Merge remote-tracking branch 'upstream/master' into docfix_06

doc/source/guide/plotting.rst

@@ -169,47 +169,89 @@ highlight a region of interest, and change the plot title.
     plt.colorbar()
     plt.show()
 
-By default :ref:`map` uses the `wcsaxes <http://wcsaxes.readthedocs.org/>`_
-package to improve the representation of world coordinates. In the
-examples above the axes were normal matplotlib axes.
-To create a custom `wcsaxes.WCSAxes` instance do the following ::
+
+Plotting Maps with wcsaxes
+--------------------------
+
+By default :ref:map checks if the `wcsaxes <http://wcsaxes.readthedocs.org/>`_ 
+package has been installed. If it is installed, 
+then `wcsaxes` is used to improve the representation of world coordinates,
+and calling ~sunpy.map.GenericMap.plot or~sunpy.map.GenericMap.peek() will use 
+wcsaxes for plotting. Unless a standard `matplotlib.axes.Axes` object is created.
+
+To explicitly create a `wcsaxes.WCSAxes` instance do the following ::
 
     >>> fig = plt.figure()   # doctest: +SKIP
     >>> ax = plt.subplot(projection=smap.wcs)   # doctest: +SKIP
 
-when overplotting data and using wcsaxes you have to use the transform keyword
-argument, also the native coordinate system of a `~wcsaxes.WCSAxes` is always
-in degrees ::
+when plotting on a `~wcsaxes.WCSAxes` axes, it will by default plot in pixel 
+coordinates, you can override this behavior and plot in 'world' coordinates
+by getting the transformation from the axes with ``ax.get_transform('world')``.
+Note: World coordinates are always in **degrees** so you will have to convert 
+to degrees.::
 
     >>> smap.plot()   # doctest: +SKIP
     >>> ax.plot((100*u.arcsec).to(u.deg), (500*u.arcsec).to(u.deg),
     ...         transform=ax.get_transform('world'))   # doctest: +SKIP
 
-Finally, here is a more complex example:
+Finally, here is a more complex example using SunPy maps, wcsaxes and Astropy 
+units to plot a AIA image and a zoomed in view of an active region.
 
 .. plot::
     :include-source:
 
+    import matplotlib.pyplot as plt
     from matplotlib import patches
     import astropy.units as u
 
     import sunpy.map
-    import matplotlib.pyplot as plt
     import sunpy.data.sample
 
+
+    # Define a region of interest
+    l = 250*u.arcsec
+    x0 = -100*u.arcsec
+    y0 = -400*u.arcsec
+
+    # Create a SunPy Map, and a second submap over the region of interest.
     smap = sunpy.map.Map(sunpy.data.sample.AIA_171_IMAGE)
-    submap = smap.submap([-100-250, -100+250]*u.arcsec, [-400-250, -400+250]*u.arcsec)
-    rect = patches.Rectangle([-100-250, -400-250], 500, 500, color = 'white', fill=False)
+    submap = smap.submap(u.Quantity([x0-l, x0+l]), u.Quantity([y0-l, y0+l]))
 
-    fig = plt.figure()
-    ax1 = fig.add_subplot(2,1,1)
+
+
+    # Create a new matplotlib figure, larger than default.
+    fig = plt.figure(figsize=(5,12))
+
+    # Add a first Axis, using the WCS from the map.
+    ax1 = fig.add_subplot(2,1,1, projection=smap.wcs)
+
+    # Plot the Map on the axes with default settings.
     smap.plot()
+
+    # Define a region to highlight with a box
+    # We have to convert the region of interest to degress, and then get the raw values.
+    bottom_left = u.Quantity([x0-l, y0-l]).to(u.deg).value
+    l2 = (l*2).to(u.deg).value
+
+    # create the rectangle, we use the world transformation to plot in physical units.
+    rect = patches.Rectangle(bottom_left, l2, l2, color='white', fill=False,
+                             transform=ax1.get_transform('world'))
+
+    # Add the rectangle to the plot.
     ax1.add_artist(rect)
 
