R help - Apr 2010 - Unexpected warning from matplot

n <- 63
a <- 1:n
x <- a-1
y <- outer(x,a)
matplot(x,y,type='l')
Warning message:
In matplot(x, y, type = "l") :
   default 'pch' is smaller than number of columns and hence recycled

Why is it complaining if I specifically ask for type="l", so no pch 
involved?

Annoyance or feature?

The fix (if needed) is simple. In the matplot code change:

  if (is.null(pch)) {
to:
  if (is.null(pch) & (type[1] %in% c('p','b','o')))
{

Best regards
		mario

P.S.: R 2.9 on Win and Linux

-- 
Ing. Mario Valle
Data Analysis and Visualization Group            | 
http://www.cscs.ch/~mvalle
Swiss National Supercomputing Centre (CSCS)      | Tel:  +41 (91) 610.82.60
v. Cantonale Galleria 2, 6928 Manno, Switzerland | Fax:  +41 (91) 610.82.82

On 21.04.2010 16:36, Mario Valle wrote:
> n <- 63
> a <- 1:n
> x <- a-1
> y <- outer(x,a)
> matplot(x,y,type='l')
> Warning message:
> In matplot(x, y, type = "l") :
> default 'pch' is smaller than number of columns and hence recycled
>
> Why is it complaining if I specifically ask for type="l", so no
pch
> involved?
>
> Annoyance or feature?

Perhaps annoyance, if you like to be annoyed ... or just a warning that 
can be ignored since no pch is involved.

> The fix (if needed) is simple. In the matplot code change:
>
> if (is.null(pch)) {
> to:
> if (is.null(pch) & (type[1] %in%
c('p','b','o'))) {

Thanks, you meant && rather than &, I suppose.

>
> Best regards
> mario
>
> P.S.: R 2.9 on Win and Linux
>

Please always try the current prerelease (to be 2.11.0 tomorrow).

Best wishes,
Uwe Ligges