On Sunday, June 19, 2011, Lukmanul Hakim <plgse...@yahoo.com> wrote: > Hello, > > I would like to ask for some hints > and help. I am currently trying to plot a "pseudo contour" over a Basemap. > This contour is confined by borders obtained from a shapefile. I can generate > the contour, I can retrieve the shapefile and put them on a basemap. What I > have not been able to do is to limit the contour plot such that it only fills > the area defined by a shapefile (in my case it is bordered by Province > Lampung). You can use different shapefile for example, as the point of my > question is how to limit contour fill by a shapefile. > > Shapefile can be downloaded from http://www.gadm.org/data/shp/IDN_adm.zip > > The generated figure can be found here: > https://lh3.googleusercontent.com/-hMlwe6MAjdc/Tf6HlxYxn1I/AAAAAAAAAEY/exdzSv30ZL4/s640/to_matplotlib_userlists.png > > Thanks for the help! > -- > Lukmanul Hakim > > Here's the code: > ---------------- > from pylab import cm > import matplotlib.pyplot as plt > import numpy as np > from mpl_toolkits.basemap import Basemap > > #Define area about Province Lampung > ulat, llat, ulon, llon = -2.5, -6.5, 107, 103 > m = Basemap(projection='merc', lon_0=0.0, llcrnrlon=llon, > llcrnrlat=llat, urcrnrlon=ulon, urcrnrlat=ulat, > resolution='i') > > > #Read shapefile of Province Lampung > s = m.readshapefile('E:/Works/UNILA/Research/IDN_adm/LampungMap/LampungMap', > 'lampung') > > #Define area for contour plot > llon1,ulon1 = 103,106 > llat1,ulat1 = -6,-3.5 > > #Generate random data > nx,ny=5,5 > data2 = np.random.sample((ny,nx)) > x = np.linspace(llon1, ulon1, nx) > y = np.linspace(llat1, ulat1, ny) > X,Y = np.meshgrid(x,y) > px,py = m(X,Y) > m.contourf(px, py, data2, cmap=cm.jet) > m.drawcoastlines()#(linewidth=0.5) > m.drawparallels(np.arange(-6.5,-2.5,1.),labels=[1,0,0,0],color='black',dashes=[1,0],labelstyle='+/-',linewidth=0.2) > # draw parallels > m.drawmeridians(np.arange(102.,108.,1.),labels=[0,0,0,1],color='black',dashes=[1,0],labelstyle='+/-',linewidth=0.2) > # draw meridians > > plt.show()
Not exactly sure how to do this, but if you can get a true/false mask of the region in the same shape as the input data, then you can have a masked array that goes into contourf. Any area where the mask was true will be blanked. The hard part, though is getting the mask. I hope that helps! Ben Root ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
