On 01/03/2008, Charles R Harris <[EMAIL PROTECTED]> wrote: > > On Fri, Feb 29, 2008 at 10:53 AM, John Hunter <[EMAIL PROTECTED]> wrote: > > > I have a boolean array and would like to find the lowest index "ind" > > > where N contiguous elements are all True. Eg, if x is
[...] > Oops, ind = arange(len(x)). I suppose nonzero would work as well. I'm guessing you're alluding to the fact that diff(nonzero(x)) gives you a list of the run lengths of Falses in x (except possibly for the first one). If you have a fondness for the baroque, you can try numpy.where(numpy.convolve(x,[1,]*N,'valid')==N) For large N this can even use Fourier-domain convolution (though you'd then have to be careful about round-off error). Silly, really, it's O(NM) or O(N log M) instead of O(N). Anne _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
