On 2012/12/11 12:16 PM, Timothy Duly wrote: > Hi, > > I'm running into a problem with overlaying a scatter plot on a polygon > that is on a Basemap. The polygon covers up the scatter plot created by > the basemap. To show the issue, the simple example below and broken > down into three steps: 1) creating the map, 2) adding the red polygon, > and 3) adding the "x" markers via a scatter plot. You will see that the > "x" markers are not on top of the polygon. > > Why does the polygon cover up the markers, even though I have the > markers added after the polygon? Would there be a better way to do > this? I could set the polygon alpha to, say, 0.5, but this feature does > not show when I save it as an eps image. Therefore, I would like to > keep alpha=1.
Artists have a zorder attribute that controls the drawing order. Try adding the kwarg zorder=4 to your scatter call. I think that will take care of it. (Alternatively you could lower the zorder of the polygon.) Eric > > Thanks, > Tim > > from mpl_toolkits.basemap import Basemap > import numpy as np > from matplotlib.pyplot import * > from matplotlib.patches import Polygon > > > # --------------------- > # Part 1: Draw the map > # --------------------- > > # Hawaii: > lat_0 = 20.71-8. > lon_0 = 203.83 > > figure(1); clf(); > m = Basemap(width=2500e3,height=2500e3, > resolution='l',projection='stere', \ > lat_ts=lat_0,lat_0=lat_0,lon_0=lon_0) > > m.drawcoastlines() > m.fillcontinents(color='coral',lake_color='aqua') > > # draw parallels and meridians: > m.drawmapboundary(fill_color='aqua') > > lats = np.arange(np.floor(m.latmin),np.ceil(m.latmax),2.) > lons = np.arange(190.,211.,5.) > m.drawparallels(lats,labels=[True,False,False,False]) > m.drawmeridians(lons,labels=[False,False,False,True]) > > draw(); show() > > # --------------------- > # Part 2: Add a polygon > # --------------------- > > lon_poly = np.array([-160., -150., -150., -160.,]) > lat_poly = np.array([10., 10., 14., 14.,]) > X, Y = m(lon_poly, lat_poly) > xy = np.vstack([X,Y]).T > > poly = Polygon(xy, closed=True, \ > facecolor='red', \ > linewidth=1., \ > ) > > gca().add_patch(poly) > > # --------------------- > # Part 3: add some 'x' markers > # --------------------- > > lon_markers = np.arange(-168.,-144.,2.) > lat_markers = np.arange(5.,20.,1.) > X, Y = np.meshgrid(lon_markers, lat_markers) > > x, y = m(X.ravel(), Y.ravel()) > m.scatter(x,y,marker='x') > > draw(); show() > > > > ------------------------------------------------------------------------------ > LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial > Remotely access PCs and mobile devices and provide instant support > Improve your efficiency, and focus on delivering more value-add services > Discover what IT Professionals Know. Rescue delivers > http://p.sf.net/sfu/logmein_12329d2d > > > > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
