On Wed, 14 Dec 2011 13:41:12 -0600, "Pazzula, Dominic J " <[email protected]> wrote: > The subset index seems to drop (or is exclusive of) the last value. This can > be confusing if you are using range() to generate the array of indices. > Instead of needing the traditional range(start,end+1), you need to use > range(start,end+2) as the subset_dot() and the range() routine are exclusive > of the last value. > > Is this behavior as intended? > > import numpy as np > import pycuda as cuda > import pycuda.gpuarray > import pycuda.autoinit > > n = 3 > > a = np.array(range(0,n**2),ndmin=2) > a = a.astype(np.float32) > print a > g_a = cuda.gpuarray.to_gpu(a) > g_b = cuda.gpuarray.to_gpu(a) > > subset = cuda.gpuarray.to_gpu(np.array(range(2,5))) > > print "Subset Array", subset; > x = cuda.gpuarray.subset_dot(subset,g_a,g_b) > print "a[2:5] dot g[2:5]", x > > ------ > [[ 0. 1. 2. 3. 4. 5. 6. 7. 8.]] > Subset Array [2 3 4] > a[2:5] dot g[2:5] 13.0
The issue is that 'subset' ends up being an array of 64-bit integers, but the subset_* routines tacitly assume that you're giving them 32-bit integers. This is fixed in git, although for performance reasons I would still recommend 32-bit ints for 'subset', if you can get away with it. Andreas
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