CODEWITHSUNDEEP
rlistfunctionggplot2
K.Hua
K.Hua

Reputation: 799

R function list with undetermined length as an argument

I am using the multiplot function of this website

This function takes as argument an indefinite number of plots and plot them together. With the code below I can plot for example 4 plots together in 2 columns.

library(ggplot2)
n = 4
p = lapply(1:n, function(i) {
    ggplot(data.frame(x = 1:10,y = rep(i,10)), aes(x = x, y = y)) +
    geom_point()
})

multiplot(p[[1]],p[[2]],p[[3]],p[[4]],cols = 2)

How can I do if I have an undetermined number of plots n ?

I already tried things like 

multiplot(p,cols = 2)
do.call(multiplot, list(p,cols = 2))

but it doesn't give the result that I want

Upvotes: 2

Views: 95

Answers (2)

Julius Vainora
Julius Vainora

Reputation: 48221

With the second option you were also close:

do.call(multiplot, c(p, cols = 2))

does the job since

length(list(p, cols = 2))
# [1] 2
length(c(p, cols = 2))
# [1] 5

That is, list(p, cols = 2) makes a list of two components: a list p and an integer 2, while what you want is to extend p by adding cols = 2, and we need for that. (Somewhat not immediately obvious perhaps, but the title of ?c does indeed say Combine Values into a Vector or List.)

Upvotes: 2

lemairev
lemairev

Reputation: 216

maybe multiplot(plotlist = p) ! cheers

Upvotes: 2

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