calling `Colormap` directly and
``'listed'`` when `Colormap` is called by `Cycle`.
samples : int or list of int, optional
For `~proplot.colors.LinearSegmentedColormap`\\ s, this is used to
generate `~proplot.colors.ListedColormap`\\ s with
`~proplot.colors.LinearSegmentedColormap.to_listed`. For
`~proplot.colors.ListedColormap`\\ s, this is used to updates the
number of colors in the cycle. If `samples` is integer, it applies
to the final *merged* colormap. If it is a list of integers,
it applies to each input colormap individually.
to_listed : bool, optional
If ``True``, when the final colormap is a
`~proplot.colors.ListedColormap`, we leave it alone, but when it is a
`~proplot.colors.LinearSegmentedColormap`, we always call
`~proplot.colors.LinearSegmentedColormap.to_listed` with a
default `samples` value of ``10``. This argument is not
necessary if you provide the `samples` argument.
left, right : float or list of float, optional
Truncate the left or right edges of the colormap.
Passed to `~proplot.colors.LinearSegmentedColormap.truncate`.
If float, these apply to the final *merged* colormap. If list
of float, these apply to each input colormap individually.
cut : float or list of float, optional
Cut out the center of the colormap. Passed to
`~proplot.colors.LinearSegmentedColormap.cut`. If float,
this applies to the final *merged* colormap. If list of float,
these apply to each input colormap individually.
reverse : bool or list of bool, optional
Reverse the colormap. Passed to
`~proplot.colors.LinearSegmentedColormap.reversed`. If
float, this applies to the final *merged* colormap. If list of
float, these apply to each input colormap individually.
shift : float or list of float, optional
Cyclically shift the colormap.
Passed to `~proplot.colors.LinearSegmentedColormap.shifted`.
If float, this applies to the final *merged* colormap. If list of
float, these apply to each input colormap individually.
a
Shorthand for `alpha`.
alpha, a : channel-spec or list of channel-spec, optional
The opacity of the colormap or the opacity gradation. Passed to
`proplot.colors.LinearSegmentedColormap.set_alpha`
or `proplot.colors.ListedColormap.set_alpha`. If float, this applies
to the final *merged* colormap. If list of float, these apply to
each colormap individually.
h, s, l, c
Shorthands for `hue`, `luminance`, `saturation`, and `chroma`.
hue, saturation, luminance : channel-spec or list of channel-spec, optional
The channel value(s) used to generate colormaps with
`~proplot.colors.PerceptuallyUniformColormap.from_hsl` and
`~proplot.colors.PerceptuallyUniformColormap.from_color`.
* If you provided no positional arguments, these are used to create
an arbitrary perceptually uniform colormap with
`~proplot.colors.PerceptuallyUniformColormap.from_hsl`. This
is an alternative to passing a dictionary as a positional argument
with `hue`, `saturation`, and `luminance` as dictionary keys (see `args`).
* If you did provide positional arguments, and any of them are
color specifications, these control the look of monochromatic colormaps
generated with `~proplot.colors.PerceptuallyUniformColormap.from_color`.
To use different values for each colormap, pass a list of floats instead
of a scalar. Note the default `luminance` is ``90`` if `to_listed`
is ``True`` and ``100`` otherwise.
chroma
Alias for `saturation`.
cycle : str or list of str, optional
The registered cycle name or a list of colors used to interpret cycle
color strings like ``'C0'`` and ``'C2'``. Default is from the active
property cycler. This lets you make monochromatic colormaps using
colors selected from arbitrary property cycles.
save : bool, optional
Whether to call the colormap/color cycle save method, i.e.
`proplot.colors.LinearSegmentedColormap.save` or
`proplot.colors.ListedColormap.save`.
save_kw : dict-like, optional
Ignored if `save` is ``False``. Passed to the colormap/color cycle
save method, i.e. `proplot.colors.LinearSegmentedColormap.save` or
`proplot.colors.ListedColormap.save`.
Other parameters
----------------
**kwargs
Passed to `proplot.colors.LinearSegmentedColormap.copy`,
`proplot.colors.PerceptuallyUniformColormap.copy`, or
`proplot.colors.ListedColormap.copy`.
Returns
-------
`~matplotlib.colors.Colormap`
A `~proplot.colors.LinearSegmentedColormap` or
`~proplot.colors.ListedColormap` instance.
See also
--------
matplotlib.colors.Colormap
matplotlib.colors.LinearSegmentedColormap
matplotlib.colors.ListedColormap
proplot.axes.apply_cmap
Cycle
"""
# Helper function
# NOTE: Very careful here! Try to support common use cases. For example
# adding opacity gradations to colormaps with Colormap('cmap', alpha=(0.5, 1))
# or sampling maps with Colormap('cmap', samples=np.linspace(0, 1, 11)) should
# be allowable.
# If *args is singleton try to preserve it.
def _pop_modification(key):
value = kwargs.pop(key, None)
if not np.iterable(value) or isinstance(value, str):
values = (None,) * len(args)
elif len(args) == len(value):
values, value = tuple(values), None
elif len(args) == 1: # e.g. Colormap('cmap', alpha=(0.5, 1))
values = (None,)
else:
raise ValueError(
f'Got {len(args)} colormap-specs '
f'but {len(value)} values for {key!r}.'
