Source code for proplot.utils

#!/usr/bin/env python3
Simple tools used in various places across this package.
import re
import time
import functools
import warnings
import numpy as np
from matplotlib import rcParams
from numbers import Number, Integral
    from icecream import ic
except ImportError:  # graceful fallback if IceCream isn't installed
    ic = lambda *a: None if not a else (a[0] if len(a) == 1 else a)  # noqa
__all__ = ['arange', 'edges', 'edges2d', 'units']
BENCHMARK = False  # change this to turn on benchmarking
NUMBER = re.compile('^([-+]?[0-9._]+([eE][-+]?[0-9_]+)?)(.*)$')

class _benchmark(object):
    """Context object for timing arbitrary blocks of code."""
    def __init__(self, message):
        self.message = message

    def __enter__(self):
        if BENCHMARK:
            self.time = time.perf_counter()

    def __exit__(self, *args):
        if BENCHMARK:
            print(f'{self.message}: {time.perf_counter() - self.time}s')

class _setstate(object):
    """Temporarily modify attribute(s) for an arbitrary object."""
    def __init__(self, obj, **kwargs):
        self._obj = obj
        self._kwargs = kwargs
        self._kwargs_orig = {
            key: getattr(obj, key) for key in kwargs if hasattr(obj, key)

    def __enter__(self):
        for key, value in self._kwargs.items():
            setattr(self._obj, key, value)

    def __exit__(self, *args):
        for key in self._kwargs.keys():
            if key in self._kwargs_orig:
                setattr(self._obj, key, self._kwargs_orig[key])
                delattr(self._obj, key)

def _counter(func):
    """A decorator that counts and prints the cumulative time a function
    has benn running. See `this link \
    def decorator(*args, **kwargs):
        if BENCHMARK:
            t = time.perf_counter()
        res = func(*args, **kwargs)
        if BENCHMARK:
            decorator.time += (time.perf_counter() - t)
            decorator.count += 1
            print(f'{func.__name__}() cumulative time: {decorator.time}s '
                  f'({decorator.count} calls)')
        return res
    decorator.time = 0
    decorator.count = 0  # initialize
    return decorator

def _timer(func):
    """Decorator that prints the time a function takes to execute.
    def decorator(*args, **kwargs):
        if BENCHMARK:
            t = time.perf_counter()
        res = func(*args, **kwargs)
        if BENCHMARK:
            print(f'{func.__name__}() time: {time.perf_counter()-t}s')
        return res
    return decorator

def _format_warning(message, category, filename, lineno, line=None):
    """Simple format for warnings issued by ProPlot. See the
    `internal warning call signature \
    and the `default warning source code \
    return f'{filename}:{lineno}: ProPlotWarning: {message}\n'  # needs newline

def _warn_proplot(message):
    """*Temporarily* apply the `_format_warning` monkey patch and emit the
    warning. Do not want to affect warnings emitted by other modules."""
    with _setstate(warnings, formatwarning=_format_warning):

def _notNone(*args, names=None):
    """Return the first non-``None`` value. This is used with keyword arg
    aliases and for setting default values. Ugly name but clear purpose. Pass
    the `names` keyword arg to issue warning if multiple args were passed. Must
    be list of non-empty strings."""
    if names is None:
        for arg in args:
            if arg is not None:
                return arg
        return arg  # last one
        first = None
        kwargs = {}
        if len(names) != len(args) - 1:
            raise ValueError(
                f'Need {len(args)+1} names for {len(args)} args, '
                f'but got {len(names)} names.'
        names = [*names, '']
        for name, arg in zip(names, args):
            if arg is not None:
                if first is None:
                    first = arg
                if name:
                    kwargs[name] = arg
        if len(kwargs) > 1:
                f'Got conflicting or duplicate keyword args: {kwargs}. '
                'Using the first one.'
        return first

