Re: [R] missing TRUE/FALSE error in conditional construct
The problem is that if x is either NA or NaN then x != 0 is NA (and not FALSE
or TRUE) and the function is.nan tests for a NaN but not for NA, i.e.
is.nan(NA) returns FALSE.
You can do something like:
mat_zeroless[!is.na(mat) & mat != 0] <- mat[!is.na(mat) & mat != 0]
--- On Thu, 14/8/08, rcoder <[EMAIL PROTECTED]> wrote:
> From: rcoder <[EMAIL PROTECTED]>
> Subject: [R] missing TRUE/FALSE error in conditional construct
> To: r-help@r-project.org
> Received: Thursday, 14 August, 2008, 8:16 AM
> Hi everyone,
>
> I posted something similar to this in reply to another
> post, but there seems
> to be a problem getting it onto the board, so I'm
> starting a new post.
>
> I am trying to use conditional formatting to select
> non-zero and non-NaN
> values from a matrix and pass them into another matrix. The
> problem is that
> I keep encountering an error message indicating the
> ":missing value where
> TRUE/FALSE needed "
>
> My code is as follows:
>
> ##Code Start
> mat_zeroless<-matrix(NA,5000,2000) #generating holding
> matrix
>
> ##Assume source matrix containing combination of values,
> NaNs and zeros##
> for (j in 1:5000)
> {
> for (k in 1:2000)
> {
> if(mat[j,k]!=0 & !is.NaN(mat[j,k]))
> {mat_zeroless[j,k]<-mat[j,k]}
> }
> }
> ##Code End
>
> Error in if (mat[j,k] !=0 & !is.NaN(mat[j,k])) {
> :missing value where
> TRUE/FALSE needed
>
> I'm not sure how to resolve this.
>
> rcoder
> --
> View this message in context:
> http://www.nabble.com/missing-TRUE-FALSE-error-in-conditional-construct-tp18972244p18972244.html
> Sent from the R help mailing list archive at Nabble.com.
>
> __
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained,
> reproducible code.
__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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Re: [R] missing TRUE/FALSE error in conditional construct
> -Original Message-
> From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]
> On Behalf Of rcoder
> Sent: Wednesday, August 13, 2008 3:17 PM
> To: r-help@r-project.org
> Subject: [R] missing TRUE/FALSE error in conditional construct
>
>
> Hi everyone,
>
> I posted something similar to this in reply to another post, but there
> seems
> to be a problem getting it onto the board, so I'm starting a new post.
>
> I am trying to use conditional formatting to select non-zero and
non-NaN
> values from a matrix and pass them into another matrix. The problem is
> that
> I keep encountering an error message indicating the ":missing value
where
> TRUE/FALSE needed "
>
> My code is as follows:
>
> ##Code Start
> mat_zeroless<-matrix(NA,5000,2000) #generating holding matrix
>
> ##Assume source matrix containing combination of values, NaNs and
zeros##
> for (j in 1:5000)
> {
> for (k in 1:2000)
> {
> if(mat[j,k]!=0 & !is.NaN(mat[j,k])) {mat_zeroless[j,k]<-mat[j,k]}
> }
> }
> ##Code End
>
> Error in if (mat[j,k] !=0 & !is.NaN(mat[j,k])) { :missing value where
> TRUE/FALSE needed
>
> I'm not sure how to resolve this.
This seems to do what you appear to need,
no loops required (always best whenever possible):
> set.seed(123)
> mat <- matrix(sample(1:10), nrow = 5)
> mat
[,1] [,2]
[1,]31
[2,]8 10
[3,]49
[4,]72
[5,]65
> is.na(mat) <- c(2, 3)
> mat
[,1] [,2]
[1,]31
[2,] NA 10
[3,] NA9
[4,]72
[5,]65
> mat[5,] <- 0
> mat
[,1] [,2]
[1,]31
[2,] NA 10
[3,] NA9
[4,]72
[5,]00
> matno0 <- matrix(NA, nrow = nrow(mat), ncol = ncol(mat))
> matno0
[,1] [,2]
[1,] NA NA
[2,] NA NA
[3,] NA NA
[4,] NA NA
[5,] NA NA
> mat[!is.na(mat) & !(mat == 0)]
[1] 3 7 1 10 9 2
> matno0[!is.na(mat) & !(mat == 0)] <- mat[!is.na(mat) & !(mat == 0)]
> matno0
[,1] [,2]
[1,]31
[2,] NA 10
[3,] NA9
[4,]72
[5,] NA NA
>
Other issues:
The error messages you are seeing generally
are happening because you are generating
non-scalar TRUE / FALSE outcomes or
NA outcomes in your if() clause.
An if() clause should generate scalar
TRUE or FALSE only.
To this end, the S language provides
the operators '&&' (scalar AND)
and '||' (scalar OR) for use in
logical scalar clauses. Further,
if the first argument to '&&' tests
FALSE, the second is not even evaluated,
so you could have done
if ( !is.na(mat[j, k]) && mat[j, k] != 0 ) { blah }
In this case, once the NA is found, the if() clause
evaluation is over and you don't have to worry about
the NA that will result from the second argument
mat[j, k] != 0
> matno0 <- matrix(NA, nrow = nrow(mat), ncol = ncol(mat))
> matno0
[,1] [,2]
[1,] NA NA
[2,] NA NA
[3,] NA NA
[4,] NA NA
[5,] NA NA
> for ( j in 1:5 ) {
+ for ( k in 1:2 ) {
+ if ( !is.na(mat[j, k]) && mat[j, k] != 0 ) { matno0[j, k] <- mat[j,
k] }
+ }
+ }
>
> matno0
[,1] [,2]
[1,]31
[2,] NA 10
[3,] NA9
[4,]72
[5,] NA NA
>
HTH
Steve McKinney
>
> rcoder
> --
> View this message in context:
http://www.nabble.com/missing-TRUE-FALSE-
> error-in-conditional-construct-tp18972244p18972244.html
> Sent from the R help mailing list archive at Nabble.com.
>
> __
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[R] missing TRUE/FALSE error in conditional construct
Hi everyone,
I posted something similar to this in reply to another post, but there seems
to be a problem getting it onto the board, so I'm starting a new post.
I am trying to use conditional formatting to select non-zero and non-NaN
values from a matrix and pass them into another matrix. The problem is that
I keep encountering an error message indicating the ":missing value where
TRUE/FALSE needed "
My code is as follows:
##Code Start
mat_zeroless<-matrix(NA,5000,2000) #generating holding matrix
##Assume source matrix containing combination of values, NaNs and zeros##
for (j in 1:5000)
{
for (k in 1:2000)
{
if(mat[j,k]!=0 & !is.NaN(mat[j,k])) {mat_zeroless[j,k]<-mat[j,k]}
}
}
##Code End
Error in if (mat[j,k] !=0 & !is.NaN(mat[j,k])) { :missing value where
TRUE/FALSE needed
I'm not sure how to resolve this.
rcoder
--
View this message in context:
http://www.nabble.com/missing-TRUE-FALSE-error-in-conditional-construct-tp18972244p18972244.html
Sent from the R help mailing list archive at Nabble.com.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