)
return value, values
# Parse keyword args that can apply to the merged colormap or each
# colormap individually.
hsla = _pop_props(kwargs, 'hsla')
if not args and hsla.keys() - {'alpha'}:
args = (hsla,)
else:
kwargs.update(hsla)
cut, cuts = _pop_modification('cut')
left, lefts = _pop_modification('left')
right, rights = _pop_modification('right')
shift, shifts = _pop_modification('shift')
reverse, reverses = _pop_modification('reverse')
samples, sampless = _pop_modification('samples')
alpha, alphas = _pop_modification('alpha')
luminance, luminances = _pop_modification('luminance')
saturation, saturations = _pop_modification('saturation')
if luminance is not None:
luminances = (luminance,) * len(args)
if saturation is not None:
saturations = (saturation,) * len(args)
# Parse input args
# TODO: Play with using "qualitative" colormaps in realistic examples,
# how to make colormaps cyclic.
if not args:
raise ValueError(
'Colormap() requires either positional arguments '
"or 'hue', 'chroma', 'saturation', and/or 'luminance' keywords."
)
if listmode not in ('listed', 'linear', 'perceptual'):
raise ValueError(
f'Invalid listmode={listmode!r}. Options are: '
"'listed', 'linear', 'perceptual'."
)
# Loop through colormaps
tmp = '_no_name'
cmaps = []
for arg, icut, ileft, iright, ireverse, ishift, isamples, iluminance, isaturation, ialpha in zip( # noqa: E501
args, cuts, lefts, rights, reverses, shifts, sampless, luminances, saturations, alphas # noqa: E501
):
# Load registered colormaps and maps on file
# TODO: Document how 'listmode' also affects loaded files
if isinstance(arg, str):
if '.' in arg and os.path.isfile(arg):
if listmode == 'listed':
arg = pcolors.ListedColormap.from_file(arg)
else:
arg = pcolors.LinearSegmentedColormap.from_file(arg)
else:
try:
arg = pcolors._cmap_database[arg]
except KeyError:
pass
# Convert matplotlib colormaps to subclasses
if isinstance(arg, mcolors.Colormap):
cmap = pcolors._to_proplot_colormap(arg)
# Dictionary of hue/sat/luminance values or 2-tuples
elif isinstance(arg, dict):
cmap = pcolors.PerceptuallyUniformColormap.from_hsl(tmp, **arg)
# List of color tuples or color strings, i.e. iterable of iterables
elif (
not isinstance(arg, str) and np.iterable(arg)
and all(np.iterable(color) for color in arg)
):
colors = [to_rgba(color, cycle=cycle) for color in arg]
if listmode == 'listed':
cmap = pcolors.ListedColormap(colors, tmp)
elif listmode == 'linear':
cmap = pcolors.LinearSegmentedColormap.from_list(tmp, colors)
else:
cmap = pcolors.PerceptuallyUniformColormap.from_list(tmp, colors)
# Monochrome colormap from input color
# NOTE: Do not print color names in error message. Too long to be useful.
else:
jreverse = isinstance(arg, str) and arg[-2:] == '_r'
if jreverse:
arg = arg[:-2]
try:
color = to_rgba(arg, cycle=cycle)
except (ValueError, TypeError):
message = f'Invalid colormap, color cycle, or color {arg!r}.'
if isinstance(arg, str) and arg[:1] != '#':
message += (
' Options are: '
+ ', '.join(map(repr, pcolors._cmap_database)) + '.'
)
raise ValueError(message)
if to_listed and iluminance is None:
iluminance = 90
cmap = pcolors.PerceptuallyUniformColormap.from_color(
tmp, color, luminance=iluminance, saturation=isaturation
)
ireverse = _not_none(ireverse, False)
ireverse = ireverse ^ jreverse # xor
# Modify the colormap
cmap = _modify_colormap(
cmap, cut=icut, left=ileft, right=iright,
reverse=ireverse, shift=ishift, alpha=ialpha, samples=isamples,
)
cmaps.append(cmap)
# Merge the resulting colormaps
if len(cmaps) > 1: # more than one map and modify arbitrary properties
cmap = cmaps[0].append(*cmaps[1:], **kwargs)
elif kwargs: # modify arbitrary properties
cmap = cmaps[0].copy(**kwargs)
else:
cmap = cmaps[0]
# Modify the colormap
if to_listed and samples is None and isinstance(cmap, pcolors.LinearSegmentedColormap): # noqa: E501
samples = 10
cmap = _modify_colormap(
cmap, cut=cut, left=left, right=right,
reverse=reverse, shift=shift, alpha=alpha, samples=samples
)
# Initialize
if not cmap._isinit:
cmap._init()
# Register the colormap
if name is None:
name = cmap.name # may have been modified by e.g. .shifted()
else:
cmap.name = name
pcolors._cmap_database[name] = cmap
# Save the colormap
if save:
save_kw = save_kw or {}
cmap.save(**save_kw)
return cmap
[docs]def Cycle(*args, N=None, samples=None, name=None, **kwargs):
"""
Generate and merge `~cycler.Cycler` instances in a variety of ways.
