Related
I plot a simple linear regression using R.
I would like to save that image as PNG or JPEG, is it possible to do it automatically? (via code)
There are two different questions: First, I am already looking at the plot on my monitor and I would like to save it as is. Second, I have not yet generated the plot, but I would like to directly save it to disk when I execute my plotting code.
There are two closely-related questions, and an answer for each.
1. An image will be generated in future in my script, how do I save it to disk?
To save a plot, you need to do the following:
Open a device, using png(), bmp(), pdf() or similar
Plot your model
Close the device using dev.off()
Some example code for saving the plot to a png file:
fit <- lm(some ~ model)
png(filename="your/file/location/name.png")
plot(fit)
dev.off()
This is described in the (combined) help page for the graphical formats ?png, ?bmp, ?jpeg and ?tiff as well as in the separate help page for ?pdf.
Note however that the image might look different on disk to the same plot directly plotted to your screen, for example if you have resized the on-screen window.
Note that if your plot is made by either lattice or ggplot2 you have to explicitly print the plot. See this answer that explains this in more detail and also links to the R FAQ: ggplot's qplot does not execute on sourcing
2. I'm currently looking at a plot on my screen and I want to copy it 'as-is' to disk.
dev.print(pdf, 'filename.pdf')
This should copy the image perfectly, respecting any resizing you have done to the interactive window. You can, as in the first part of this answer, replace pdf with other filetypes such as png.
If you want to keep seeing the plot in R, another option is to use dev.copy:
X11 ()
plot (x,y)
dev.copy(jpeg,filename="plot.jpg");
dev.off ();
If you reach a clutter of too many plot windows in R, use graphics.off() to close all of the plot windows.
If you use ggplot2 the preferred way of saving is to use ggsave. First you have to plot, after creating the plot you call ggsave:
ggplot(...)
ggsave("plot.png")
The format of the image is determined by the extension you choose for the filename. Additional parameters can be passed to ggsave, notably width, height, and dpi.
Like this
png('filename.png')
# make plot
dev.off()
or this
# sometimes plots do better in vector graphics
svg('filename.svg')
# make plot
dev.off()
or this
pdf('filename.pdf')
# make plot
dev.off()
And probably others too. They're all listed together in the help pages.
For the first question, I find dev.print to be the best when working interactively. First, you set up your plot visually and when you are happy with what you see, you can ask R to save the current plot to disk
dev.print(pdf, file="filename.pdf");
You can replace pdf with other formats such as png.
This will copy the image exactly as you see it on screen. The problem with dev.copy is that the image is often different and doesn't remember the window size and aspect ratio - it forces the plot to be square by default.
For the second question, (as others have already answered), you must direct the output to disk before you execute your plotting commands
pdf('filename.pdf')
plot( yourdata )
points (some_more_data)
dev.off() # to complete the writing process and return output to your monitor
If you use R Studio http://rstudio.org/ there is a special menu to save you plot as any format you like and at any resolution you choose
If you open a device using png(), bmp(), pdf() etc. as suggested by Andrie (the best answer), the windows with plots will not pop up open, just *.png, *bmp or *.pdf files will be created. This is convenient in massive calculations, since R can handle only limited number of graphic windows.
However, if you want to see the plots and also have them saved, call savePlot(filename, type) after the plots are drawn and the window containing them is active.
plotpath<- file.path(path, "PLOT_name",paste("plot_",file,".png",sep=""))
png(filename=plotpath)
plot(x,y, main= file)
dev.off()
To add to these answers, if you have an R script containing calls that generate plots to screen (the native device), then these can all be saved to a pdf file (the default device for a non-interactive shell) "Rplots.pdf" (the default name) by redirecting the script into R from the terminal (assuming you are running linux or OS X), e.g.:
R < myscript.R --no-save
This could be converted to jpg/png as necessary
In some cases one wants to both save and print a base r plot. I spent a bit of time and came up with this utility function:
x = 1:10
basesave = function(expr, filename, print=T) {
#extension
exten = stringr::str_match(filename, "\\.(\\w+)$")[, 2]
switch(exten,
png = {
png(filename)
eval(expr, envir = parent.frame())
dev.off()
},
{stop("filetype not recognized")})
#print?
