Message-ID: <49D8CEA3.9030909@erasmusmc.nl>
Date: 2009-04-05T15:30:43Z
From: Dimitris Rizopoulos
Subject: number of zeros in a matrix -row by row
In-Reply-To: <22893147.post@talk.nabble.com>
if 'M' is your matrix, then try this:
rowSums(M == 0)
I hope it helps.
Best,
Dimitris
onyourmark wrote:
> Hi. I have an n x m matrix M some of who's entries are zeros. I want to know
> how many zeros there are in each row -perhaps stored in a 1 x n vector
> which lists the number of zeros for each row of M.
>
> Before I had a vector V and I was able to get the number of zeros in V by
> doing length(V[ V==0]) but when I try something similar for M, like M[ M==0]
> it creates a vector not a matrix and so this does not work. Does anyone have
> a solution to this?
>
> Thank you.
--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center
Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014