Code bug unresolved involving if condition

Thanks a lot
I had corrected that already after thinking for a while about the cause of
the bug

However I still have some trouble in trying to set the Matrix[i,j+1] term
to Missingness.

I am not sure how to use the generic function `is.na<-' which sets elements
to `NA'.

      {if (is.na(Matrix[i,j])) (is.na(Matrix[i,j+1])<-1)}

does not work to set my  Matrix[i,j+1]  term to NA

Thanks in advance for any help




|---------+---------------------------->
|         |           ripley at stats.ox.a|
|         |           c.uk             |
|         |                            |
|         |           04/25/03 05:34 PM|
|         |                            |
|---------+---------------------------->
  >------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                              |
  |       To:       Vincent STOLIAROFF/fr/socgen at socgen                                                                          |
  |       cc:       r-help at stat.math.ethz.ch                                                                                     |
  |       Subject:  Re: [R] Code bug unresolved involving if condition                                                           |
  >------------------------------------------------------------------------------------------------------------------------------|



The message is both pleasant and accurate!  It indicates that you have
made an error, and tells you what the error is.

foo == NA is always missing, since NA denotes a missing value.
Use is.na(foo): see ?is.na.

Hi R lovers!

I am a beginner in coding with R so my question may be very easily solved
but I don't know how.

I have written the following function in a .txt file


ClearDelta <- function(Matrix)
{
ncol<-ncol(Matrix);nrow<-nrow(Matrix);
for (i in 1:nrow) {
                  for (j in 1:(ncol-1))
                        {if (Matrix[i,j]==NA) (NA->Matrix[i,j+1])}
                  }
}

I can charge it with the source() command
But I get the following message when applied to a matrix

ClearDelta(MatCor)

Error in if (Matrix[i, j] == NA) (Matrix[i, j + 1] <- NA) :
        missing value where logical needed

MatCor is the following Matrix

MatCor

           [,1]         [,2]       [,3]
[1,]         NA          0.9870676  0.04648933
[2,] 0.98706757  1.0000000 -0.17353590
[3,] 0.04648933 -0.1735359  1.00000000

Do you know why I get such an unpleasant message from so polite a software?

Thanks to anybody who could help.

--
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595







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