Used to interpret the `cycle` and `cycle_kw` arguments when passed to
any plotting method wrapped by `~proplot.axes.apply_cycle`.
If you just want a list of colors instead of a `~cycler.Cycler` instance,
use the `Colors` function. If you want a `~cycler.Cycler` instance that
imposes black as the default color and cycles through properties like
``linestyle`` instead, call this function without any positional arguments.
Parameters
----------
*args : colormap-spec or cycle-spec, optional
Positional arguments control the *colors* in the `~cycler.Cycler`
object. If more than one argument is passed, the resulting cycles are
merged. Arguments are interpreted as follows:
* If a `~cycler.Cycler`, nothing more is done.
* If a list of RGB tuples or color strings, these colors are used.
* If a `~proplot.colors.ListedColormap`, colors from the ``colors``
attribute are used.
* If a string cycle name, that `~proplot.colors.ListedColormap`
is looked up and its ``colors`` attribute is used.
* In all other cases, the argument is passed to `Colormap`, and
colors from the resulting `~proplot.colors.LinearSegmentedColormap`
are used. See the `samples` argument.
If the last positional argument is numeric, it is used for the
`samples` keyword argument.
N
Shorthand for `samples`.
samples : float or list of float, optional
For `~proplot.colors.ListedColormap`\\ s, this is the number of
colors to select. For example, ``Cycle('538', 4)`` returns the first 4
colors of the ``'538'`` color cycle.
For `~proplot.colors.LinearSegmentedColormap`\\ s, this is either a
list of sample coordinates used to draw colors from the map, or an
integer number of colors to draw. If the latter, the sample coordinates
are ``np.linspace(0, 1, samples)``. For example, ``Cycle('Reds', 5)``
divides the ``'Reds'`` colormap into five evenly spaced colors.
lw, ls, d, a, m, ms, mew, mec, mfc
Shorthands for the below keywords.
linewidth, linestyle, dashes, alpha, marker, markersize, markeredgewidth, \
markeredgecolor, markerfacecolor : spec or list of specs, optional
Lists of `~matplotlib.lines.Line2D` properties that can be added to
the `~cycler.Cycler` instance. If the lists have unequal length, they
will be filled to match the length of the longest list. See
`~matplotlib.axes.Axes.set_prop_cycle` for more info on cyclers.
Also see the `line style reference \
<https://matplotlib.org/2.2.5/gallery/lines_bars_and_markers/line_styles_reference.html>`__,
the `marker reference \
<https://matplotlib.org/stable/gallery/lines_bars_and_markers/marker_reference.html>`__,
and the `custom dashes reference \
<https://matplotlib.org/stable/gallery/lines_bars_and_markers/line_demo_dash_control.html>`__.
linewidths, linestyles, dashes, alphas, markers, markersizes, markeredgewidths, \
markeredgecolors, markerfacecolors
Aliases for the above keywords.
Other parameters
----------------
**kwargs
If the input is not already a `~cycler.Cycler` instance, these are passed
to `Colormap` and used to build the `~proplot.colors.ListedColormap` from
which the cycler will draw its colors.
Returns
-------
`~cycler.Cycler`
A cycler instance that can be passed to
`~matplotlib.axes.Axes.set_prop_cycle`.
See also
--------
cycler.Cycler
proplot.axes.apply_cycle
Colormap
"""
# Parse keyword arguments that rotate through other properties
# besides color cycles.
props = _pop_props(kwargs, 'lines')
nprops = 0
samples = _not_none(samples=samples, N=N) # trigger Colormap default
for key, value in tuple(props.items()): # permit in-place modification
if value is None:
return
elif not np.iterable(value) or isinstance(value, str):
value = (value,)
elif len(value) != len(args):
nprops = max(nprops, len(value))
props[key] = list(value) # ensure mutable list
# If args is non-empty, means we want color cycle; otherwise is black
if not args:
props['color'] = [mcolors.to_rgba('k')]
if kwargs:
warnings._warn_proplot(f'Ignoring Cycle() keyword arg(s) {kwargs}.')
# Merge cycler objects
elif all(isinstance(arg, cycler.Cycler) for arg in args):
if kwargs:
warnings._warn_proplot(f'Ignoring Cycle() keyword arg(s) {kwargs}.')
if len(args) == 1:
return args[0]
else:
props = {}
for arg in args:
for key, value in arg.by_key():
if key not in props:
props[key] = []
props[key].extend(value)
return cycler.cycler(**props)
# Get cycler from a colormap
else:
# Get the ListedColormap
if args and isinstance(args[-1], Number):
args, samples = args[:-1], _not_none(samples_positional=args[-1], samples=samples) # noqa: #501
kwargs.setdefault('listmode', 'listed')
kwargs.setdefault('to_listed', True) # triggers default 'samples' value
cmap = Colormap(*args, name=name, samples=samples, **kwargs)
name = _not_none(name, cmap.name)
# Add colors to property dict
nprops = max(nprops, len(cmap.colors))
props['color'] = [ # save the tupled version!
tuple(color) if not isinstance(color, str) else color
for color in cmap.colors
]
# Build cycler, make sure lengths are the same
for key, value in props.items():
if len(value) < nprops: # double back if necessary
value[:] = [value[i % len(value)] for i in range(nprops)]
cycle = cycler.cycler(**props)
cycle.name = _not_none(name, '_no_name')
return cycle
[docs]def Norm(norm, *args, **kwargs):
"""
Return an arbitrary `~matplotlib.colors.Normalize` instance. Used to
interpret the `norm` and `norm_kw` arguments when passed to any plotting
method wrapped by `~proplot.axes.apply_cmap`. See `this tutorial \
<https://matplotlib.org/stable/tutorials/colors/colormapnorms.html>`__
for more info.