[docs]def arange(min_, *args): """Identical to `numpy.arange` but with inclusive endpoints. For example, ``plot.arange(2,4)`` returns ``np.array([2,3,4])`` instead of ``np.array([2,3])``. This command is useful for generating lists of tick locations or colorbar level boundaries.""" # 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) * 1 # 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_ += np.sign(step) * (step / 2) return np.arange(min_, max_, step)
[docs]def edges(Z, axis=-1): """ Calculate the approximate "edge" values along an arbitrary axis, given "center" values. This is used internally to calculate graticule edges when you supply centers to `~matplotlib.axes.Axes.pcolor` or `~matplotlib.axes.Axes.pcolormesh` and to calculate colormap levels when you supply centers to any method wrapped by `~proplot.wrappers.cmap_changer`. Parameters ---------- Z : array-like Array of any shape or size. Generally, should be monotonically increasing or decreasing along `axis`. 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. """ Z = np.asarray(Z) Z = np.swapaxes(Z, axis, -1) Z = np.concatenate(( Z[..., :1] - (Z[..., 1] - Z[..., 0]) / 2, (Z[..., 1:] + Z[..., :-1]) / 2, Z[..., -1:] + (Z[..., -1] - Z[..., -2]) / 2, ), axis=-1) return np.swapaxes(Z, axis, -1)
[docs]def edges2d(Z): """ Like `edges` but for 2d arrays. The size of both axes are increased by one. This is used internally to calculate graitule edges when you supply centers to `~matplotlib.axes.Axes.pcolor` or `~matplotlib.axes.Axes.pcolormesh`. Parameters ---------- Z : array-like A 2d array. Returns ------- `~numpy.ndarray` Array of "edge" coordinates. """ 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 Zb[1:-1, 1:-1] = 0.25 * ( Z[1:, 1:] + Z[:-1, 1:] + Z[1:, :-1] + Z[:-1, :-1] ) # Lower and upper Zb[0] += edges(1.5 * Z[0] - 0.5 * Z[1]) Zb[-1] += edges(1.5 * Z[-1] - 0.5 * Z[-2]) # Left and right Zb[:, 0] += edges(1.5 * Z[:, 0] - 0.5 * Z[:, 1]) Zb[:, -1] += edges(1.5 * Z[:, -1] - 0.5 * Z[:, -2]) # Corners Zb[[0, 0, -1, -1], [0, -1, -1, 0]] *= 0.5 return Zb
[docs]def units(value, units='in', axes=None, figure=None, width=True): """ Convert values and lists of 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 list thereof A size specifier or *list thereof*. If numeric, nothing is done. If string, it is converted to `units` units. The string should look like ``'123.456unit'``, where the number is the magnitude and ``'unit'`` is one of the following. ========= ========================================================================================= Key Description ========= ========================================================================================= ``'m'`` Meters ``'cm'`` Centimeters ``'mm'`` Millimeters ``'ft'`` Feet ``'in'`` Inches ``'pt'`` `Points <>`__ (1/72 inches) ``'pc'`` `Pica <>`__ (1/6 inches) ``'px'`` Pixels on screen, uses dpi of :rcraw:`figure.dpi` ``'pp'`` Pixels once printed, uses dpi of :rcraw:`savefig.dpi` ``'em'`` `Em square <>`__ for :rcraw:`font.size` ``'en'`` `En square <>`__ for :rcraw:`font.size` ``'Em'`` `Em square <>`__ for :rcraw:`axes.titlesize` ``'En'`` `En square <>`__ for :rcraw:`axes.titlesize` ``'ax'`` Axes relative units. Not always available. ``'fig'`` Figure relative units. Not always available. ``'ly'`` Light years ;) ========= ========================================================================================= units : str, optional The destination units. Default is inches, i.e. ``'in'``. 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 ``None`` 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. """ # noqa # Font unit scales # NOTE: Delay font_manager import, because want to avoid rebuilding font # cache, which means import must come after TTFPATH added to environ # by styletools.register_fonts()! small = rcParams['font.size'] # must be absolute large = rcParams['axes.titlesize'] if isinstance(large, str): import matplotlib.font_manager as mfonts # error will be raised somewhere else if string name is invalid! scale = mfonts.font_scalings.get(large, 1) large = small * scale # Scales for converting physical units to inches unit_dict = { 'in': 1.0, 'm': 39.37, 'ft': 12.0, 'cm': 0.3937, 'mm': 0.03937, 'pt': 1 / 72.0, 'pc': 1 / 6.0, 'em': small / 72.0, 'en': 0.5 * small / 72.0, 'Em': large / 72.0, 'En': 0.5 * large / 72.0, 'ly': 3.725e+17, } # Scales for converting display units to inches # WARNING: In ipython shell these take the value 'figure' if not isinstance(rcParams['figure.dpi'], str): # once generated by backend unit_dict['px'] = 1 / rcParams['figure.dpi'] if not isinstance(rcParams['savefig.dpi'], str): # once 'printed' i.e. saved unit_dict['pp'] = 1 / rcParams['savefig.dpi'] # 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'): # proplot axes unit_dict['fig'] = figure.get_size_inches()[1 - int(width)] # Scale for converting inches to arbitrary other unit try: scale = unit_dict[units] except KeyError: raise ValueError( f'Invalid destination units {units!r}. Valid units are ' + ', '.join(map(repr, unit_dict.keys())) + '.' ) # 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): if val is None or isinstance(val, Number): result.append(val) continue elif not isinstance(val, str): raise ValueError( f'Size spec must be string or number or list thereof. ' f'Got {value!r}.' ) regex = NUMBER.match(val) if not regex: raise ValueError( f'Invalid size spec {val!r}. Valid units are ' + ', '.join(map(repr, unit_dict.keys())) + '.' ) number, _, units = regex.groups() # second group is exponential try: result.append( float(number) * (unit_dict[units] / scale if units else 1)) except (KeyError, ValueError): raise ValueError( f'Invalid size spec {val!r}. Valid units are ' + ', '.join(map(repr, unit_dict.keys())) + '.' ) if singleton: result = result[0] return result