[R] ignoring zeros or converting to NA
Roland Rau
roland.rproject at gmail.com
Wed Aug 13 17:23:20 CEST 2008
Hi,
since many suggestions are following the form of
x[x==0] (or similar)
I would like to ask if this is really recommended?
What I have learned (the hard way) is that one should not test for
equality of floating point numbers (which is the default for R's numeric
values, right?) since the binary representation of these (decimal)
floating point numbers is not necessarily exact (with the classic
example of decimal 0.1).
Is it okay in this case for the value zero where all binary elements are
zero? Or does R somehow recognize that it is an integer?
Just some questions out of curiosity.
Thank you,
Roland
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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