number of zeros in a matrix -row by row

Dear Dimitris,

Thanks very much. I tried dim(M) and get:
[1] 5030 2142

which I thought meant that my matrix M is actually a matrix, but
I tried  str(M) and get:

 int [1:5030, 1:2142] 2 1 2 0 1 0 2 1 2 -1 ...

When I tried 
rowSums(M == 0)

I got:
Error in rowSums[M == 0] : 
  object of type 'closure' is not subsettable


What am I doing wrong?

Thanks so much.



Dimitris Rizopoulos-4 wrote:

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
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