# Copyright Iris contributors
#
# This file is part of Iris and is released under the BSD license.
# See LICENSE in the root of the repository for full licensing details.
"""High-level plotting extensions to :mod:`iris.plot`.
These routines work much like their :mod:`iris.plot` counterparts, but they
automatically add a plot title, axis titles, and a colour bar when appropriate.
See also: :ref:`matplotlib <matplotlib:users-guide-index>`.
"""
import cf_units
import matplotlib.pyplot as plt
import iris.config
import iris.coords
import iris.plot as iplt
def _use_symbol(units):
# For non-time units use the shortest unit representation.
# E.g. prefer 'K' over 'kelvin', but not '0.0174532925199433 rad'
# over 'degrees'
return (
not units.is_time()
and not units.is_time_reference()
and len(units.symbol) < len(str(units))
)
def _title(cube_or_coord, with_units):
if cube_or_coord is None or isinstance(cube_or_coord, int):
title = ""
else:
title = cube_or_coord.name().replace("_", " ").capitalize()
units = cube_or_coord.units
if with_units and not (
units.is_unknown()
or units.is_no_unit()
or units == cf_units.Unit("1")
or units.is_time_reference()
):
if _use_symbol(units):
units = units.symbol
title += " / {}".format(units)
return title
def _label(cube, mode, result=None, ndims=2, coords=None, axes=None, colorbar=True):
"""Put labels on the current plot using the given cube."""
if axes is None:
axes = plt.gca()
axes.set_title(_title(cube, with_units=False))
# optional colorbar
if colorbar and result is not None:
draw_edges = mode == iris.coords.POINT_MODE
bar = plt.colorbar(
result, ax=axes, orientation="horizontal", drawedges=draw_edges
)
has_known_units = not (cube.units.is_unknown() or cube.units.is_no_unit())
if has_known_units and cube.units != cf_units.Unit("1"):
# Use shortest unit representation for anything other than time
if _use_symbol(cube.units):
bar.set_label(cube.units.symbol)
else:
bar.set_label(cube.units)
# Remove the tick which is put on the colorbar by default.
bar.ax.tick_params(length=0)
if coords is None:
plot_defn = iplt._get_plot_defn(cube, mode, ndims)
else:
plot_defn = iplt._get_plot_defn_custom_coords_picked(
cube, coords, mode, ndims=ndims
)
if ndims == 2:
if not iplt._can_draw_map(plot_defn.coords):
axes.set_ylabel(_title(plot_defn.coords[0], with_units=True))
axes.set_xlabel(_title(plot_defn.coords[1], with_units=True))
elif ndims == 1:
axes.set_xlabel(_title(plot_defn.coords[0], with_units=True))
axes.set_ylabel(_title(cube, with_units=True))
else:
msg = "Unexpected number of dimensions ({}) given to _label.".format(ndims)
raise ValueError(msg)
def _label_with_bounds(
cube, result=None, ndims=2, coords=None, axes=None, colorbar=True
):
_label(cube, iris.coords.BOUND_MODE, result, ndims, coords, axes, colorbar)
def _label_with_points(
cube, result=None, ndims=2, coords=None, axes=None, colorbar=True
):
_label(cube, iris.coords.POINT_MODE, result, ndims, coords, axes, colorbar)
def _get_titles(u_object, v_object):
if u_object is None:
u_object = iplt._u_object_from_v_object(v_object)
xlabel = _title(u_object, with_units=True)
ylabel = _title(v_object, with_units=True)
title = ""
if u_object is None:
title = _title(v_object, with_units=False)
elif isinstance(u_object, iris.cube.Cube) and not isinstance(
v_object, iris.cube.Cube
):
title = _title(u_object, with_units=False)
elif isinstance(v_object, iris.cube.Cube) and not isinstance(
u_object, iris.cube.Cube
):
title = _title(v_object, with_units=False)
return xlabel, ylabel, title
def _label_1d_plot(*args, **kwargs):
u_obj, v_obj, _, _, _ = iplt._get_plot_objects(args)
xlabel, ylabel, title = _get_titles(u_obj, v_obj)
axes = kwargs.pop("axes", None)
if len(kwargs) != 0:
msg = "Unexpected kwargs {} given to _label_1d_plot".format(kwargs.keys())
raise ValueError(msg)
if axes is None:
axes = plt.gca()
axes.set_title(title)
axes.set_xlabel(xlabel)
axes.set_ylabel(ylabel)
[docs]
def contour(cube, *args, **kwargs):
"""Draw contour lines on a labelled plot based on the given Cube.
With the basic call signature, contour "level" values are chosen
automatically::
contour(cube)
Supply a number to use *N* automatically chosen levels::
contour(cube, N)
Supply a sequence *V* to use explicitly defined levels::
contour(cube, V)
See :func:`iris.plot.contour` for details of valid keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
coords = kwargs.get("coords")
axes = kwargs.get("axes")
result = iplt.contour(cube, *args, **kwargs)
_label_with_points(cube, coords=coords, axes=axes)
return result
[docs]
def contourf(cube, *args, **kwargs):
"""Draw filled contours on a labelled plot based on the given Cube.