Parameters
----------
norm : str or `~matplotlib.colors.Normalize`
The normalizer specification. If a `~matplotlib.colors.Normalize`
instance already, the input argument is simply returned. Otherwise,
`norm` should be a string corresponding to one of the "registered"
colormap normalizers (see below table).
If `norm` is a list or tuple and the first element is a "registered"
normalizer name, subsequent elements are passed to the normalizer class
as positional arguments.
.. _norm_table:
========================== =====================================
Key(s) Class
========================== =====================================
``'null'``, ``'none'`` `~matplotlib.colors.NoNorm`
``'diverging'``, ``'div'`` `~proplot.colors.DivergingNorm`
``'segmented'`` `~proplot.colors.LinearSegmentedNorm`
``'linear'`` `~matplotlib.colors.Normalize`
``'log'`` `~matplotlib.colors.LogNorm`
``'power'`` `~matplotlib.colors.PowerNorm`
``'symlog'`` `~matplotlib.colors.SymLogNorm`
========================== =====================================
Other parameters
----------------
*args, **kwargs
Passed to the `~matplotlib.colors.Normalize` initializer.
Returns
-------
`~matplotlib.colors.Normalize`
A `~matplotlib.colors.Normalize` instance.
See also
--------
matplotlib.colors.Normalize
proplot.axes.apply_cmap
proplot.colors.DiscreteNorm
"""
if isinstance(norm, mcolors.Normalize):
return norm
# Pull out extra args
if np.iterable(norm) and not isinstance(norm, str):
norm, args = norm[0], (*norm[1:], *args)
if not isinstance(norm, str):
raise ValueError(f'Invalid norm name {norm!r}. Must be string.')
# Get class
if norm not in NORMS:
raise ValueError(
f'Unknown normalizer {norm!r}. Options are: '
+ ', '.join(map(repr, NORMS.keys())) + '.'
)
if norm == 'symlog' and not args and 'linthresh' not in kwargs:
kwargs['linthresh'] = 1 # special case, needs argument
return NORMS[norm](*args, **kwargs)
[docs]def Locator(locator, *args, **kwargs):
"""
Return a `~matplotlib.ticker.Locator` instance. This function is used to
interpret the `xlocator`, `xlocator_kw`, `ylocator`, `ylocator_kw`,
`xminorlocator`, `xminorlocator_kw`, `yminorlocator`, and
`yminorlocator_kw` arguments when passed to
`~proplot.axes.CartesianAxes.format`, and the `locator`, `locator_kw`,
`minorlocator`, and `minorlocator_kw` arguments when passed to colorbar
methods wrapped by `~proplot.axes.colorbar_extras`.
Parameters
----------
locator : `~matplotlib.ticker.Locator`, str, float, or list of float
The axis locator specification, interpreted as follows:
* If a `~matplotlib.ticker.Locator` instance already, the input
argument is simply returned.
* If a list of numbers, these points are ticked. Returns a
`~matplotlib.ticker.FixedLocator`.
* If number, this specifies the *step size* between tick locations.
Returns a `~matplotlib.ticker.MultipleLocator`.
Otherwise, `locator` should be a string corresponding to one
of the "registered" locators (see below table). If `locator` is a
list or tuple and the first element is a "registered" locator name,
subsequent elements are passed to the locator class as positional
arguments.
