Files
geopandas/geopandas/plotting.py
T
Elliott Sales de Andrade 661e2da4e8 COMPAT: fix tests of Matplotlib 2.0.0 (#551)
* Fix default cmap for Matplotlib 2.0.0.

* TST: Fix determination of expected dash style.

In Matplotlib 2.0.0, there was a minimum dash length that was eventually
removed because it was problematic. The expected line style does not
apply this minimum.
2017-09-19 20:48:52 -07:00

522 lines
17 KiB
Python

from __future__ import print_function
from distutils.version import LooseVersion
import warnings
import numpy as np
def _flatten_multi_geoms(geoms, colors=None):
"""
Returns Series like geoms and colors, except that any Multi geometries
are split into their components and colors are repeated for all component
in the same Multi geometry. Maintains 1:1 matching of geometry to color.
Passing `color` is optional, and when no `color` is passed a list of None
values is returned as `component_colors`.
"Colors" are treated opaquely and so can actually contain any values.
Returns
-------
components : list of geometry
component_colors : list of whatever type `colors` contains
"""
if colors is None:
colors = [None] * len(geoms)
components, component_colors = [], []
# precondition, so zip can't short-circuit
assert len(geoms) == len(colors)
for geom, color in zip(geoms, colors):
if geom.type.startswith('Multi'):
for poly in geom:
components.append(poly)
# repeat same color for all components
component_colors.append(color)
else:
components.append(geom)
component_colors.append(color)
return components, component_colors
def plot_polygon_collection(ax, geoms, values=None, color=None,
cmap=None, vmin=None, vmax=None, **kwargs):
"""
Plots a collection of Polygon and MultiPolygon geometries to `ax`
Parameters
----------
ax : matplotlib.axes.Axes
where shapes will be plotted
geoms : a sequence of `N` Polygons and/or MultiPolygons (can be mixed)
values : a sequence of `N` values, optional
Values will be mapped to colors using vmin/vmax/cmap. They should
have 1:1 correspondence with the geometries (not their components).
Otherwise follows `color` / `facecolor` kwargs.
edgecolor : single color or sequence of `N` colors
Color for the edge of the polygons
facecolor : single color or sequence of `N` colors
Color to fill the polygons. Cannot be used together with `values`.
color : single color or sequence of `N` colors
Sets both `edgecolor` and `facecolor`
**kwargs
Additional keyword arguments passed to the collection
Returns
-------
collection : matplotlib.collections.Collection that was plotted
"""
from descartes.patch import PolygonPatch
from matplotlib.collections import PatchCollection
geoms, values = _flatten_multi_geoms(geoms, values)
if None in values:
values = None
# PatchCollection does not accept some kwargs.
if 'markersize' in kwargs:
del kwargs['markersize']
# color=None overwrites specified facecolor/edgecolor with default color
if color is not None:
kwargs['color'] = color
collection = PatchCollection([PolygonPatch(poly) for poly in geoms],
**kwargs)
if values is not None:
collection.set_array(np.asarray(values))
collection.set_cmap(cmap)
collection.set_clim(vmin, vmax)
ax.add_collection(collection, autolim=True)
ax.autoscale_view()
return collection
def plot_linestring_collection(ax, geoms, values=None, color=None,
cmap=None, vmin=None, vmax=None, **kwargs):
"""
Plots a collection of LineString and MultiLineString geometries to `ax`
Parameters
----------
ax : matplotlib.axes.Axes
where shapes will be plotted
geoms : a sequence of `N` LineStrings and/or MultiLineStrings (can be
mixed)
values : a sequence of `N` values, optional
Values will be mapped to colors using vmin/vmax/cmap. They should
have 1:1 correspondence with the geometries (not their components).
color : single color or sequence of `N` colors
Cannot be used together with `values`.
