Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: Peter Otten <__peter__@web.de>
Newsgroups: comp.lang.python
Subject: Re: SUM only of positive numbers from array
Date: Fri, 08 Jan 2016 09:17:42 +0100
Organization: None
Lines: 27
Message-ID: <mailman.59.1452241084.2305.python-list@python.org>
References: <50beb098-f854-4b17-b157-1be075d91f4d@googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7Bit
X-Trace: news.uni-berlin.de F8haxBumQP1ugb/h1W96UwD227ZMbfJ5qvptj7+iW+YQ==
Return-Path: <python-python-list@m.gmane.org>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.000
X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'true,': 0.04; 'false,': 0.07; 'problem?': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'count,': 0.16; 'help...': 0.16; 'numpy': 0.16; 'received:80.91.229.3': 0.16; 'received:dip0.t-ipconnect.de': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'received:t-ipconnect.de': 0.16; 'subject:array': 0.16; 'wrote:': 0.16; '>>>': 0.20; 'all,': 0.20; 'import': 0.24; 'header:User- Agent:1': 0.26; 'header:X-Complaints-To:1': 0.26; 'subject:numbers': 0.29; 'code': 0.30; 'should': 0.36; 'to:addr :python-list': 0.36; 'subject:: ': 0.37; 'received:org': 0.37; 'subject:from': 0.39; 'to:addr:python.org': 0.40; 'received:de': 0.40; 'skip:n 10': 0.62; 'sum': 0.69; 'sum.': 0.84
X-Injected-Via-Gmane: http://gmane.org/
X-Gmane-NNTP-Posting-Host: p57bd972e.dip0.t-ipconnect.de
User-Agent: KNode/4.13.3
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.20+
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Xref: csiph.com comp.lang.python:101363

Davorin Bajic wrote:

> Hi All,
> 
> I should help...
> 
> I want to calculate the sum of a positive number, for each row:
> 
> 
> x = ((mat_1 / s_1T)-(s_2 / total))
> y = (np.sum(x > 0, axis=1)).reshape(-1, 1).tolist()
> 
> However, this part of the code only calculation count, I need sum.
> 
> Any ideas how to solve this problem?

Use x>0 as "index":

>>> import numpy
>>> x = numpy.array([1, -2, 3])
>>> x>0
array([ True, False,  True], dtype=bool)
>>> x[x>0]
array([1, 3])
>>> x[x>0].sum()
4