[R] Odp: Problem with outer()

[Petr PIKAL]

Hi

It is difficult to give some help as you did not provide any clue what the 
result shall be.
basically outer takes 2 vectors and evaluate function for each combination 
of elements in both vectors. However the function has to be vectorised and 
your function is not.

fff=function(x,y) {
+                       AA <- sign(x)
+                       BB <- sign(y)
+                       CC <- abs(y)
+                       DD1 <- mat1[,2]-mat1[1,1]
+                       DD2 <- mat2[,2]-mat2[1,1]
+                       EE <- (DD1 - 0) *AA + DD2*BB
+                       res1 <- mean(EE)/mat1[1,1]
+                       res2 <- ifelse(quantile(EE/mat1[1,1], 0.05) >
+ -0.65, quantile(EE/mat1[1,1], 0.05), paste("< -0.65"))
+                       return(paste(res1, res2, sep="--"))
+                     }
> fff(1:5, 3:8)
[1] "-2.22113283836956--< -0.65"
Warning messages:
1: In DD2 * BB :
  longer object length is not a multiple of shorter object length
2: In (DD1 - 0) * AA + DD2 * BB :
  longer object length is not a multiple of shorter object length

Therefore you need to redefine DD1, DD2 and EE computation.

Regards
Petr


r-help-bounces at r-project.org napsal dne 22.09.2010 10:18:07:

> Dear all, I have following piece of codes:
> 
> xx <- seq(-2,2, length.out=11)
> mat1 <- cbind(rep(43, 5), rnorm(5))
> mat2 <- cbind(rep(53, 5), rnorm(5))
> outer(c(1,-1), xx, function(x,y) {
>                       AA <- sign(x)
>                       BB <- sign(y)
>                       CC <- abs(y)
>                       DD1 <- mat1[,2]-mat1[1,1]
>                       DD2 <- mat2[,2]-mat2[1,1]
>                       EE <- (DD1 - 0) *AA + DD2*BB
>                       res1 <- mean(EE)/mat1[1,1]
>                       res2 <- ifelse(quantile(EE/mat1[1,1], 0.05) >
> -0.65, quantile(EE/mat1[1,1], 0.05), paste("< -0.65"))
>                       return(paste(res1, res2, sep="--"))
>                     }
>                   )
> 
> While running this code I am getting warnings as well as error:
> 
> > outer(c(1,-1), xx, function(x,y) {
> +                       AA <- sign(x)
> +                       BB <- sign(y)
> +                       CC <- abs(y)
> +                       DD1 <- mat1[,2]-mat1[1,1]
> +                       DD2 <- mat2[,2]-mat2[1,1]
> +                       EE <- (DD1 - 0) *AA + DD2*BB
> +                       res1 <- mean(EE)/mat1[1,1]
> +                       res2 <- ifelse(quantile(EE/mat1[1,1], 0.05) >
> -0.65, quantile(EE/mat1[1,1], 0.05), paste("< -0.65"))
> +                       return(paste(res1, res2, sep="--"))
> +                     }
> +                   )
> Error in dim(robj) <- c(dX, dY) :
>   dims [product 22] do not match the length of object [1]
> In addition: Warning messages:
> 1: In (DD1 - 0) * AA :
>   longer object length is not a multiple of shorter object length
> 2: In DD2 * BB :
>   longer object length is not a multiple of shorter object length
> 
> I am able to trace the warning, which comes from multiplication with
> AA & BB. However could not find the correct way to tackle this
> warning. Neither the error. Can somebody help me where I was wrong?
> 
> Thanks
> 
> ______________________________________________
> R-help at 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.