Returns
-------
collection : matplotlib.collections.Collection that was plotted
"""
from matplotlib.collections import LineCollection
geoms, values = _flatten_multi_geoms(geoms, values)
if None in values:
values = None
# LineCollection does not accept some kwargs.
if 'markersize' in kwargs:
del kwargs['markersize']
# color=None gives black instead of default color cycle
if color is not None:
kwargs['color'] = color
segments = [np.array(linestring)[:, :2] for linestring in geoms]
collection = LineCollection(segments, **kwargs)
if values is not None:
collection.set_array(np.asarray(values))
collection.set_cmap(cmap)
collection.set_clim(vmin, vmax)
ax.add_collection(collection, autolim=True)
ax.autoscale_view()
return collection
def plot_point_collection(ax, geoms, values=None, color=None,
cmap=None, vmin=None, vmax=None,
marker='o', markersize=None, **kwargs):
"""
Plots a collection of Point geometries to `ax`
Parameters
----------
ax : matplotlib.axes.Axes
where shapes will be plotted
geoms : sequence of `N` Points
values : a sequence of `N` values, optional
Values mapped to colors using vmin, vmax, and cmap.
Cannot be specified together with `color`.
markersize : scalar or array-like, optional
Size of the markers. Note that under the hood ``scatter`` is
used, so the specified value will be proportional to the
area of the marker (size in points^2).
Returns
-------
collection : matplotlib.collections.Collection that was plotted
"""
if values is not None and color is not None:
raise ValueError("Can only specify one of 'values' and 'color' kwargs")
x = geoms.x.values
y = geoms.y.values
# matplotlib 1.4 does not support c=None, and < 2.0 does not support s=None
if values is not None:
kwargs['c'] = values
if markersize is not None:
kwargs['s'] = markersize
collection = ax.scatter(x, y, color=color, vmin=vmin, vmax=vmax, cmap=cmap,
marker=marker, **kwargs)
return collection
def plot_series(s, cmap=None, color=None, ax=None, figsize=None, **style_kwds):
"""
Plot a GeoSeries.
Generate a plot of a GeoSeries geometry with matplotlib.
Parameters
----------
s : Series
The GeoSeries to be plotted. Currently Polygon,
MultiPolygon, LineString, MultiLineString and Point
geometries can be plotted.
cmap : str (default None)
The name of a colormap recognized by matplotlib. Any
colormap will work, but categorical colormaps are
generally recommended. Examples of useful discrete
colormaps include:
tab10, tab20, Accent, Dark2, Paired, Pastel1, Set1, Set2
color : str (default None)
If specified, all objects will be colored uniformly.
ax : matplotlib.pyplot.Artist (default None)
axes on which to draw the plot
figsize : pair of floats (default None)
Size of the resulting matplotlib.figure.Figure. If the argument
ax is given explicitly, figsize is ignored.
**style_kwds : dict
Color options to be passed on to the actual plot function, such
as ``edgecolor``, ``facecolor``, ``linewidth``, ``markersize``,
``alpha``.
