The application is essentially filtering 1D arrays, typically N is

20e6, the required result is y[1:N].

Gerry -----Original Message----- From: numpy-discussion-bounces@scipy.org [mailto:numpy-discussion-bounces@scipy.org] On Behalf Of Alan G Isaac Sent: Wednesday, May 06, 2009 10:25 AM To: Discussion of Numerical Python Subject: Re: [Numpy-discussion] Recurrence relationships On 5/6/2009 10:00 AM Talbot, Gerry apparently wrote:

for n in xrange(1,N): y[n] = A*x[n] + B*y[n-1]

So, x is known before you start? How big is N? Also, is y.shape (N,)? Do you need all of y or only y[N]? Alan Isaac _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion