[R] loop and plot

[joris meys]

Hi Rene,

two reasons :
- you have to specify the par first in your function, before plotting.
- you say for (i in length(f)), but length(f) is a vector with only
one value. The correct syntax is :

kk = function(f)
            {
             par(mfrow=c(1,length(f)))
             ls=as.character(f)
             for (i in 1:length(f))
             {
             pie(dataset.table[ls[i],],main=ls[i])
             box()
             }
             }

There is another important problem : this function only works if
dataset.table is specified in your environment. I would do something
like this :

dataset.table <-
table(data.frame(var1=c(1,2,3,1,2,3,1),colour=c("a","b","c","c","a","b","b")
))
kk = function(f,data=dataset.table)
            {
             par(mfrow=c(3,2))
             ls=as.character(f)
             for (i in 1:length(f))
             {
             pie(data[ls[i],],main=ls[i])
             box()
             }
             }

kk(1:3)

newdata <- table(data.frame(var1=c(1,2,3,1,2,3,1,2,3,1),colour=c("a","b","c","c","a","b","b","c","b","a")
))

kk(1:3,data=newdata)

This allows you to use the function on other datasets, but you don't
have to specify your default dataset each time.

Cheers
Joris

On Mon, Oct 19, 2009 at 1:33 PM, Rene <kaixinmalea at gmail.com> wrote:
> Thanks Joris for the prompt reply.
>
> I have tried to use par(mfrow=(3,3)), then I type kk(1:3), but it still ends
> up showing the last plot only instead of 3 plots.
>
> I think there must be sth wrong with my loop code, can you see where I did
> wrong?
>
> dataset.table <-
> table(data.frame(var1=c(1,2,3,1,2,3,1),colour=c("a","b","c","c","a","b","b")
> ))
> kk = function(f)
>             {
>              ls=as.character(f)
>              for (i in length(f))
>              {
>              pie(dataset.table[ls[i],],main=ls[i])
>              box()
>              }
>              }
> par(mfrow=(3,2))
> kk(1:3)
>
>
> Thanks a lot!
>
> Rene
>
>
> -----Original Message-----
> From: joris meys [mailto:jorismeys at gmail.com]
> Sent: Tuesday, 20 October 2009 12:11 a.m.
> To: Rene
> Subject: Re: [R] loop and plot
>
> Hi Rene,
>
> the problem is probably due to the fact that R will send all plots to
> the same graphical output window. Each next plot just replaces the
> previous one.
>
> if it's only a few plots, you can divide the graphical window with the
> commands par(mfrow=...) (see ?par) or layout(matrix(...)) (see
> ?layout). Otherwise you have to ask the window to wait before
> refreshing. par(ask=TRUE) (see ?par as well)
>
> Hope this helps
> Cheers
> Joris
>
> On Mon, Oct 19, 2009 at 12:14 PM, Rene <kaixinmalea at gmail.com> wrote:
>> Dear all,
>>
>> I am stuck at applying loop function for creating separated plots.
>>
>> I have coding like below:
>>
>> dataset.table <-
>>
> table(data.frame(var1=c(1,2,3,1,2,3,1),colour=c("a","b","c","c","a","b","b")
>> ))
>> kk = function(f)
>>             {
>>              ls=as.character(f)
>>              pie(dataset.table[ls,],main=ls)
>>              box()
>>             }
>>
>> kk(1)
>> kk(2)
>> kk(3)
>>
>> By using above code, I can create 3 single plot respectively, but when I
>> type kk(1:3), obviously it will not work.
>>
>> I know I have to vectorise the coding, then I can use command kk(1:3). I
> try
>> to use loop:
>>
>> kk = function(f)
>>             {
>>              ls=as.character(f)
>>              for (i in length(f))
>>              {
>>              pie(dataset.table[ls[i],],main=ls[i])
>>              box()
>>              }
>>              }
>> kk(1:3)
>>
>> the above code only gives me the last pie plot (ie. kk(3) plot) instead of
> 3
>> plots respectively.
>>
>> Can someone please guide me how to revise the loop coding, and produce 3
>> separated plots one after another on the screen by typing kk(1:3)?
>>
>> Thanks a lot.
>>
>> Rene.
>>
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>>
>
>