Returns
-------
matplotlib axes instance
"""
if 'colormap' in style_kwds:
warnings.warn("'colormap' is deprecated, please use 'cmap' instead "
"(for consistency with matplotlib)", FutureWarning)
cmap = style_kwds.pop('colormap')
if 'axes' in style_kwds:
warnings.warn("'axes' is deprecated, please use 'ax' instead "
"(for consistency with pandas)", FutureWarning)
ax = style_kwds.pop('axes')
import matplotlib.pyplot as plt
if ax is None:
fig, ax = plt.subplots(figsize=figsize)
ax.set_aspect('equal')
# if cmap is specified, create range of colors based on cmap
values = None
if cmap is not None:
values = np.arange(len(s))
if hasattr(cmap, 'N'):
values = values % cmap.N
style_kwds['vmin'] = style_kwds.get('vmin', values.min())
style_kwds['vmax'] = style_kwds.get('vmax', values.max())
geom_types = s.geometry.type
poly_idx = np.asarray((geom_types == 'Polygon')
| (geom_types == 'MultiPolygon'))
line_idx = np.asarray((geom_types == 'LineString')
| (geom_types == 'MultiLineString'))
point_idx = np.asarray(geom_types == 'Point')
# plot all Polygons and all MultiPolygon components in the same collection
polys = s.geometry[poly_idx]
if not polys.empty:
# color overrides both face and edgecolor. As we want people to be
# able to use edgecolor as well, pass color to facecolor
facecolor = style_kwds.pop('facecolor', None)
if color is not None:
facecolor = color
values_ = values[poly_idx] if cmap else None
plot_polygon_collection(ax, polys, values_, facecolor=facecolor,
cmap=cmap, **style_kwds)
# plot all LineStrings and MultiLineString components in same collection
lines = s.geometry[line_idx]
if not lines.empty:
values_ = values[line_idx] if cmap else None
plot_linestring_collection(ax, lines, values_, color=color, cmap=cmap,
**style_kwds)
# plot all Points in the same collection
points = s.geometry[point_idx]
if not points.empty:
values_ = values[point_idx] if cmap else None
plot_point_collection(ax, points, values_, color=color, cmap=cmap,
**style_kwds)
plt.draw()
return ax
def plot_dataframe(df, column=None, cmap=None, color=None, ax=None,
categorical=False, legend=False, scheme=None, k=5,
vmin=None, vmax=None, figsize=None, **style_kwds):
"""
Plot a GeoDataFrame.
Generate a plot of a GeoDataFrame with matplotlib. If a
column is specified, the plot coloring will be based on values
in that column.
Parameters
----------
df : GeoDataFrame
The GeoDataFrame to be plotted. Currently Polygon,
MultiPolygon, LineString, MultiLineString and Point
geometries can be plotted.
column : str (default None)
The name of the column to be plotted. Ignored if `color` is also set.
cmap : str (default None)
The name of a colormap recognized by matplotlib.
categorical : bool (default False)
If False, cmap will reflect numerical values of the
column being plotted. For non-numerical columns, this
will be set to True.
color : str (default None)
If specified, all objects will be colored uniformly.
legend : bool (default False)
Plot a legend. Ignored if no `column` is given, or if `color` is given.
ax : matplotlib.pyplot.Artist (default None)
axes on which to draw the plot
scheme : str (default None)
Name of a choropleth classification scheme (requires PySAL).
A pysal.esda.mapclassify.Map_Classifier object will be used
under the hood. Supported schemes: 'Equal_interval', 'Quantiles',
'Fisher_Jenks'
k : int (default 5)
Number of classes (ignored if scheme is None)
vmin : None or float (default None)
Minimum value of cmap. If None, the minimum data value
in the column to be plotted is used.
vmax : None or float (default None)
Maximum value of cmap. If None, the maximum data value
in the column to be plotted is used.
figsize
Size of the resulting matplotlib.figure.Figure. If the argument
axes is given explicitly, figsize is ignored.
**style_kwds : dict
Color options to be passed on to the actual plot function, such
as ``edgecolor``, ``facecolor``, ``linewidth``, ``markersize``,
``alpha``.
Returns
-------
matplotlib axes instance
"""
if 'colormap' in style_kwds:
warnings.warn("'colormap' is deprecated, please use 'cmap' instead "
"(for consistency with matplotlib)", FutureWarning)
cmap = style_kwds.pop('colormap')
if 'axes' in style_kwds:
warnings.warn("'axes' is deprecated, please use 'ax' instead "
"(for consistency with pandas)", FutureWarning)
ax = style_kwds.pop('axes')
if column and color:
warnings.warn("Only specify one of 'column' or 'color'. Using "
"'color'.", UserWarning)
column = None
import matplotlib
import matplotlib.pyplot as plt
if column is None:
return plot_series(df.geometry, cmap=cmap, color=color, ax=ax,
figsize=figsize, **style_kwds)
if df[column].dtype is np.dtype('O'):
categorical = True
# Define `values` as a Series
if categorical:
if cmap is None:
if LooseVersion(matplotlib.__version__) >= '2.0.1':
cmap = 'tab10'
elif LooseVersion(matplotlib.__version__) >= '2.0.0':
