[R] Counting zeros in a matrix

Leeds, Mark (IED) Mark.Leeds at morganstanley.com
Tue Nov 28 22:32:21 CET 2006


temp<-apply(A,1,sum(diff(x)) == -1 ) 


but check it because I haven't tested it and when things are not tested
there
can often be unforeseen problems. Also, may have to declare sum(diff(x))
== -1 as a separate function and then call it.
I'm not sure aobut that.






-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Guenther, Cameron
Sent: Tuesday, November 28, 2006 4:20 PM
To: r-help at stat.math.ethz.ch
Subject: [R] Counting zeros in a matrix

Hi All,

If you could help me with this problem I would greatly appreciate it.

Suppose I have a matrix A:

1 1 1 1 0 1 1 1 1
1 1 1 0 1 0 1 0 0
1 0 1 0 0 1 0 0 0
1 1 0 0 0 0 1 0 0

I would like, for each row, to sum the number of times a 0 appears in
front of a 1. So what I would like is to have
                   Sum
1 1 1 1 0 1 1 1 1   1
1 1 1 0 1 0 1 0 0   2 
1 0 1 0 0 1 0 0 0   2
1 1 0 0 0 0 1 0 0   1

I tried writing a function to do this but am getting mixed up in the
[i,j] coding.  This is just an example the real matrix is much larger.

Thanks in advance.



Cameron Guenther, Ph.D.
100 8th Ave. SE
St. Petersburg, Fl 33701
727-896-8626 ext. 4305
cameron.guenther at myfwc.com
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This is not an offer (or solicitation of an offer) to buy/se...{{dropped}}



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