With the basic call signature, contour "level" values are chosen
automatically::
contour(cube)
Supply a number to use *N* automatically chosen levels::
contour(cube, N)
Supply a sequence *V* to use explicitly defined levels::
contour(cube, V)
Keywords
--------
colorbar : bool, default=True
If True, an appropriate colorbar will be added to the plot.
See :func:`iris.plot.contourf` for details of valid keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
coords = kwargs.get("coords")
axes = kwargs.get("axes")
colorbar = kwargs.pop("colorbar", True)
result = iplt.contourf(cube, *args, **kwargs)
_label_with_points(cube, result, coords=coords, axes=axes, colorbar=colorbar)
return result
[docs]
def outline(cube, coords=None, color="k", linewidth=None, axes=None):
"""Draw cell outlines on a labelled plot based on the given Cube.
Parameters
----------
coords : list of :class:`~iris.coords.Coord` objects or coordinate names, optional
Use the given coordinates as the axes for the plot. The order of the
given coordinates indicates which axis to use for each, where the first
element is the horizontal axis of the plot and the second element is
the vertical axis of the plot.
color : str, default="k"
The color of the cell outlines. If None, the matplotlibrc setting
patch.edgecolor is used by default.
linewidth : number, optional
The width of the lines showing the cell outlines. If None, the default
width in patch.linewidth in matplotlibrc is used.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
result = iplt.outline(
cube, color=color, linewidth=linewidth, coords=coords, axes=axes
)
_label_with_bounds(cube, coords=coords, axes=axes)
return result
[docs]
def pcolor(cube, *args, **kwargs):
"""Draw a labelled pseudocolor plot based on the given Cube.
Keywords
--------
colorbar : bool, default=True
If True, an appropriate colorbar will be added to the plot.
See :func:`iris.plot.pcolor` for details of valid keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
coords = kwargs.get("coords")
axes = kwargs.get("axes")
colorbar = kwargs.pop("colorbar", True)
result = iplt.pcolor(cube, *args, **kwargs)
_label_with_bounds(cube, result, coords=coords, axes=axes, colorbar=colorbar)
return result
[docs]
def pcolormesh(cube, *args, **kwargs):
"""Draw a labelled pseudocolour plot based on the given Cube.
Keywords
--------
colorbar : bool, default=True
If True, an appropriate colorbar will be added to the plot.
See :func:`iris.plot.pcolormesh` for details of valid keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
coords = kwargs.get("coords")
axes = kwargs.get("axes")
colorbar = kwargs.pop("colorbar", True)
result = iplt.pcolormesh(cube, *args, **kwargs)
_label_with_bounds(cube, result, coords=coords, axes=axes, colorbar=colorbar)
return result
[docs]
def points(cube, *args, **kwargs):
"""Draw sample point positions on a labelled plot based on the given Cube.
See :func:`iris.plot.points` for details of valid keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
coords = kwargs.get("coords")
axes = kwargs.get("axes")
result = iplt.points(cube, *args, **kwargs)
_label_with_points(cube, coords=coords, axes=axes)
return result
[docs]
def plot(*args, **kwargs):
"""Draw a labelled line plot based on the given cube(s) or coordinate(s).
See :func:`iris.plot.plot` for details of valid arguments and
keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
axes = kwargs.get("axes")
result = iplt.plot(*args, **kwargs)
_label_1d_plot(*args, axes=axes)
return result
[docs]
def scatter(x, y, *args, **kwargs):
"""Draw a labelled scatter plot based on the given cubes or coordinates.
See :func:`iris.plot.scatter` for details of valid arguments and
keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
axes = kwargs.get("axes")
result = iplt.scatter(x, y, *args, **kwargs)
_label_1d_plot(x, y, axes=axes)
return result
[docs]
def fill_between(x, y1, y2, *args, **kwargs):
"""Draw a labelled fill_between plot based on the given cubes or coordinates.
See :func:`iris.plot.fill_between` for details of valid arguments and
keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
axes = kwargs.get("axes")
result = iplt.fill_between(x, y1, y2, *args, **kwargs)
_label_1d_plot(x, y1, axes=axes)
return result
[docs]
def hist(x, *args, **kwargs):
"""Compute and plot a labelled histogram.
See :func:`iris.plot.hist` for details of valid arguments and
keyword arguments.
Notes
-----
This function does not maintain laziness when called; it realises data.
See more at :doc:`/userguide/real_and_lazy_data`.
"""
axes = kwargs.get("axes")
result = iplt.hist(x, *args, **kwargs)
title = _title(x, with_units=False)
label = _title(x, with_units=True)
if axes is None:
axes = plt.gca()
orientation = kwargs.get("orientation")
if orientation == "horizontal":
axes.set_ylabel(label)
else:
axes.set_xlabel(label)
axes.set_title(title)
return result
# Provide a convenience show method from pyplot.
show = plt.show
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