Hi: If I remember correctly, I think I gave you something like mat[mat
== 0]<-NA. I think what you're doing below is pretty different from
that but I may not be understanding what you want ? Let me know if I can
clarify more because my intention was not to guide you
into doing below. Looping is generally not a good idea in R and often
unnecessary. If you send me whatever I sent you, maybe I can fix it up
for what
you want.
On Wed, Aug 13, 2008 at 4:39 PM, rcoder wrote:
Thank you for all your replies.
Borrowing an alternative solution kindly provided by Mark Leeds, I am
using
a conditional statement to pass non-zero values to a holding matrix
that has
cells initially set to NA. The code is as follows:
##Code Start
mat_zeroless<-matrix(NA,5000,2000) #generating holding matrix
for (j in 1:5000)
{
for (k in 1:2000)
{
if(mat[j,k]!=0) {mat_zeroless[j,k]<-mat[j,k]}
}
}
##Code End
Problems arise when the algorithm encounters NAs. Numbers are passed
to the
holding matrix, and zeros not, but when an NA is encountered, the
following
error is generated:
Error in if mat[j,k] !=0 { :missing value where TRUE/FALSE needed
I'm not sure how to resolve this.
Thanks,
rcoder
Henrik Bengtsson (max 7Mb) wrote:
FYI,
there is an isZero() in the R.utils package that allows you to
specify
the precision. It looks like this:
isZero <- function (x, neps=1, eps=.Machine$double.eps, ...) {
(abs(x) < neps*eps);
}
/Henrik
On Wed, Aug 13, 2008 at 8:23 AM, Roland Rau
<[EMAIL PROTECTED]>
wrote:
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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