if (print) eval(expr, envir = parent.frame())
invisible(NULL)
}
#plots, but doesn't save
plot(x)
#saves, but doesn't plot
png("test.png")
plot(x)
dev.off()
#both
basesave(quote(plot(x)), "test.png")
#works with pipe too
quote(plot(x)) %>% basesave("test.png")
Note that one must use quote, otherwise the plot(x) call is run in the global environment and NULL gets passed to basesave().
dev.copy(png,'path/pngFile.png')
plot(YData ~ XData, data = mydata)
dev.off()
I plot a simple linear regression using R.
I would like to save that image as PNG or JPEG, is it possible to do it automatically? (via code)
There are two different questions: First, I am already looking at the plot on my monitor and I would like to save it as is. Second, I have not yet generated the plot, but I would like to directly save it to disk when I execute my plotting code.
There are two closely-related questions, and an answer for each.
1. An image will be generated in future in my script, how do I save it to disk?
To save a plot, you need to do the following:
Open a device, using png(), bmp(), pdf() or similar
Plot your model
Close the device using dev.off()
Some example code for saving the plot to a png file:
fit <- lm(some ~ model)
png(filename="your/file/location/name.png")
plot(fit)
dev.off()
This is described in the (combined) help page for the graphical formats ?png, ?bmp, ?jpeg and ?tiff as well as in the separate help page for ?pdf.
Note however that the image might look different on disk to the same plot directly plotted to your screen, for example if you have resized the on-screen window.
Note that if your plot is made by either lattice or ggplot2 you have to explicitly print the plot. See this answer that explains this in more detail and also links to the R FAQ: ggplot's qplot does not execute on sourcing
2. I'm currently looking at a plot on my screen and I want to copy it 'as-is' to disk.
dev.print(pdf, 'filename.pdf')
This should copy the image perfectly, respecting any resizing you have done to the interactive window. You can, as in the first part of this answer, replace pdf with other filetypes such as png.
If you want to keep seeing the plot in R, another option is to use dev.copy:
X11 ()
plot (x,y)
dev.copy(jpeg,filename="plot.jpg");
dev.off ();
If you reach a clutter of too many plot windows in R, use graphics.off() to close all of the plot windows.
If you use ggplot2 the preferred way of saving is to use ggsave. First you have to plot, after creating the plot you call ggsave:
ggplot(...)
ggsave("plot.png")
The format of the image is determined by the extension you choose for the filename. Additional parameters can be passed to ggsave, notably width, height, and dpi.
Like this
png('filename.png')
# make plot
dev.off()
or this
# sometimes plots do better in vector graphics
svg('filename.svg')
# make plot
dev.off()
or this
pdf('filename.pdf')
# make plot
dev.off()
And probably others too. They're all listed together in the help pages.
For the first question, I find dev.print to be the best when working interactively. First, you set up your plot visually and when you are happy with what you see, you can ask R to save the current plot to disk
dev.print(pdf, file="filename.pdf");
You can replace pdf with other formats such as png.
This will copy the image exactly as you see it on screen. The problem with dev.copy is that the image is often different and doesn't remember the window size and aspect ratio - it forces the plot to be square by default.
For the second question, (as others have already answered), you must direct the output to disk before you execute your plotting commands
pdf('filename.pdf')
plot( yourdata )
points (some_more_data)
dev.off() # to complete the writing process and return output to your monitor
If you use R Studio http://rstudio.org/ there is a special menu to save you plot as any format you like and at any resolution you choose
If you open a device using png(), bmp(), pdf() etc. as suggested by Andrie (the best answer), the windows with plots will not pop up open, just *.png, *bmp or *.pdf files will be created. This is convenient in massive calculations, since R can handle only limited number of graphic windows.