.. _locator_table:
======================= ============================================ =====================================================================================
Key Class Description
======================= ============================================ =====================================================================================
``'null'``, ``'none'`` `~matplotlib.ticker.NullLocator` No ticks
``'auto'`` `~matplotlib.ticker.AutoLocator` Major ticks at sensible locations
``'minor'`` `~matplotlib.ticker.AutoMinorLocator` Minor ticks at sensible locations
``'date'`` `~matplotlib.dates.AutoDateLocator` Default tick locations for datetime axes
``'fixed'`` `~matplotlib.ticker.FixedLocator` Ticks at these exact locations
``'index'`` `~matplotlib.ticker.IndexLocator` Ticks on the non-negative integers
``'linear'`` `~matplotlib.ticker.LinearLocator` Exactly ``N`` ticks encompassing axis limits, spaced as ``numpy.linspace(lo, hi, N)``
``'log'`` `~matplotlib.ticker.LogLocator` For log-scale axes
``'logminor'`` `~matplotlib.ticker.LogLocator` For log-scale axes on the 1st through 9th multiples of each power of the base
``'logit'`` `~matplotlib.ticker.LogitLocator` For logit-scale axes
``'logitminor'`` `~matplotlib.ticker.LogitLocator` For logit-scale axes with ``minor=True`` passed to `~matplotlib.ticker.LogitLocator`
``'maxn'`` `~matplotlib.ticker.MaxNLocator` No more than ``N`` ticks at sensible locations
``'multiple'`` `~matplotlib.ticker.MultipleLocator` Ticks every ``N`` step away from zero
``'symlog'`` `~matplotlib.ticker.SymmetricalLogLocator` For symlog-scale axes
``'symlogminor'`` `~matplotlib.ticker.SymmetricalLogLocator` For symlog-scale axes on the 1st through 9th multiples of each power of the base
``'theta'`` `~matplotlib.projections.polar.ThetaLocator` Like the base locator but default locations are every `numpy.pi`/8 radians
``'year'`` `~matplotlib.dates.YearLocator` Ticks every ``N`` years
``'month'`` `~matplotlib.dates.MonthLocator` Ticks every ``N`` months
``'weekday'`` `~matplotlib.dates.WeekdayLocator` Ticks every ``N`` weekdays
``'day'`` `~matplotlib.dates.DayLocator` Ticks every ``N`` days
``'hour'`` `~matplotlib.dates.HourLocator` Ticks every ``N`` hours
``'minute'`` `~matplotlib.dates.MinuteLocator` Ticks every ``N`` minutes
``'second'`` `~matplotlib.dates.SecondLocator` Ticks every ``N`` seconds
``'microsecond'`` `~matplotlib.dates.MicrosecondLocator` Ticks every ``N`` microseconds
``'lon'``, ``'deglon'`` `~proplot.ticker.LongitudeLocator` Longitude gridlines at sensible decimal locations
``'lat'``, ``'deglat'`` `~proplot.ticker.LatitudeLocator` Latitude gridlines at sensible decimal locations
``'dms'`` `~proplot.ticker._DegreeLocator` Gridlines on nice minute and second intervals
``'dmslon'`` `~proplot.ticker.LongitudeLocator` Longitude gridlines on nice minute and second intervals
``'dmslat'`` `~proplot.ticker.LatitudeLocator` Latitude gridlines on nice minute and second intervals
======================= ============================================ =====================================================================================
Other parameters
----------------
*args, **kwargs
Passed to the `~matplotlib.ticker.Locator` class.
Returns
-------
`~matplotlib.ticker.Locator`
A `~matplotlib.ticker.Locator` instance.
See also
--------
matplotlib.ticker.Locator
proplot.axes.CartesianAxes.format
proplot.axes.PolarAxes.format
proplot.axes.GeoAxes.format
proplot.axes.colorbar_extras
Formatter
""" # noqa
if isinstance(locator, mticker.Locator):
return locator
# Pull out extra args
if np.iterable(locator) and not isinstance(locator, str) and not all(
isinstance(num, Number) for num in locator
):
locator, args = locator[0], (*locator[1:], *args)
# Get the locator
if isinstance(locator, str): # dictionary lookup
# Shorthands and defaults
if locator in ('logminor', 'logitminor', 'symlogminor'):
locator, _ = locator.split('minor')
if locator == 'logit':
kwargs.setdefault('minor', True)
else:
kwargs.setdefault('subs', np.arange(1, 10))
elif locator == 'index':
args = args or (1,)
if len(args) == 1:
args = (*args, 0)
# Lookup
if locator not in LOCATORS:
raise ValueError(
f'Unknown locator {locator!r}. Options are '
+ ', '.join(map(repr, LOCATORS.keys())) + '.'
)
locator = LOCATORS[locator](*args, **kwargs)
elif isinstance(locator, Number): # scalar variable
locator = mticker.MultipleLocator(locator, *args, **kwargs)
elif np.iterable(locator):
locator = mticker.FixedLocator(np.sort(locator), *args, **kwargs)
else:
raise ValueError(f'Invalid locator {locator!r}.')
return locator
[docs]def Scale(scale, *args, **kwargs):
"""
Return a `~matplotlib.scale.ScaleBase` instance. This function is used to
interpret the `xscale`, `xscale_kw`, `yscale`, and `yscale_kw` arguments
when passed to `~proplot.axes.CartesianAxes.format`.
Parameters
----------
scale : `~matplotlib.scale.ScaleBase`, str, or (str, ...)
The axis scale specification. If a `~matplotlib.scale.ScaleBase`
instance already, the input argument is simply returned. Otherwise,
`scale` should be a string corresponding to one of the
"registered" axis scales or axis scale presets (see below table).
If `scale` is a list or tuple and the first element is a
"registered" scale name, subsequent elements are passed to the
scale class as positional arguments.
