Is there a way to have an R Device (postscript would be great) write the output into a variable instead of a file?
For example I know this:
postscript(file="|cat")
plot(1:10)
dev.off()
Will send the postscript text to STDOUT. How can I get that text into a variable within R?
I've had success in getting the Binary of a plot into an R variable as a string. Its got some read/write overhead. In the snippet below, R saves the plot as a temp file and reads it back in.
## create a plot
x <- rnorm(100,0,1)
hist(x, col="light blue")
## save plot as temp file
png(filename="temp.png", width=500, height=500)
print(p)
dev.off()
## read temp file as a binary string
plot_binary <- paste(readBin("temp.png", what="raw", n=1e6), collapse="")
Maybe this is helpful to you.
postscript takes a command argument, hence postscript(file="",command="|cat")
Why on earth would you want to do that? R is not a very good system for manipulating Postscript files. If nothing else, you can use tempfile() to write the image to a file, which you can then read in using standard file functions. If you wanted to be fancy, you could perhaps use fifo() pipes, but I doubt it'll be much faster. But I suspect you'd be better off with a different approach.
You should be able to use a textConnection as follows.
tc <- textConnection("string", "w")
postscript(tc)
plot(1:10)
dev.off()
But string remains blank - maybe a bug?
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()
This is very elementary for those who use R... (But I do stats with Stata and Mplus.)
I develop many plots (638 in total) and want to save all in separate files. It worked well first, not now
for(i in 001:638){
## command for plot comes here, including mentioning of i ##
dev.copy(png,'plot-%d.png')
dev.off()
}
I want one file for each plot, but end up with a single plot file (plot_1.png), with only the last plot.
Christopher
png function will do this by default. For example, this will create 10 plots in your working directory.
png("plot-%d.png")
for(i in 1:10) plot(1:i)
dev.off()
You'll want to use one of the paste() functions to create your string.
Since you didn't provide a reproducible example I can only guess, but I think that something like this would probably work.
paste("plot",i,".png", sep = "")
in place of your current use of c style % replacement. So this
for(i in 001:638){
#command for plot comes here, including mentioning of i ##
dev.copy(png,paste("plot",i,".png", sep = ""))
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+)$")[, 2]
switch(exten,
png = {
png(filename)
eval(expr, envir = parent.frame())
dev.off()
},
{stop("filetype not recognized")})
#print?
if (print) eval(expr, envir = parent.frame())
invisible(NULL)
}
#plots, but doesn't save
plot(x)
#saves, but doesn't plot
png("test.png")
plot(x)
dev.off()
#both
basesave(quote(plot(x)), "test.png")
#works with pipe too
quote(plot(x)) %>% basesave("test.png")
Note that one must use quote, otherwise the plot(x) call is run in the global environment and NULL gets passed to basesave().
dev.copy(png,'path/pngFile.png')
plot(YData ~ XData, data = mydata)
dev.off()
I am still new to R and I have searched around for a solution to my simple question, but I haven't found an answer that I've been able to get to work. I am looking to use a previously identified variable per data set, here variable=SNPname to include in script for automated generation of graph output in png format.
I am using this to generate a kmeans plot and have:
(cl <- kmeans(FilteredData[,6:7], 5, nstart=25))
png("C:/temp/$SNPnamegraph1.png") #SNPname to include in filename
plot(FilteredData[,6:7], col=cl$cluster)
points(cl$centers, col=1:5, pch=8)
dev.off()
where I want to include that variable in line 2 at the beginning of the file name. Is there a simple way to do this that I am just missing?
Close, you're just missing the use of paste() and setwd()
setwd("C:/temp/") # use this to set where you want things saved
...
c1 <- kmeans...
png(paste(SNPname, " graph1.png", sep=""))
...
If it's in a loop of some kind, you might need to use SNPname[loop_var]