How can I replace specific values within a large matrix with NA's in R

Question

My data is within a 96 X 12 numeric matrix. Sprinkled within the matrix are these -9999.0000 values that represent "no data". What's the most efficient way to replace these values with NA's?

Thanks

Answer 1

Try this:

m = matrix(sample(c(-9999.0,1:10), 10000, replace=T), ncol=100)

m[m==-9999.0] = NA

Answer 2

A similarly efficient way (at least with a few quick tests) is to use replace .

The syntax would be something like:

replace(m, m == -9999, NA)