However, if you want to see the plots and also have them saved, call savePlot(filename, type) after the plots are drawn and the window containing them is active.
plotpath<- file.path(path, "PLOT_name",paste("plot_",file,".png",sep=""))
png(filename=plotpath)
plot(x,y, main= file)
dev.off()
To add to these answers, if you have an R script containing calls that generate plots to screen (the native device), then these can all be saved to a pdf file (the default device for a non-interactive shell) "Rplots.pdf" (the default name) by redirecting the script into R from the terminal (assuming you are running linux or OS X), e.g.:
R < myscript.R --no-save
This could be converted to jpg/png as necessary
In some cases one wants to both save and print a base r plot. I spent a bit of time and came up with this utility function:
x = 1:10
basesave = function(expr, filename, print=T) {
#extension
exten = stringr::str_match(filename, "\\.(\\w+)$")[, 2]
switch(exten,
png = {
png(filename)
eval(expr, envir = parent.frame())
dev.off()
},
{stop("filetype not recognized")})
#print?
if (print) eval(expr, envir = parent.frame())
invisible(NULL)
}
#plots, but doesn't save
plot(x)
#saves, but doesn't plot
png("test.png")
plot(x)
dev.off()
#both
basesave(quote(plot(x)), "test.png")
#works with pipe too
quote(plot(x)) %>% basesave("test.png")
Note that one must use quote, otherwise the plot(x) call is run in the global environment and NULL gets passed to basesave().
dev.copy(png,'path/pngFile.png')
plot(YData ~ XData, data = mydata)
dev.off()
I have a folder with multiple JPEG files. How do I generate a PDF file from these JPEGs in R?
One JPEG = 1 PDF page. Images are of the same size.
Thanks a lot in advance.
You can do this easily using Latex. Which is nice, because then you can just use Sweave to do the whole thing.
You can do something along the lines of :
% This is some Sweave file
\documentclass{article}
\usepackage{graphicx}
\begin{document}
<<results=tex,echo=FALSE>>=
mypics <- dir('mypics')
for(i in mypics){
cat("\\includegraphics{", i, "}\n\n", sep = "")
}
#
\end{document}
OK, you'll have to set up your Sweave pipeline, but with a bit of tweaking you can automate the whole process easily.
if you insist on using R (other tools are more suitable), try something like this (slow, untested):
lf = list.files(pattern = "jpeg") # image filenames
library(jpeg)
jpegs = lapply(lf, readJPG)
library(grid)
pdf("output.pdf", width=8, height=4)
grid.raster(jpegs[[1]])
lapply(jpegs[-1], function(x) {grid.newpage() ; grid.raster(x)} ) -> bquiet
dev.off()
If you insist on using R to do this then you can open a pdf plotting device, par to set the margins (default will probably be to big and not centering), then in a loop use plot.new to start a new page and plot.window to set up the coordinates, etc. without plotting axes etc., use the read.jpeg function from the ReadImages package (or other tool/package to read, EBImage is another possibility) then rasterImage to plot the jpeg to the pdf device (or replace some of those steps with other image plotting functions, such as the plot method in ReadImages).
But overall it is probably easier/quicker/better/... to use a tool better designed for this type of thing. The ImageMagick suite of programs comes to mind, LaTeX has also been mentioned, and there are probably other tools as well.
I am currently working on CGH array results, which involve several plots of dozens of thousands of points, and i would like to benefit from the multiple page feature of the PDF device and the lightness of the PNG image format.
The problem is that the PDF device stores the plots as vectorial drawings, so the PDF files are huge and take several minutes to open. I wonder if R can plot as multiple bitmaps embedded in a single PDF file, as i know the PDF format able to handle it.