-    ax2 = fig.add_subplot(2,1,2)
+
+
+    # Create a second axis on the plot.
+    ax2 = fig.add_subplot(2,1,2, projection=submap.wcs)
+
     submap.plot()
+
+    # Add a overlay grid.
     submap.draw_grid(grid_spacing=10*u.deg)
-    ax2.set_title('submap')
-    fig.subplots_adjust(hspace=0.4)
+
+    # Change the title.
+    ax2.set_title('Zoomed View')
+
 
     plt.show()

sunpy/map/mapcube.py

@@ -4,11 +4,11 @@
 
 import numpy as np
 import matplotlib.animation
-import matplotlib.pyplot as plt
 
 from sunpy.map import GenericMap
 
 from sunpy.visualization.mapcubeanimator import MapCubeAnimator
+from sunpy.visualization import wcsaxes_compat
 from sunpy.util import expand_list
 
 __all__ = ['MapCube']
@@ -161,7 +161,7 @@ def plot(self, axes=None, resample=None, annotate=True,
 
         """
         if not axes:
-            axes = plt.gca()
+            axes = wcsaxes_compat.gca_wcs(self.maps[0].wcs)
         fig = axes.get_figure()
 
         if not plot_function:
@@ -200,10 +200,18 @@ def annotate_frame(i):
         def updatefig(i, im, annotate, ani_data, removes):
             while removes:
                 removes.pop(0).remove()
+
             im.set_array(ani_data[i].data)
-            im.set_cmap(self.maps[i].cmap)
-            im.set_norm(self.maps[i].mpl_color_normalizer)
-            im.set_extent(np.concatenate((self.maps[i].xrange.value, self.maps[i].yrange.value)))
+            im.set_cmap(self.maps[i].plot_settings['cmap'])
+            im.set_norm(self.maps[i].plot_settings['norm'])
+
+            if wcsaxes_compat.is_wcsaxes(axes):
+                im.axes.reset_wcs(self.maps[i].wcs)
+                wcsaxes_compat.default_wcs_grid(axes)
+            else:
+                im.set_extent(np.concatenate((self.maps[i].xrange.value,
+                                              self.maps[i].yrange.value)))
+
             if annotate:
                 annotate_frame(i)
             removes += list(plot_function(fig, axes, self.maps[i]))

sunpy/visualization/mapcubeanimator.py

@@ -2,7 +2,8 @@
 
 __all__ = ['MapCubeAnimator']
 
-from sunpy.visualization import imageanimator
+from sunpy.visualization import imageanimator, wcsaxes_compat
+from sunpy.visualization.wcsaxes_compat import HAVE_WCSAXES, FORCE_NO_WCSAXES
 
 class MapCubeAnimator(imageanimator.BaseFuncAnimator):
     """
@@ -88,6 +89,10 @@ def updatefig(self, val, im, slider):
         im.set_array(self.data[i].data)
         im.set_cmap(self.mapcube[i].plot_settings['cmap'])
         im.set_norm(self.mapcube[i].plot_settings['norm'])
+        if wcsaxes_compat.is_wcsaxes(im.axes):
+            im.axes.reset_wcs(self.mapcube[i].wcs)
+            wcsaxes_compat.default_wcs_grid(im.axes)
+
         # Having this line in means the plot will resize for non-homogenous
         # maps. However it also means that if you zoom in on the plot bad
         # things happen.
@@ -121,6 +126,15 @@ def _annotate_plot(self, ind):
         self.axes.set_xlabel(xlabel)
         self.axes.set_ylabel(ylabel)
 
+    def _get_main_axes(self):
+        """
+        Create an axes which is wcsaxes if we have that...
+        """
+        if HAVE_WCSAXES and not FORCE_NO_WCSAXES:
+            return self.fig.add_subplot(111, projection=self.mapcube[0].wcs)
+        else:
+            return self.fig.add_subplot(111)
+
     def plot_start_image(self, ax):
         im = self.mapcube[0].plot(annotate=self.annotate, axes=ax,
                                        **self.imshow_kwargs)