[R] ignoring zeros or converting to NA

[Daniel Malter]

Sorry for jumping in. I haven't read the entire conversation. But imagine you
want to compute 1/x for the entire matrix and your matrix has 0s and NAs.
Then you could do:

##define function
f<-function(x){1/x}

##sample data 
y=c(0,1,2,3,4,5,6,7,NA) 

##arrange in matrix
mat=matrix(y,3,3) 

##apply function to matrix "mat"
##except 0s and NAs 
calc.mat=ifelse(mat==0|is.na(mat)==T,NA,f(mat))

##inspect resulting matrix
calc.mat

If you are concerned about near zeros instead of zeros, you could adjust the
ifelse condition. 

Best,
Daniel


rcoder wrote:
> 
> Hi everyone,
> 
> I have a matrix that has a combination of zeros and NAs. When I perform
> certain calculations on the matrix, the zeros generate "Inf" values. Is
> there a way to either convert the zeros in the matrix to NAs, or only
> perform the calculations if not zero (i.e. like using something similar to
> an !all(is.na() construct)?
> 
> Thanks,
> 
> rcoder
> 

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