R: Saving JPEGS in R - r

Question

I am working with the R programming language.
I have the following dataset:
library(treemap)
library(dplyr)
var1 <- c("A", "B", "C", "D", "E")
var1<- sample(var1, 1000, replace=TRUE, prob=c(0.2, 0.2, 0.2, 0.2, 0.2))
var1<- as.factor(var1)
var2 <- c("abc", "bcd", "egf", "hiu", "lkj", "oiu", "piu", "xsr", "zze", "tre")
var2<- sample(var2, 1000, replace=TRUE, prob=c(0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1))
var2<- as.factor(var2)
my_data = data.frame(var1, var2)
my_data = data.frame(my_data %>% group_by(var1, var2) %>% summarise(counts = n()))
I am now using this code to make a treemap for the entire dataset:
resize.win <- function(Width=6, Height=6)
{
# works for windows
dev.off(); # dev.new(width=6, height=6)
windows(record=TRUE, width=Width, height=Height)
}
resize.win(10,10)
treemap(my_data, index = c("var1", "var2"), vSize = "counts", type = "index", palette = "Set1", title = "my map")
Now, I would like to make an individual treemap for each unique factor of var1 using a LOOP, and then save each of them. I tried to do this with a loop:
levs = my_data$var1
factors = lapply(levs[sapply(levs, is.factor)], levels)
factors = factors[[1]]
my_list = list()
for (i in 1:length(factors))
{
index_i = factors[[i]]
title_i = paste0("Tree Map", index_i)
data_i = my_data[which(my_data$var1 == index_i),]
treemap_i = treemap(data_i, index = c("var1", "var2"), vSize = "counts", type = "index",
palette = "Set1", title = title_i)
my_list[[i]] = treemap_i
save_title_i = paste0("treemap_",i, ".png")
png(save_title_i )
}
However, I don't think I am doing this right since the outputs are being corrupted:
Can someone please show me how to fix this?
Thanks!

Answer 1

If you want to save the plot locally you need to remember two things:
use png()(bmp, jpeg, pdf etc.) before the plot to open the file
use dev.off() after the plot to close the file
*In addition, you can change the dimensions of the plot you want to save by:
png(save_title_i , width = 800, height = 800)
for (i in 1:length(factors))
{
index_i = factors[[i]]
title_i = paste0("Tree Map", index_i)
data_i = my_data[which(my_data$var1 == index_i),]
save_title_i = paste0("treemap_",i, ".png")
png(save_title_i ) # open the file
treemap_i = treemap(data_i, index = c("var1", "var2"), vSize = "counts", type = "index", palette = "Set1", title = title_i)
my_list[[i]] = treemap_i
dev.off() # close the file
}