July 6, 2010
7:25 p.m.
On 7/6/10 10:42 , numpy-discussion-request@scipy.org wrote:
Date: Tue, 06 Jul 2010 10:02:57 -0400 From: Alan G Isaac<aisaac@american.edu> Subject: Re: [Numpy-discussion] reverse cumsum? To: Discussion of Numerical Python<numpy-discussion@scipy.org> Message-ID:<4C333791.5010505@american.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 7/6/2010 9:56 AM, Ken Basye wrote:
Is there a simple way to get a cumsum in reverse order?
> x = np.arange(10) > x[::-1].cumsum()[::-1] array([45, 45, 44, 42, 39, 35, 30, 24, 17, 9])
Is that what you want?
Alan Isaac
Or, you can do: In [1]: a = np.arange(10) In [5]: np.sum(a) - np.cumsum(a) Out[5]: array([45, 44, 42, 39, 35, 30, 24, 17, 9, 0]) Jonathan