New example: contours without making an HDU

contours_without_a_file/contour_example.py

@@ -0,0 +1,44 @@
+import aplpy
+import numpy as np
+from matplotlib import pyplot as plt
+
+# Load up stars
+ra,dec = np.loadtxt('../data/sources.txt').T
+grid,yedges,xedges = np.histogram2d(ra,dec,bins=(np.linspace(265.83,266.97,100),np.linspace(-29.43,-28.43,100)))
+xcenters = (xedges[1:] + xedges[:-1])/2.
+ycenters = (yedges[1:] + yedges[:-1])/2.
+Xgrid, Ygrid = np.meshgrid(ycenters, xcenters)
+extent = [xedges[0], xedges[-1], yedges[0], yedges[-1]]
+
+CS = plt.contour(Xgrid, Ygrid, grid, extent=extent, levels=np.logspace(0,2,11))
+
+
+def get_contour_verts(cn):
+    contours = []
+    # for each contour line
+    for cc in cn.collections:
+        paths = []
+        # for each separate section of the contour line
+        for pp in cc.get_paths():
+            xy = []
+            # for each segment of that section
+            for vv in pp.iter_segments():
+                xy.append(vv[0])
+            paths.append(np.vstack(xy))
+        contours.append(paths)
+
+    return contours
+
+contours = get_contour_verts(CS)
+
+
+F = aplpy.FITSFigure('../data/2MASS_k.fits.gz')
+F.show_grayscale()
+
+for ii,contours_at_level in enumerate(contours):
+    clines = [cl.T for cl in contours_at_level]
+    F.show_lines(clines,zorder=10,layer='contour_level_%i' % ii,color='r')
+
+F.refresh()
+
+F.save('external_contour_example.png')