.. _scale_table:
================= ====================================== ===============================================
Key Class Description
================= ====================================== ===============================================
``'linear'`` `~proplot.scale.LinearScale` Linear
``'log'`` `~proplot.scale.LogScale` Logarithmic
``'symlog'`` `~proplot.scale.SymmetricalLogScale` Logarithmic beyond finite space around zero
``'logit'`` `~proplot.scale.LogitScale` Logistic
``'inverse'`` `~proplot.scale.InverseScale` Inverse
``'function'`` `~proplot.scale.FuncScale` Arbitrary forward and backwards transformations
``'sine'`` `~proplot.scale.SineLatitudeScale` Sine function (in degrees)
``'mercator'`` `~proplot.scale.MercatorLatitudeScale` Mercator latitude function (in degrees)
``'exp'`` `~proplot.scale.ExpScale` Arbitrary exponential function
``'power'`` `~proplot.scale.PowerScale` Arbitrary power function
``'cutoff'`` `~proplot.scale.CutoffScale` Arbitrary piecewise linear transformations
``'quadratic'`` `~proplot.scale.PowerScale` (preset) Quadratic function
``'cubic'`` `~proplot.scale.PowerScale` (preset) Cubic function
``'quartic'`` `~proplot.scale.PowerScale` (preset) Quartic function
``'db'`` `~proplot.scale.ExpScale` (preset) Ratio expressed as `decibels <db_>`_
``'np'`` `~proplot.scale.ExpScale` (preset) Ratio expressed as `nepers <np_>`_
``'idb'`` `~proplot.scale.ExpScale` (preset) `Decibels <db_>`_ expressed as ratio
``'inp'`` `~proplot.scale.ExpScale` (preset) `Nepers <np_>`_ expressed as ratio
``'pressure'`` `~proplot.scale.ExpScale` (preset) Height (in km) expressed linear in pressure
``'height'`` `~proplot.scale.ExpScale` (preset) Pressure (in hPa) expressed linear in height
================= ====================================== ===============================================
.. _db: https://en.wikipedia.org/wiki/Decibel
.. _np: https://en.wikipedia.org/wiki/Neper
Other parameters
----------------
*args, **kwargs
Passed to the `~matplotlib.scale.ScaleBase` class.
Returns
-------
`~matplotlib.scale.ScaleBase`
The scale instance.
See also
--------
matplotlib.scale.ScaleBase
proplot.axes.CartesianAxes.format
proplot.axes.CartesianAxes.dualx
proplot.axes.CartesianAxes.dualy
""" # noqa
# NOTE: Why not try to interpret FuncScale arguments, like when lists
# of numbers are passed to Locator? Because FuncScale *itself* accepts
# ScaleBase classes as arguments... but constructor functions cannot
# do anything but return the class instance upon receiving one.
if isinstance(scale, mscale.ScaleBase):
return scale
# Pull out extra args
if np.iterable(scale) and not isinstance(scale, str):
scale, args = scale[0], (*scale[1:], *args)
if not isinstance(scale, str):
raise ValueError(f'Invalid scale name {scale!r}. Must be string.')
# Get scale preset
if scale in SCALE_PRESETS:
if args or kwargs:
warnings._warn_proplot(
f'Scale {scale!r} is a scale *preset*. Ignoring positional '
'argument(s): {args} and keyword argument(s): {kwargs}. '
)
scale, *args = SCALE_PRESETS[scale]
# Get scale
scale = scale.lower()
if scale in SCALES:
scale = SCALES[scale]
else:
raise ValueError(
f'Unknown scale or preset {scale!r}. Options are '
+ ', '.join(map(repr, list(SCALES) + list(SCALE_PRESETS))) + '.'
)
return scale(*args, **kwargs)
[docs]def Proj(name, basemap=None, **kwargs):
"""
Return a `cartopy.crs.Projection` or `~mpl_toolkits.basemap.Basemap`
instance. Used to interpret the `proj` and `proj_kw` arguments when
passed to `~proplot.ui.subplots`.
Parameters
----------
name : str, `cartopy.crs.Projection`, or `~mpl_toolkits.basemap.Basemap`
The projection name or projection class instance. If the latter, it
is simply returned. If the former, it must correspond to one of the
`PROJ <https://proj.org>`__ projection name shorthands, like in
basemap.
The following table lists the valid projection name shorthands, their
full names (with links to the relevant
`PROJ documentation <https://proj4.org/operations/projections>`__),
and whether they are available in the cartopy and basemap packages.
(added) indicates a projection class that ProPlot has "added"
to cartopy using the cartopy API.
