[R] Loop for main title in a plot

[David Winsemius]

On Apr 24, 2013, at 9:22 PM, Eva Günther wrote:

> Hi all,
> 
> I have a problem in including my plot in a loop. Here is a simple example
> for one plot:
> 
> # Plot simple graph with super- and subscript
> a<-c(1,2,3,4)
> b<-c(1,2,3,4)
> 
> plot(x=a,y=b,
>    ylab=expression(paste("Apple"["P"])),
>    xlab=expression(paste("Banana"^"th")),
>    main=expression(paste(italic("i-")~"4"^"th"~"choice")))
> 
> Now I would like to include the titel (main) as a function of the number of
> trails
> for (trial in 1:nTrials) {
> plot(
> 
> main=expression(paste(italic("i-")~"trial"^"th"~"choice")))
> 
> }
> 

I have not quite figured out what the exact goal is but this shows how to loop with expression that have evaluated component:  .... bquote is your friend:

for (trial in 1:length(a)) {
    plot(x=a,y=b,   # you were at the very least missing an x and y argument
        main=bquote( italic(i)-.(trial)^th~choice))
                            }

... and you had too many quoted elements. Plotmath `paste` is usually not needed. Learn to use * and ~.

David.

> e.g. nTrials = 5
> The title should look like this:
> 
> 5th plot: i ^th choice
> 4th plot: i-1 ^th choice
> 3th plot: i-2 ^th choice and so on
> 
> I have problems to create that, could you please help me?
> 
> Thank you!!
> 
> 	[[alternative HTML version deleted]]
> 
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David Winsemius
Alameda, CA, USA