R help - Nov 2004 - Exporting to file: passing source name to file name in loop

Hi,

I'm having a mental block as to how I can automatically assign filenames
to the output of the following code. I am wishing to create a separate
.png file for every image created, each of them having a sequential
filename ie "sourcefile_index.png" so that I can create a movie from
them.

Please could someone tell me where I am going wrong?

the following code works fine and outputs to screen:

fun_pca_vector_movie_plot<-function(x,y,z,t){
zz=seq(1,(nrow(x)-t),by=t);jj=seq(t+1,(nrow(x)),by=t)
for(i in seq(along=zz)){
         pca<-prcomp(x[zz[i]:jj[i],], retx=T, center=T,scale=T)
        {
     par(mfrow=c(1,z))
      for(i in 1:z){
       image(east,north,t(map.matrix),col=my.colors,axes=T,
           xlab="",ylab="")
       text(y[,3],y[,2],labels=as.character(y[,1]))
       title(paste("Component",i,"Step:"))
        arrows(y[,3],y[,2],(y[,3]+50*(pca$rotation[i,1:(ncol(x)/2)])),
        (y[,2]+50*(pca$rotation[i,((ncol(x)/2)+1):(ncol(x))])),
        angle=30,length=0.05,code=2)
      }
     box()
    }
   }}

but when I try to save to file as follows it doesn't work:

fun_pca_vector_movie_plot<-function(x,y,z,t){
zz=seq(1,(nrow(x)-t),by=t);jj=seq(t+1,(nrow(x)),by=t)
for(i in seq(along=zz)){
      pca<-prcomp(x[zz[i]:jj[i],], retx=T, center=T,scale=T)
    {
     par(mfrow=c(1,z))
       for(i in 1:z){
       plot.new()
      
png(file=(paste(x".",i,"_",zz,".png",sep="")),width=240,height=240)
       image(east,north,t(map.matrix),col=my.colors,axes=T,
           xlab="",ylab="")
       text(y[,3],y[,2],labels=as.character(y[,1]))
       title(paste("Component",i,"Step:"))
        arrows(y[,3],y[,2],(y[,3]+50*(pca$rotation[i,1:(ncol(x)/2)])),
        (y[,2]+50*(pca$rotation[i,((ncol(x)/2)+1):(ncol(x))])),
        angle=30,length=0.05,code=2)
       dev.off()
      }
     box()
    }
   }}

many thanks in advance!
Laura Quinn
Institute of Atmospheric Science
School of Earth and Environment
University of Leeds
Leeds
LS2 9JT

tel: +44 113 343 1596
fax: +44 113 343 6716
mail: laura at env.leeds.ac.uk

What does `it doesn't work' actually mean?  Please read the posting
guide
and follow its advice.

Also, please show us readable and properly indented code, using spaces 
consistently.  (There is a chapter in `Writing R Extensions' showing you 
how to do this.)  I just cannot parse your code, and suspect you cannot 
either.

On Sun, 14 Nov 2004, Laura Quinn wrote:
> Hi,
>
> I'm having a mental block as to how I can automatically assign
filenames
> to the output of the following code. I am wishing to create a separate
> .png file for every image created, each of them having a sequential
> filename ie "sourcefile_index.png" so that I can create a movie
from
> them.
>
> Please could someone tell me where I am going wrong?
>
> the following code works fine and outputs to screen:
>
> fun_pca_vector_movie_plot<-function(x,y,z,t){
> zz=seq(1,(nrow(x)-t),by=t);jj=seq(t+1,(nrow(x)),by=t)
> for(i in seq(along=zz)){
>         pca<-prcomp(x[zz[i]:jj[i],], retx=T, center=T,scale=T)
>        {
>     par(mfrow=c(1,z))
>      for(i in 1:z){
>       image(east,north,t(map.matrix),col=my.colors,axes=T,
>           xlab="",ylab="")
>       text(y[,3],y[,2],labels=as.character(y[,1]))
>       title(paste("Component",i,"Step:"))
>        arrows(y[,3],y[,2],(y[,3]+50*(pca$rotation[i,1:(ncol(x)/2)])),
>        (y[,2]+50*(pca$rotation[i,((ncol(x)/2)+1):(ncol(x))])),
>        angle=30,length=0.05,code=2)
>      }
>     box()
>    }
>   }}
>
> but when I try to save to file as follows it doesn't work:
>
> fun_pca_vector_movie_plot<-function(x,y,z,t){
> zz=seq(1,(nrow(x)-t),by=t);jj=seq(t+1,(nrow(x)),by=t)
> for(i in seq(along=zz)){
>      pca<-prcomp(x[zz[i]:jj[i],], retx=T, center=T,scale=T)
>    {
>     par(mfrow=c(1,z))
>       for(i in 1:z){
>       plot.new()
>      
png(file=(paste(x".",i,"_",zz,".png",sep="")),width=240,height=240)
>       image(east,north,t(map.matrix),col=my.colors,axes=T,
>           xlab="",ylab="")
>       text(y[,3],y[,2],labels=as.character(y[,1]))
>       title(paste("Component",i,"Step:"))
>        arrows(y[,3],y[,2],(y[,3]+50*(pca$rotation[i,1:(ncol(x)/2)])),
>        (y[,2]+50*(pca$rotation[i,((ncol(x)/2)+1):(ncol(x))])),
>        angle=30,length=0.05,code=2)
>       dev.off()
>      }
>     box()
>    }
>   }}
>
> many thanks in advance!
> Laura Quinn
> Institute of Atmospheric Science
> School of Earth and Environment
> University of Leeds
> Leeds
> LS2 9JT
>
> tel: +44 113 343 1596
> fax: +44 113 343 6716
> mail: laura at env.leeds.ac.uk
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>
>
-- 
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

Apologies - Sunday afternoon coding, not my forte.

I am trying to pass the name of my input variable "x" (my.data) into
the
name of my output file, and am wanting to combine this with a "count"
value.

I hope that this code is a little more readable (though I seem to be
having problems pasting the formatting into my email composition):

fun_pca_vector_movie_plot <- function (x,y,z,t) {
  zz=seq(1,(nrow(x)-t),by=t);jj=seq(t+1,(nrow(x)),by=t)
    for(i in seq(along=zz)){
       plot.new()
	png(file=(paste(as.character(x),".",i,".png",sep="")),width=240,height=240)
        pca<-prcomp(x[zz[i]:jj[i],], retx=T, center=T,scale=T)
          {
           par(mfrow=c(1,z))
             for(i in 1:z){
                image(east,north,t(map.matrix),col=my.colors,axes=T,
                      xlab="",ylab="")
                text(y[,3],y[,2],labels=as.character(y[,1]))
                title(paste("Component",i,"Step:"))
              	arrows(y[,3],y[,2],(y[,3]+50*(pca$rotation[i,1:(ncol(x)/2)])),
                      (y[,2]+50*(pca$rotation[i,((ncol(x)/2)+1):(ncol(x))])),
                       angle=30,length=0.05,code=2)
            }
         box()
         }
       dev.off()
     }
   }

I get a "syntax error" relating to the as.character(x) part of the
file
name - if I remove this, the code works fine for the rest of the file
extension. I have tried deparse(x) but this returns a file extension of
the following nature:

structure(list(f1 = c(5.56358661715647, 6.10364037003176,
6.24040147126807, .10.png

Thanks,
Laura

Laura Quinn
Institute of Atmospheric Science
School of Earth and Environment
University of Leeds
Leeds
LS2 9JT

tel: +44 113 343 1596
fax: +44 113 343 6716
mail: laura at env.leeds.ac.uk