# Erroneous name.
cmap = 'Vega10'
else:
cmap = 'Set1'
categories = list(set(df[column].values))
categories.sort()
valuemap = dict([(k, v) for (v, k) in enumerate(categories)])
values = np.array([valuemap[k] for k in df[column]])
else:
values = df[column]
if scheme is not None:
binning = __pysal_choro(values, scheme, k=k)
# set categorical to True for creating the legend
categorical = True
binedges = [values.min()] + binning.bins.tolist()
categories = ['{0:.2f} - {1:.2f}'.format(binedges[i], binedges[i+1])
for i in range(len(binedges)-1)]
values = np.array(binning.yb)
if ax is None:
fig, ax = plt.subplots(figsize=figsize)
ax.set_aspect('equal')
mn = values.min() if vmin is None else vmin
mx = values.max() if vmax is None else vmax
geom_types = df.geometry.type
poly_idx = np.asarray((geom_types == 'Polygon')
| (geom_types == 'MultiPolygon'))
line_idx = np.asarray((geom_types == 'LineString')
| (geom_types == 'MultiLineString'))
point_idx = np.asarray(geom_types == 'Point')
# plot all Polygons and all MultiPolygon components in the same collection
polys = df.geometry[poly_idx]
if not polys.empty:
plot_polygon_collection(ax, polys, values[poly_idx],
vmin=mn, vmax=mx, cmap=cmap, **style_kwds)
# plot all LineStrings and MultiLineString components in same collection
lines = df.geometry[line_idx]
if not lines.empty:
plot_linestring_collection(ax, lines, values[line_idx],
vmin=mn, vmax=mx, cmap=cmap, **style_kwds)
# plot all Points in the same collection
points = df.geometry[point_idx]
if not points.empty:
plot_point_collection(ax, points, values[point_idx],
vmin=mn, vmax=mx, cmap=cmap, **style_kwds)
if legend and not color:
from matplotlib.lines import Line2D
from matplotlib.colors import Normalize
from matplotlib import cm
norm = Normalize(vmin=mn, vmax=mx)
n_cmap = cm.ScalarMappable(norm=norm, cmap=cmap)
if categorical:
patches = []
for value, cat in enumerate(categories):
patches.append(
Line2D([0], [0], linestyle="none", marker="o",
alpha=style_kwds.get('alpha', 1), markersize=10,
markerfacecolor=n_cmap.to_rgba(value)))
ax.legend(patches, categories, numpoints=1, loc='best')
else:
n_cmap.set_array([])
ax.get_figure().colorbar(n_cmap, ax=ax)
plt.draw()
return ax
def __pysal_choro(values, scheme, k=5):
"""
Wrapper for choropleth schemes from PySAL for use with plot_dataframe
Parameters
----------
values
Series to be plotted
scheme
pysal.esda.mapclassify classificatin scheme
['Equal_interval'|'Quantiles'|'Fisher_Jenks']
k
number of classes (2 <= k <=9)
Returns
-------
binning
Binning objects that holds the Series with values replaced with
class identifier and the bins.
"""
try:
from pysal.esda.mapclassify import (
Quantiles, Equal_Interval, Fisher_Jenks)
schemes = {}
schemes['equal_interval'] = Equal_Interval
schemes['quantiles'] = Quantiles
schemes['fisher_jenks'] = Fisher_Jenks
scheme = scheme.lower()
if scheme not in schemes:
raise ValueError("Invalid scheme. Scheme must be in the"
" set: %r" % schemes.keys())
binning = schemes[scheme](values, k)
return binning
except ImportError:
raise ImportError("PySAL is required to use the 'scheme' keyword")