Jeff Whitaker wrote: > Armin Moser wrote: >> Hi, >> >> I would like to interpolate an array of shape (801,676) to regularily >> spaced datapoints using griddata. This interpolation is quick if the >> (x,y) supporting points are computed as X,Y = meshgrid(x,y). If this >> condition is not fullfilled the delaunay triangulation is extremely >> slow, i.e. not useable. Is this a known property of the used >> triangulation? The triangulation can be performed with matlab without >> any problems. >> >> Armin >> > > Armin: You could try installing the natgrid toolkit and see if that > speeds up griddata at all. If not, please post a test script with data > and maybe we can figure out what is going on. I have already tried natgrid and it didn't improve the situation. As suggested I append a script demonstrating the problem.
Thanks Armin ------8<------------- from numpy import * from pylab import * import time deg2rad = pi/180.0 ai = 0.12*deg2rad x = linspace(13,40,676) y = linspace(10,22,801) x = x*deg2rad y = y*deg2rad [x,y] = meshgrid(x,y) z = (x**2+y**2) xi = linspace(x.min(),x.max(),x.shape[1]) yi = linspace(y.min(),y.max(),y.shape[0]) tic= time.time() zi = griddata(x.flatten(),y.flatten(),z.flatten(),xi,yi) toc = time.time() print toc-tic fac = 2*pi/1.2681 nx = fac * (cos(y)*cos(x) - cos(ai)) ny = fac * (cos(y)*sin(x)) nz = fac * (sin(y) + sin(ai)) np = sqrt(nx**2 + ny**2) z = (np**2+nz**2)*exp(-0.001*nz) xi = linspace(np.min(),np.max(),x.shape[1]) yi = linspace(nz.min(),nz.max(),y.shape[0]) tic = time.time() zi = griddata(np.flatten(),nz.flatten(),z.flatten(),xi,yi) toc = time.time() print toc-tic ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
