Printing multiple ggplots into a single pdf, multiple plots per page - r

I have a list, p, where each element of p is a list of ggplot2 plotting objects.
I would like to output a single pdf containing all the plots in p such that the plots in p[[1]] are on page 1, the plots in p[[2]] are on page 2, etc. How might I do this?
Here's some example code to provide you with the data structure I'm working with--apologies for the boring plots, I picked variables at random.
require(ggplot2)
p <- list()
cuts <- unique(diamonds$cut)
for(i in 1:length(cuts)){
p[[i]] <- list()
dat <- subset(diamonds, cut==cuts[i])
p[[i]][[1]] <- ggplot(dat, aes(price,table)) + geom_point() +
opts(title=cuts[i])
p[[i]][[2]] <- ggplot(dat, aes(price,depth)) + geom_point() +
opts(title=cuts[i])
}

This solution is independent of whether the lengths of the lists in the list p are different.
library(gridExtra)
pdf("plots.pdf", onefile = TRUE)
for (i in seq(length(p))) {
do.call("grid.arrange", p[[i]])
}
dev.off()
Because of onefile = TRUE the function pdf saves all graphics appearing sequentially in the same file (one page for one graphic).

Here is the most elegant solution to exporting a list of ggplot objects into a single pdf file using ggplot2::ggsave() and gridExtra::marrangeGrob().
library(ggplot2)
library(gridExtra)
Let's say you create multiple plots using lapply()
p <- lapply(names(mtcars), function(x) {
ggplot(mtcars, aes_string(x)) +
geom_histogram()
})
Save list of p plots:
ggsave(
filename = "plots.pdf",
plot = marrangeGrob(p, nrow=1, ncol=1),
width = 15, height = 9
)

Here is a simpler version of Sven's solution for the R beginners who would otherwise blindly use the do.call and nested lists that they neither need nor understand. I have empirical evidence. :)
library(ggplot2)
library(gridExtra)
pdf("plots.pdf", onefile = TRUE)
cuts <- unique(diamonds$cut)
for(i in 1:length(cuts)){
dat <- subset(diamonds, cut==cuts[i])
top.plot <- ggplot(dat, aes(price,table)) + geom_point() +
opts(title=cuts[i])
bottom.plot <- ggplot(dat, aes(price,depth)) + geom_point() +
opts(title=cuts[i])
grid.arrange(top.plot, bottom.plot)
}
dev.off()

I've tried some of these solutions but with no success. I researched a little more and found a solution that worked perfectly for me. It saves all my graphics in a single pdf file, each chart on one page.
library(ggplot2)
pdf("allplots.pdf",onefile = TRUE)
for(i in glist){
tplot <- ggplot(df, aes(x = as.factor(class), y = value))
print(tplot)
}
dev.off()

Here's one solution, but I don't particularly like it:
ggsave("test.pdf", do.call("marrangeGrob", c(unlist(p,recursive=FALSE),nrow=2,ncol=1)))
The problem is that it relies on there being the same number of plots in each group. If all(sapply(p, length) == 2) were false, then it would break.

A solution that worked for me with ggpubr package (package on Github, code for installation: devtools::install_github("kassambara/ggpubr")).
Let's say you have 4 plots p1, p2, p3 and p4.
library(ggpubr)
multi.page <- ggarrange(p1,p2,p3,p4, nrow=1, ncol=1) # for one plot per page
multi.page[[1]] # for seeing the first plot
ggexport(multi.page, filename="my-plots.pdf")
More examples of ggpubr use: http://www.sthda.com/english/articles/24-ggpubr-publication-ready-plots/81-ggplot2-easy-way-to-mix-multiple-graphs-on-the-same-page/

Here's a function based on Sven's approach, including the roxygen2 documentation and an example.
#' Save list of ggplot2 objects to single pdf
#'
#' #param list (list) List of ggplot2 objects.
#' #param filename (chr) What to call the pdf.
#'
#' #return Invisible NULL.
#' #export
#'
#' #examples
#' #plot histogram of each numeric variable in iris
#' list_iris = map(names(iris[-5]), ~ggplot(iris, aes_string(.)) + geom_histogram())
#' #save to a single pdf
#' GG_save_pdf(list_iris, "test.pdf")
GG_save_pdf = function(list, filename) {
#start pdf
pdf(filename)
#loop
for (p in list) {
print(p)
}
#end pdf
dev.off()
invisible(NULL)
}

