[R] How to sum only a few elements in a line

[Peter Alspach]

Tena koe Marcio

Try something like (untested)

apply(yourMatrix, 1, function(x) sum(x[x!=9])) 

HTH ...

Peter Alspach

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of Marcio Resende
> Sent: Thursday, 26 November 2009 9:27 a.m.
> To: r-help at r-project.org
> Subject: [R] How to sum only a few elements in a line
> 
> 
> Hello,
> 
> I have a matrix with the numbers 0,1 and 9 I would like to 
> write a function that could sum each line skiping everytime a 
> number 9 appears for example [0 1 0 1 1 9 1] the sum would be 4.
> However I cannot replace 9 by 0 otherwise after the sum is 
> done I wouldn´t be able to distiguish which ones were real 
> zeros and which ones were nines replaced by zero just to sum.
> Thank you very much
> 
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