.. _proj_table:
============= =============================================== ========= =======
Key Name Cartopy Basemap
============= =============================================== ========= =======
``'aea'`` `Albers Equal Area <aea_>`_ ✓ ✓
``'aeqd'`` `Azimuthal Equidistant <aeqd_>`_ ✓ ✓
``'aitoff'`` `Aitoff <aitoff_>`_ ✓ (added) ✗
``'cass'`` `Cassini-Soldner <cass_>`_ ✗ ✓
``'cea'`` `Cylindrical Equal Area <cea_>`_ ✗ ✓
``'cyl'`` `Cylindrical Equidistant <eqc_>`_ ✓ ✓
``'eck1'`` `Eckert I <eck1_>`_ ✓ ✗
``'eck2'`` `Eckert II <eck2_>`_ ✓ ✗
``'eck3'`` `Eckert III <eck3_>`_ ✓ ✗
``'eck4'`` `Eckert IV <eck4_>`_ ✓ ✓
``'eck5'`` `Eckert V <eck5_>`_ ✓ ✗
``'eck6'`` `Eckert VI <eck6_>`_ ✓ ✗
``'eqdc'`` `Equidistant Conic <eqdc_>`_ ✓ ✓
``'eqc'`` `Cylindrical Equidistant <eqc_>`_ ✓ ✓
``'eqearth'`` `Equal Earth <eqearth_>`_ ✓ ✗
``'europp'`` Euro PP (Europe) ✓ ✗
``'gall'`` `Gall Stereographic Cylindrical <gall_>`_ ✗ ✓
``'geos'`` `Geostationary <geos_>`_ ✓ ✓
``'gnom'`` `Gnomonic <gnom_>`_ ✓ ✓
``'hammer'`` `Hammer <hammer_>`_ ✓ (added) ✓
``'igh'`` `Interrupted Goode Homolosine <igh_>`_ ✓ ✗
``'kav7'`` `Kavrayskiy VII <kav7_>`_ ✓ (added) ✓
``'laea'`` `Lambert Azimuthal Equal Area <laea_>`_ ✓ ✓
``'lcc'`` `Lambert Conformal <lcc_>`_ ✓ ✓
``'lcyl'`` Lambert Cylindrical ✓ ✗
``'mbtfpq'`` `McBryde-Thomas Flat-Polar Quartic <mbtfpq_>`_ ✗ ✓
``'merc'`` `Mercator <merc_>`_ ✓ ✓
``'mill'`` `Miller Cylindrical <mill_>`_ ✓ ✓
``'moll'`` `Mollweide <moll_>`_ ✓ ✓
``'npaeqd'`` North-Polar Azimuthal Equidistant ✓ (added) ✓
``'npgnom'`` North-Polar Gnomonic ✓ (added) ✗
``'nplaea'`` North-Polar Lambert Azimuthal ✓ (added) ✓
``'npstere'`` North-Polar Stereographic ✓ ✓
``'nsper'`` `Near-Sided Perspective <nsper_>`_ ✓ ✓
``'osni'`` OSNI (Ireland) ✓ ✗
``'osgb'`` OSGB (UK) ✓ ✗
``'omerc'`` `Oblique Mercator <omerc_>`_ ✗ ✓
``'ortho'`` `Orthographic <ortho_>`_ ✓ ✓
``'pcarree'`` `Cylindrical Equidistant <eqc_>`_ ✓ ✓
``'poly'`` `Polyconic <poly_>`_ ✗ ✓
``'rotpole'`` Rotated Pole ✓ ✓
``'sinu'`` `Sinusoidal <sinu_>`_ ✓ ✓
``'spaeqd'`` South-Polar Azimuthal Equidistant ✓ (added) ✓
``'spgnom'`` South-Polar Gnomonic ✓ (added) ✗
``'splaea'`` South-Polar Lambert Azimuthal ✓ (added) ✓
``'spstere'`` South-Polar Stereographic ✓ ✓
``'stere'`` `Stereographic <stere_>`_ ✓ ✓
``'tmerc'`` `Transverse Mercator <tmerc_>`_ ✓ ✓
``'utm'`` `Universal Transverse Mercator <utm_>`_ ✓ ✗
``'vandg'`` `van der Grinten <vandg_>`_ ✗ ✓
``'wintri'`` `Winkel tripel <wintri_>`_ ✓ (added) ✗
============= =============================================== ========= =======
basemap : bool, optional
Whether to use the basemap package as opposed to the cartopy package.
Default is :rc:`basemap`.
lonlim : 2-tuple of float, optional
Alternative way to specify `llcrnrlon` and `urcrnrlon` for basemap
projections.
latlim : 2-tuple of float, optional
Alternative way to specify `llcrnrlat` and `urcrnrlat` for basemap
projections.
Other parameters
----------------
**kwargs
Passed to the `~mpl_toolkits.basemap.Basemap` or
cartopy `~cartopy.crs.Projection` class. For cartopy axes,
ProPlot translates `lon_0` and `lat_0` to `central_longitude` and
`central_latitude`.
Returns
-------
proj : `~mpl_toolkits.basemap.Basemap` or `~cartopy.crs.Projection`
The projection instance.
See also
--------
mpl_toolkits.basemap.Basemap
cartopy.crs.Projection
proplot.ui.subplots
proplot.axes.GeoAxes
proplot.axes.CartopyAxes
proplot.axes.BasemapAxes
References
----------
For more information on map projections, see the
`wikipedia page <https://en.wikipedia.org/wiki/Map_projection>`__ and the
`PROJ <https://proj.org>`__ documentation.
