Merge pull request #43 from darribas/add#25

Adding attribution text

Author: darribas

contextily/__init__.py

@@ -5,6 +5,6 @@
 from . import tile_providers as sources
 from .place import Place, plot_map
 from .tile import *
-from .plotting import add_basemap
+from .plotting import add_basemap, add_attribution
 
 __version__ = '0.99.0.dev'

contextily/place.py

@@ -4,7 +4,7 @@
 import matplotlib.pyplot as plt
 from warnings import warn
 from .tile import howmany, bounds2raster, bounds2img, _sm2ll, _calculate_zoom
-from .plotting import ATTRIBUTION, INTERPOLATION, ZOOM
+from .plotting import ATTRIBUTION, INTERPOLATION, ZOOM, add_attribution
 
 class Place(object):
     """Geocode a place by name and get its map.
@@ -104,7 +104,7 @@ def _get_map(self):
         return im, bbox
 
     def plot(self, ax=None, zoom=ZOOM, interpolation=INTERPOLATION, 
-             attribution_text = ATTRIBUTION):
+             attribution = ATTRIBUTION):
         """
         Plot a `Place` object
         ...
@@ -124,8 +124,8 @@ def plot(self, ax=None, zoom=ZOOM, interpolation=INTERPOLATION,
                               [Optional. Default='bilinear'] Interpolation
                               algorithm to be passed to `imshow`. See
                               `matplotlib.pyplot.imshow` for further details.
-        attribution_text    : str
-                              [Optional. Default=''] Text to be added at the
+        attribution         : str
+                              [Optional. Defaults to standard `ATTRIBUTION`] Text to be added at the
                               bottom of the axis.
 
         Returns
@@ -152,6 +152,8 @@ def plot(self, ax=None, zoom=ZOOM, interpolation=INTERPOLATION,
             axisoff = True
         ax.imshow(im, extent=bbox, interpolation=interpolation)
         ax.set(xlabel="X", ylabel="Y")
+        if attribution:
+            add_attribution(ax, attribution)
         if title is not None:
             ax.set(title=title)
         if axisoff:
@@ -163,7 +165,8 @@ def __repr__(self):
             self.place, self.n_tiles, self.zoom, self.im.shape[:2])
         return s
 
-def plot_map(place, bbox=None, title=None, ax=None, axis_off=True, latlon=True):
+def plot_map(place, bbox=None, title=None, ax=None, axis_off=True,
+        latlon=True, attribution = ATTRIBUTION):
     """Plot a map of the given place.
 
     Parameters
@@ -176,6 +179,9 @@ def plot_map(place, bbox=None, title=None, ax=None, axis_off=True, latlon=True):
         The axis on which to plot. If None, one will be created.
     axis_off : bool
         Whether to turn off the axis border and ticks before plotting.
+    attribution : str
+                  [Optional. Default to standard `ATTRIBUTION`] Text to be added at the
+                  bottom of the axis.
 
     Returns
     -------
@@ -208,7 +214,8 @@ def plot_map(place, bbox=None, title=None, ax=None, axis_off=True, latlon=True):
     ax.set(xlabel="X", ylabel="Y")
     if title is not None:
         ax.set(title=title)
-
+    if attribution:
+        add_attribution(ax, attribution)
     if axis_off is True:
         ax.set_axis_off()
     return ax

contextily/plotting.py

@@ -3,13 +3,15 @@
 import numpy as np
 from . import tile_providers as sources
 from .tile import _calculate_zoom, bounds2img, _sm2ll
+from matplotlib import patheffects
 
-ATTRIBUTION = ''
 INTERPOLATION = 'bilinear'
 ZOOM = 'auto'
+ATTRIBUTION = ("Map tiles by Stamen Design, under CC BY 3.0. "\
+               "Data by OpenStreetMap, under ODbL.")
 
 def add_basemap(ax, zoom=ZOOM, url=sources.ST_TERRAIN, 
-		interpolation=INTERPOLATION, attribution_text = ATTRIBUTION, 
+		interpolation=INTERPOLATION, attribution = ATTRIBUTION, 
                 **extra_imshow_args):
     """
     Add a (web/local) basemap to `ax`
@@ -33,8 +35,8 @@ def add_basemap(ax, zoom=ZOOM, url=sources.ST_TERRAIN,
                           [Optional. Default='bilinear'] Interpolation
                           algorithm to be passed to `imshow`. See
                           `matplotlib.pyplot.imshow` for further details.
-    attribution_text    : str
-                          [Optional. Default=''] Text to be added at the
+    attribution         : str
+                          [Optional. Defaults to standard `ATTRIBUTION`] Text to be added at the
                           bottom of the axis.
     **extra_imshow_args : dict
                           Other parameters to be passed to `imshow`.
@@ -90,5 +92,35 @@ def add_basemap(ax, zoom=ZOOM, url=sources.ST_TERRAIN,
     # Plotting
     ax.imshow(image, extent=extent, 
               interpolation=interpolation, **extra_imshow_args)
+    if attribution:
+        add_attribution(ax, attribution)
     return ax
 
+def add_attribution(ax, att=ATTRIBUTION):
+    '''
+    Utility to add attribution text
+    ...
+
+    Arguments
+    ---------
+    ax                  : AxesSubplot
+                          Matplotlib axis with `x_lim` and `y_lim` set in Web
+                          Mercator (EPSG=3857)
+    att                 : str
+                          [Optional. Defaults to standard `ATTRIBUTION`] Text to be added at the
+                          bottom of the axis.
+
+    Returns
+    -------
+    ax                  : AxesSubplot
+                          Matplotlib axis with `x_lim` and `y_lim` set in Web
+                          Mercator (EPSG=3857) and attribution text added
+    '''
+    minX, maxX = ax.get_xlim()
+    minY, maxY = ax.get_ylim()
+    ax.text(minX + (maxX - minX) * 0.005, 
+            minY + (maxY - minY) * 0.005, 
+            att, size=8, 
+            path_effects=[patheffects.withStroke(linewidth=2,
+                                                 foreground="w")])
+    return ax

tests/test_ctx.py

@@ -193,3 +193,7 @@ def test_add_basemap():
     assert_array_almost_equal(ax.images[0].get_array().mean(),
                               184.10237852536648)
 
+def test_attribution():
+    f, ax = matplotlib.pyplot.subplots(1)
+    ax = ctx.add_attribution(ax, 'Test')
+