Here is a simple example, the PDF file is about 2 Mo while the png ones are about 10 Ko, so I'd like a PDF file of about 20 Ko.
png("test%i.png")
plot(rnorm(2e4), rnorm(2e4), pch="+", cex=0.6)
plot(rnorm(2e4), rnorm(2e4), pch="+", cex=0.6)
dev.off()
pdf("test.pdf", onefile=TRUE)
plot(rnorm(2e4), rnorm(2e4), pch="+", cex=0.6)
plot(rnorm(2e4), rnorm(2e4), pch="+", cex=0.6)
dev.off()
Use the png driver to create a PNG file of an acceptable resolution. Make your plot to that. Close the png device.
Then use readPNG from package:png to read it in.
Next open a PDF driver, create a blank plot with no margins and bounds at (0,0) (1,1) and draw the png to that using rasterImage. Add extra pages by creating fresh plots. Close PDF driver.
That should give you a PDF with bitmapped versions of the plots. There's a few tricky bits in getting the plots set up right, and the png resolution is crucial, but I think the above has all the ingredients.
> png("plot.png")
> makeplot(100000) # simple function that plots 100k points
> dev.off()
X11cairo
2
> plotPNG = readPNG("plot.png")
> pdf("plot.pdf")
> par(mai=c(0,0,0,0))
> plot(c(0,1),c(0,1),type="n")
> rasterImage(plotPNG,0,0,1,1)
> dev.off()
Then check plot.pdf...
Here's a solution that gets you close (50kb) to your desired file size (25kb), without requiring you to install LaTeX and/or learn Sweave. (Not that either of those are undesirable in the long-run!)
It uses the grid functions grid.cap() and grid.raster(). More details and ideas are in a recent R-Journal article by Paul Murrell (warning : PDF):
require(grid)
# Make the plots
dev.new() # Reducing width and height of this device will produce smaller raster files
plot(rnorm(2e4), rnorm(2e4), pch="+", cex=0.6)
cap1 <- grid.cap()
plot(rnorm(2e4), rnorm(2e4), pch="+", cex=0.6, col="red")
cap2 <- grid.cap()
dev.off()
# Write them to a pdf
pdf("test.pdf", onefile=TRUE)
grid.raster(cap1)
plot.new()
grid.raster(cap2)
dev.off()
The resulting pdf images appear to retain more detail than your files test1.png and test2.png, so you could get even closer to your goal by trimming down their resolution.
To include multiple plots in your pdf, set onefile = TRUE.
pdf("test.pdf", onefile = TRUE)
plot(1:5)
plot(6:10)
dev.off()
To make those plots PNGs rather than native PDF plots will require a tiny bit more effort. Create all your plots as PNGs, like so:
png("test%01d.png")
plot(1:5)
plot(6:10)
dev.off()
Then create a LaTeX document that includes those PNGs. You can do that from R by using Sweave (but how to do that is big enough to be its own question). There's a decent introductory example here.
How abouta Sweave solution?
\documentclass[a4paper]{article}
\usepackage[OT1]{fontenc}
\usepackage{Sweave}
\SweaveOpts{pdf = FALSE, eps = FALSE}
\DeclareGraphicsExtensions{.png}
\begin{document}
\title{Highly imaginative title}
\author{romunov}
\maketitle
<<fig = TRUE, png = TRUE, echo = FALSE>>=
plot(1:10, 1:10)
#
\end{document}
I plot a simple linear regression using R.
I would like to save that image as PNG or JPEG, is it possible to do it automatically? (via code)
There are two different questions: First, I am already looking at the plot on my monitor and I would like to save it as is. Second, I have not yet generated the plot, but I would like to directly save it to disk when I execute my plotting code.
There are two closely-related questions, and an answer for each.
1. An image will be generated in future in my script, how do I save it to disk?
To save a plot, you need to do the following:
Open a device, using png(), bmp(), pdf() or similar
Plot your model
Close the device using dev.off()
Some example code for saving the plot to a png file:
fit <- lm(some ~ model)
png(filename="your/file/location/name.png")
plot(fit)
dev.off()
This is described in the (combined) help page for the graphical formats ?png, ?bmp, ?jpeg and ?tiff as well as in the separate help page for ?pdf.