A nice solution without the gridExtra package:
library(plyr)
library(ggplot2)
li = structure(p, class = c("gglist", "ggplot"))
print.gglist = function(x, ...) l_ply(x, print, ...)
ggsave(li, file = "test.pdf")

Related

Why does ggplotly does not work in rmarkdown the same way ggplot does

I would like to use ggplotly for it's side effect the same way ggplot does or even graphics does. By this I mean when I knitr::knit or rmarkdown::render a Rmd document I expect print(obj) where obj is a ggplotly objcet to be in the report and that's not the case.
Can anyone explain what is going on?
Can anyone tell me how I can achieve want I want to do. I want to be able to plot a ggplotly graph into a function without returning the object (I want to return the underlying data of the graph) and I'd like the code to work for both ggplot and ggplotly (i.e. use the same code for a ggplot or ggplotly)
question.R file
#+ libs, echo = FALSE
suppressMessages({
library(ggplot2)
library(plotly)
library(rmarkdown)
})
#+ functions decl, echo = FALSE
df <- data.frame(x = 1:5, y = 1:5)
f_0 <- function(df) {
p <- ggplot(df, aes(x, y)) + geom_line()
# p or plot(p) or print(p) works
print(p)
return(df)
}
f_1 <- function(df) {
p <- ggplot(df, aes(x, y)) + geom_line()
p <- ggplotly(p)
# plot(p) crashes
# print p does not print in report
print(p)
# p standalone does not work either
p
return(df)
}
#' # plots
#' plot 0
#+ plot_0
res_0 <- f_0(df)
#' plot 1
#+ plot_1
res_1 <- f_1(df)
Render this file
rmarkdown::render("question.R")
The output
Editorial comment: As a point of style, it's usually a good idea to separate computation and plotting into distinct functions, because it increases modularity, makes code easier to maintain, and allows for finer control without parameter creep. The output of individual functions can then be easily mapped to separate knitr chunks.
Best solution: I know that you are specifically asking about not returning the plot object, but I just want to point out that returning it alongside the results provides the cleanest and most elegant solution:
---
output: html_document
---
```{r include=FALSE}
library( tidyverse )
df <- data_frame( x=1:5, y=1:5 )
```
```{r}
f <- function(df) {
gg <- ggplot(df, aes(x,y)) + geom_point()
list( result=df, plot=plotly::ggplotly(gg) )
}
res <- f(df)
res$plot
```
However, if you absolutely cannot return a plotly object from a function, you have some alternatives.
Option 1: Store the plotly object to the parent frame, providing access to it from the knitr chunk.
```{r}
f1 <- function(df) {
gg <- ggplot(df, aes(x,y)) + geom_point()
assign("ggp", plotly::ggplotly(gg), envir=parent.frame())
df # NOT returning a plot
}
res1 <- f1(df)
ggp # Let knitr handle the rendering naturally
```
Option 2: Render the plot to a temporary .html and then import it as an iframe
```{r, results='asis'} # <-- note the "asis" chunk option
f2 <- function(df)
{
gg <- ggplot(df, aes(x,y)) + geom_point()
htmlwidgets::saveWidget( plotly::ggplotly(gg), "temp.html")
print( htmltools::tags$iframe(src="temp.html", width=640, height=480) )
df # NOT returning a plot
}
res2 <- f2(df)
```
Explanation: Yihui can correct me if I'm wrong, but knitr basically does "Option 2" behind the scenes. It renders htmlwidgets, such as plotly objects, into temporary .html files and then combines those temporaries to produce the final document. The reason it fails inside a function is because the temporary file gets deleted when execution leaves the function scope. (You can replicate this yourself by using tempfile() instead of the persistent "temp.html"; the iframe object will display a "file not found" error in the final document.) There's probably a way to modify knitr hooks to retain the temporary files, but it's beyond my knowledge. Lastly, the reason you don't have this issue with basic ggplot objects is because their output goes to the plotting device, which persists across calling frames.