.. _aea: https://proj4.org/operations/projections/aea.html
.. _aeqd: https://proj4.org/operations/projections/aeqd.html
.. _aitoff: https://proj4.org/operations/projections/aitoff.html
.. _cass: https://proj4.org/operations/projections/cass.html
.. _cea: https://proj4.org/operations/projections/cea.html
.. _eqc: https://proj4.org/operations/projections/eqc.html
.. _eck1: https://proj4.org/operations/projections/eck1.html
.. _eck2: https://proj4.org/operations/projections/eck2.html
.. _eck3: https://proj4.org/operations/projections/eck3.html
.. _eck4: https://proj4.org/operations/projections/eck4.html
.. _eck5: https://proj4.org/operations/projections/eck5.html
.. _eck6: https://proj4.org/operations/projections/eck6.html
.. _eqdc: https://proj4.org/operations/projections/eqdc.html
.. _eqc: https://proj4.org/operations/projections/eqc.html
.. _eqearth: https://proj4.org/operations/projections/eqearth.html
.. _gall: https://proj4.org/operations/projections/gall.html
.. _geos: https://proj4.org/operations/projections/geos.html
.. _gnom: https://proj4.org/operations/projections/gnom.html
.. _hammer: https://proj4.org/operations/projections/hammer.html
.. _igh: https://proj4.org/operations/projections/igh.html
.. _kav7: https://proj4.org/operations/projections/kav7.html
.. _laea: https://proj4.org/operations/projections/laea.html
.. _lcc: https://proj4.org/operations/projections/lcc.html
.. _mbtfpq: https://proj4.org/operations/projections/mbtfpq.html
.. _merc: https://proj4.org/operations/projections/merc.html
.. _mill: https://proj4.org/operations/projections/mill.html
.. _moll: https://proj4.org/operations/projections/moll.html
.. _nsper: https://proj4.org/operations/projections/nsper.html
.. _omerc: https://proj4.org/operations/projections/omerc.html
.. _ortho: https://proj4.org/operations/projections/ortho.html
.. _eqc: https://proj4.org/operations/projections/eqc.html
.. _poly: https://proj4.org/operations/projections/poly.html
.. _sinu: https://proj4.org/operations/projections/sinu.html
.. _stere: https://proj4.org/operations/projections/stere.html
.. _tmerc: https://proj4.org/operations/projections/tmerc.html
.. _utm: https://proj4.org/operations/projections/utm.html
.. _vandg: https://proj4.org/operations/projections/vandg.html
.. _wintri: https://proj4.org/operations/projections/wintri.html
""" # noqa
# Class instances
is_crs = CRS is not object and isinstance(name, CRS)
is_basemap = Basemap is not object and isinstance(name, Basemap)
if is_crs or is_basemap:
proj = name
proj._proj_package = 'cartopy' if is_crs else 'basemap'
if basemap is not None:
kwargs['basemap'] = basemap
if kwargs:
warnings._warn_proplot(f'Ignoring Proj() keyword arg(s): {kwargs!r}.')
# Invalid
elif not isinstance(name, str):
raise ValueError(
f'Unexpected Proj() argument {name!r}. '
'Must be name, mpl_toolkits.basemap.Basemap instance, '
'or cartopy.crs.CRS instance.'
)
# Basemap
elif basemap or basemap is None and rc['basemap']:
# NOTE: Known issue that basemap sometimes produces backwards maps:
# https://stackoverflow.com/q/56299971/4970632
# NOTE: We set rsphere to fix non-conda installed basemap issue:
# https://github.com/matplotlib/basemap/issues/361
# NOTE: Unlike cartopy, basemap resolution is configured on
# initialization and controls *all* features.
import mpl_toolkits.basemap as mbasemap
if _version_mpl >= _version('3.3'):
raise RuntimeError(
'Basemap is no longer maintained and is incompatible with '
'matplotlib >= 3.3. Please use cartopy as your cartographic '
'plotting backend or downgrade to matplotlib <= 3.2.'
)
if 'lonlim' in kwargs:
kwargs['llcrnrlon'], kwargs['urcrnrlon'] = kwargs.pop('lonlim')
if 'latlim' in kwargs:
kwargs['llcrnrlat'], kwargs['urcrnrlat'] = kwargs.pop('latlim')
name = BASEMAP_PROJ_ALIASES.get(name, name)
kwproj = BASEMAP_KW_DEFAULTS.get(name, {}).copy()
kwproj.update(kwargs)
kwproj.setdefault('fix_aspect', True)
if kwproj.get('lon_0', 0) > 0:
# Fix issues with Robinson (and related?) projections
# See: https://stackoverflow.com/questions/56299971/
# Get both this issue *and* 'no room for axes' issue
kwproj['lon_0'] -= 360
if name[:2] in ('np', 'sp'):
kwproj.setdefault('round', True)
if name == 'geos':
kwproj.setdefault('rsphere', (6378137.00, 6356752.3142))
reso = _not_none(
reso=kwproj.pop('reso', None),
resolution=kwproj.pop('resolution', None),
default=rc['reso']
)
try:
reso = BASEMAP_RESOS[reso]
except KeyError:
raise ValueError(
f'Invalid resolution {reso!r}. Options are: '
+ ', '.join(map(repr, BASEMAP_RESOS)) + '.'
)
kwproj.update({'resolution': reso, 'projection': name})
proj = mbasemap.Basemap(**kwproj)
proj._proj_package = 'basemap'
# Cartopy
else:
import cartopy.crs # noqa: F401
kwproj = {
CARTOPY_KW_ALIASES.get(key, key): value
for key, value in kwargs.items()
}
crs = CARTOPY_PROJS.get(name, None)
if name == 'geos': # fix common mistake
kwproj.pop('central_latitude', None)
if 'boundinglat' in kwproj:
raise ValueError(
'"boundinglat" must be passed to the ax.format() command '
'for cartopy axes.'
)
if crs is None:
raise ValueError(
f'Unknown projection {name!r}. Options are: '
+ ', '.join(map(repr, CARTOPY_PROJS.keys())) + '.'
)
proj = crs(**kwproj)
proj._proj_package = 'cartopy'
return proj