Note however that the image might look different on disk to the same plot directly plotted to your screen, for example if you have resized the on-screen window.
Note that if your plot is made by either lattice or ggplot2 you have to explicitly print the plot. See this answer that explains this in more detail and also links to the R FAQ: ggplot's qplot does not execute on sourcing
2. I'm currently looking at a plot on my screen and I want to copy it 'as-is' to disk.
dev.print(pdf, 'filename.pdf')
This should copy the image perfectly, respecting any resizing you have done to the interactive window. You can, as in the first part of this answer, replace pdf with other filetypes such as png.
If you want to keep seeing the plot in R, another option is to use dev.copy:
X11 ()
plot (x,y)
dev.copy(jpeg,filename="plot.jpg");
dev.off ();
If you reach a clutter of too many plot windows in R, use graphics.off() to close all of the plot windows.
If you use ggplot2 the preferred way of saving is to use ggsave. First you have to plot, after creating the plot you call ggsave:
ggplot(...)
ggsave("plot.png")
The format of the image is determined by the extension you choose for the filename. Additional parameters can be passed to ggsave, notably width, height, and dpi.
Like this
png('filename.png')
# make plot
dev.off()
or this
# sometimes plots do better in vector graphics
svg('filename.svg')
# make plot
dev.off()
or this
pdf('filename.pdf')
# make plot
dev.off()
And probably others too. They're all listed together in the help pages.
For the first question, I find dev.print to be the best when working interactively. First, you set up your plot visually and when you are happy with what you see, you can ask R to save the current plot to disk
dev.print(pdf, file="filename.pdf");
You can replace pdf with other formats such as png.
This will copy the image exactly as you see it on screen. The problem with dev.copy is that the image is often different and doesn't remember the window size and aspect ratio - it forces the plot to be square by default.
For the second question, (as others have already answered), you must direct the output to disk before you execute your plotting commands
pdf('filename.pdf')
plot( yourdata )
points (some_more_data)
dev.off() # to complete the writing process and return output to your monitor
If you use R Studio http://rstudio.org/ there is a special menu to save you plot as any format you like and at any resolution you choose
If you open a device using png(), bmp(), pdf() etc. as suggested by Andrie (the best answer), the windows with plots will not pop up open, just *.png, *bmp or *.pdf files will be created. This is convenient in massive calculations, since R can handle only limited number of graphic windows.
However, if you want to see the plots and also have them saved, call savePlot(filename, type) after the plots are drawn and the window containing them is active.
plotpath<- file.path(path, "PLOT_name",paste("plot_",file,".png",sep=""))
png(filename=plotpath)
plot(x,y, main= file)
dev.off()
To add to these answers, if you have an R script containing calls that generate plots to screen (the native device), then these can all be saved to a pdf file (the default device for a non-interactive shell) "Rplots.pdf" (the default name) by redirecting the script into R from the terminal (assuming you are running linux or OS X), e.g.:
R < myscript.R --no-save
This could be converted to jpg/png as necessary
In some cases one wants to both save and print a base r plot. I spent a bit of time and came up with this utility function:
x = 1:10
basesave = function(expr, filename, print=T) {
#extension
exten = stringr::str_match(filename, "\\.(\\w+)$")[, 2]
switch(exten,
png = {
png(filename)
eval(expr, envir = parent.frame())
dev.off()
},
{stop("filetype not recognized")})
#print?
if (print) eval(expr, envir = parent.frame())
invisible(NULL)
}
#plots, but doesn't save
plot(x)
#saves, but doesn't plot
png("test.png")
plot(x)
dev.off()
#both
basesave(quote(plot(x)), "test.png")
#works with pipe too
quote(plot(x)) %>% basesave("test.png")
Note that one must use quote, otherwise the plot(x) call is run in the global environment and NULL gets passed to basesave().
dev.copy(png,'path/pngFile.png')
plot(YData ~ XData, data = mydata)
dev.off()