ocpu.rplot() show R ggplot on html without labels but opencpu API results have

I can get correct R plots with text labels (ggplot and ggrepel) from a remote R plot function through opencpu API, but get wrong plots through ocpu.rplot call, using opencpu-0.4.js, with the same remote R plot function. The wrong plot got no text labels on them.
I write a small reproducible example for this problem:
HTML code: https://github.com/cywhale/ODB/blob/master/opencpu_test/ocpu_test.html
in this html js, use opcu.call rplot to call plot_test API to plot, and session.getLoc() to get R graphics in R/.val/png, put both two graphics in the same html
Run this html and get the reproducible results on my server:
https://bio.odb.ntu.edu.tw/test/ocpu_test.html
A remote R plot function : plot_test()
#' generate a test graph by ggplot+ggrepel, use offical ex: https://cran.r-project.org/web/packages/ggrepel/vignettes/ggrepel.html
#' #return A ggplot graph
#' #examples plot_test()
#' #rdname plot_test
#' #export
plot_test <- function() {
set.seed(42)
data("mtcars")
dat2 <- subset(mtcars, wt > 3 & wt < 4)
# Hide all of the text labels.
dat2$car <- ""
# Let's just label these items.
ix_label <- c(2,3,16)
dat2$car[ix_label] <- rownames(dat2)[ix_label]
g1 <- ggplot(dat2, aes(wt, mpg, label = car)) +
geom_point(color = ifelse(dat2$car == "", "grey50", "red")) +
geom_text_repel()
print(g1)
}
The two graphics are different. The texts and labels that use ggrepel package disappear in ocpu.call rplot. But in R/.val/png, the graphics is correct. Expect that ocpu.call rplot should return the correct plot with labels as the results in R/.val/png. Appreciate any comments that may help to clarify or solve this problem. Thanks.

Saving ggplot graphs to pdf not formatting correctly in PDF

This is a follow on question to my original here
I am currently trying to save the outputs of a ggplot graph to .pdf but I am running into some problems.
I run the following on the dput data on the original question (I repaste everything below).
library(gridExtra)
pdf("Plots.pdf", onefile = TRUE)
for(j in 1:length(plotList)) {
grid.arrange(plotList[[j]], nrow = 2)
}
dev.off()
This saves the files as a pdf document but instead of getting two graphs per page I get one graph which takes up half a page. Is it possible to resize the graphs, when I select nrow = 3 I get the same problem, I get one graph in the top 3rd / half of the page and a blank space for the rest. I provide a screen shot of the output:
Here is a minimal example:
# Make empty list for plots
plotList <- list()
# Build plots
library(ggplot2)
for(i in 1:2){
plotList[[i]] <-
ggplot(mtcars, aes(mpg, cyl)) +
geom_point() +
labs(title = i)
}
# Save plots
library(gridExtra)
pdf("Plots.pdf", onefile = TRUE)
for(j in 1:length(plotList)) {
grid.arrange(plotList[[j]], nrow = 2)
}
dev.off()
Credit to #LachlanO
You problem comes from how you are calling grid.arrange. By including it in a loop, you are telling it to create multiple separate plots, like this:
grid.arrange(plotList[[1]], nrow = 2)
grid.arrange(plotList[[2]], nrow = 2)
grid.arrange(plotList[[3]], nrow = 2)
What you actually are trying to do is create one grid.arrange object which contains all the plots. To do this, you need call the function against the list:
do.call("grid.arrange", c(plotList, nrow=2))
Alternatively, you can use the cowplot package and use:
cowplot::plot_grid(plotlist = plotList, nrow = 2)
So to save the PDF you can use:
pdf("Plots.pdf", onefile = TRUE)
do.call("grid.arrange", c(plotList, nrow=2))
dev.off()

Export R plot to multiple formats

Since it is possible to export R plots to PDF or PNG or SVG etc., is it also possible to export an R plot to multiple formats at once? E.g., export a plot to PDF and PNG and SVG without recalculating the plot?
Without using ggplot2 and other packages, here are two alternative solutions.
Create a function generating a plot with specified device and sapply it
# Create pseudo-data
x <- 1:10
y <- x + rnorm(10)
# Create the function plotting with specified device
plot_in_dev <- function(device) {
do.call(
device,
args = list(paste("plot", device, sep = ".")) # You may change your filename
)
plot(x, y) # Your plotting code here
dev.off()
}
wanted_devices <- c("png", "pdf", "svg")
sapply(wanted_devices, plot_in_dev)
Use the built-in function dev.copy
# With the same pseudo-data
# Plot on the screen first
plot(x, y)
# Loop over all devices and copy the plot there
for (device in wanted_devices) {
dev.copy(
eval(parse(text = device)),
paste("plot", device, sep = ".") # You may change your filename
)
dev.off()
}
The second method may be a little tricky because it requires non-standard evaluation. Yet it works as well. Both methods work on other plotting systems including ggplot2 simply by substituting the plot-generating codes for the plot(x, y) above - you probably need to print the ggplot object explicitly though.
Yes, absolutely! Here is the code:
library(ggplot2)
library(purrr)
data("cars")
p <- ggplot(cars, aes(speed, dist)) + geom_point()
prefix <- file.path(getwd(),'test.')
devices <- c('eps', 'ps', 'pdf', 'jpeg', 'tiff', 'png', 'bmp', 'svg', 'wmf')
walk(devices,
~ ggsave(filename = file.path(paste(prefix, .x)), device = .x))

plotting a list of grobs

DISCLOSURE: I'm not sure how to make a reproducible example for this question.
I'm trying to plot a list of grobs using the gridExtra package.
I have some code that looks like this:
## Make Graphic Objects for Spec and raw traces
for (i in 1:length(morletPlots)){
gridplots_Spec[[i]]=ggplotGrob(morletPlots[[i]])
gridplots_Raw[[i]]=ggplotGrob(rawPlot[[i]])
gridplots_Raw[[i]]$widths=gridplots_Spec[[i]]$widths
}
names(gridplots_Spec)=names(morletPlots)
names(gridplots_Raw)=names(rawPlot)
## Combine spec and Raw traces
g=list()
for (i in 1:length(rawPlot)){
g[[i]]=arrangeGrob(gridplots_Spec[i],gridplots_Raw[i],heights=c(4/5,1/5))
}
numPlots = as.numeric(length(g))
##Plot both
for (i in 1:numPlots){
grid.draw(g[i],ncol=2)
}
Let me walk through the code.
morletPlots = a list of ggplots
rawplot = A list of ggplots
gridplots_spec and gridplots_Raw = list of grobs from the ggplots made above.
g = a list of the two grobs above combined so combining gridplots_spec[1] and gridplots_raw[1] so on and so on for the length of the list.
now my goal would be two plot all of those into 2 columns. But whenever I pass the gridplots_spec[i] through the grid.draw loop I get an error:
Error in UseMethod("grid.draw") :
no applicable method for 'grid.draw' applied to an object of class "list"
I can't unlist it becasue it just turns into a long character vector. any ideas?
If it's absolutely crucial I can spend the time to make an reproducible example but I'm more likely just missing a simple step.
Here's my interpretation of your script, if it's not the intended result you may want to use some bits and pieces to make your question reproducible.
library(grid)
library(gridExtra)
library(ggplot2)
morletPlots <- replicate(5, ggplot(), simplify = FALSE)
rawplot <- replicate(5, ggplot(), simplify = FALSE)
glets <- lapply(morletPlots, ggplotGrob)
graws <- lapply(rawplot, ggplotGrob)
rawlet <- function(raw, let, heights=c(4,1)){
g <- rbind(let, raw)
panels <- g$layout[grepl("panel", g$layout$name), ]
# g$heights <- grid:::unit.list(g$heights) # not needed
g$heights[unique(panels$t)] <- lapply(heights, unit, "null")
g
}
combined <- mapply(rawlet, raw = graws, let=glets, SIMPLIFY = FALSE)
grid.newpage()
grid.arrange(grobs=combined, ncol=2)
Edit I can't resist this mischievous hack to colour the plots for illustration; feel free to ignore it.
palette(RColorBrewer::brewer.pal(8, "Pastel1"))
ggplot.numeric = function(i) ggplot2::ggplot() +
theme(panel.background=element_rect(fill=i))
morletPlots <- lapply(1:5, ggplot)
rawplot <- lapply(1:5, ggplot)

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