As a beginner on R I manage to produce correct relational graphs thanks to R. They are about correct in the visualization space but of very bad quality when I export them in PDF or in JPEG / PNG. The image is not centered, a part of the legend is missing, the graph is very small or blurred etc.
How do you proceed for the export?
Thanks in advance!
I am looking for the right handling or settings to export the graph visualizations produced in R?
I understood that I had to set up the viewer space but via the code but have no idea how to do it...
Here an example how to write a plot to a PNG file. The plot "commands" are embedded in png(....)and dev.off(). Several options are available to configure size and resolution.
png("myfile.png", width=1600, height=1200, res=300) # good for LaTeX or Word
#png("myfile.png", width=800, height=600, res=150) # good for Powerpoint or Impress
plot(iris$Sepal.Length, iris$Petal.Length)
dev.off()
Some hints:
width and height are given in pixels
res influences nominal resolution and font size (play with it)
use at least 300 dpi (dots per inch). For centimeters, the number of pixels = 300/2.54 * width in cm
professionals use 600 or even 1200 pixels per inch, but then .docx and .pptx files will dramatically increase
1600 x 1200px is good for 13.3 x 10 cm size in the printed document
If you work with LaTeX, it is in most cases better to use PDF for the figures. Another very good idea is to use Markdown for the text. Then, figures are automatically embedded.
I am using tableGrob in R to create a .png image of a formatted table, for inclusion in a MS Word report. For small tables this works, but for larger ones they do not fit in the image. I haven't been able to find any parameters that allow me to either force it to fit automatically, or to manually control the height and width of the image window.
I would be very grateful if somebody could show me how to do this.
I am using R version 3.3.1, via Rstudio version 1.0.136, on Linux Mint on a 64-bit PC. R packages used include gridExtra, gridGraphics, gtable and png.
The table (tabsave) is a simple data frame with 34 rows and six columns, the first being chr and all the others num.
Here is what the output looks like. You can see how the table extends beyond both the upper and lower borders of the image:
Here is the relevant code
gtab<-tableGrob(tabsave,rows=NULL,cols=nm,theme = ttheme_default(base_size=10)) # gtab is the graphical version of the table, for printing
png('test.png')
grid.draw(gtab)
dev.off()
Thank you for any help you can provide.
The solution is to give width and height parameters to the png function. They both default to 480, in the default unit of pixels (px).
So I just changed
png('test.png')
to
png('test.png',height=1200)
I played around with the width and height parameters until it gave the coverage I needed.
When the plotting is to the interactive plot device, rather than to a file (ie not using a function like png) it's just a matter of first resizing the plot window so it's big enough.
I plotted a map in R but when I export it the size is very small. How can I enlarge the map and still save it as a picture? (I know that I can save it as PDF and then it's a vector graphic - but I need to copy it to Power Point and also need a transparent background - I don't think that is possible with a PDF isn't it?)
As you can see here the map is way to small to use it in a Power Point slide:
If someone knows a good way to save it as vector graph that I can easily use in Power Point that would be perfect as well.
The png() function lets you specify width and height size in the default resolution of "px" and the defaults are 480 and 480. You can also supply a res argument in units of "ppi". If you have text you probably ought to specify point size >= 20 for legibility. I generally save my graphs as PDF and convert to PNG with an external program. However, the latest versions of PowerPoint will accept pdf formats. It is also possible to save as an .eps format.
First a caveat: I posted this question here on SuperUser, but it is clearly the wrong place to ask R questions. I recognize that it is not directly a programming question, but I believe it can be solved by changing how plots are produced (i.e. by coding appropriately). So I hope readers find this appropriate for the forum.
R plots usually consist entirely of vector graphics elements (i.e. points, lines, polygons, text). R permits you to save your figure (or copy-paste) in various formats including various raster formats, as a PDF, or as a Windows meta-file.
I usually save my images as PDFs and print them. This renders the images exactly as I intended them on paper, in the highest quality. I avoid raster formats (e.g. JPG, TIFF) for printing as inevitably the quality is poorer and publishers prefer vector formats.
However, I need to make a large multi-page desktop published document using Microsoft Word 2007, and therefore using PDFs is not an option. When I import my figures from meta-files, or copy and paste directly from R into Word both the screen and print rendering of the image changes slightly (e.g. polygons and their fills become slightly misaligned).
Given that I want to retain high vector quality (and not use raster formats), what can I do to make R vector graphics work with Word? (Of course Sweave and LaTeX would be nice, but again, not a realistic option).
Consider this example:
plot(c(1:100), c(1:100), pch=20)
## Copy and paste to Word 2007 as Windows metafile
## Print
## Quality is poorer (e.g. dot fills misaligned with borders)
pdf("printsPerfectly.pdf")
plot(c(1:100), c(1:100), pch=20)
dev.off()
## Now print PDF
## Quality is as expected
EDIT: Further to suggestions by #John I produced it as an EPS postscript file (see below), inserted it as a picture into Word. Because ultimately it will be printed from a PDF created from Word, I converted it to a PDF using default Word 2007 settings, printed it on my HP Laserjet P1606dn laser printer, and then took aphotograph to illustrate the issue of polygons borders and fills misaligning (image on left, below). I also produced it directly as PDF from R using pdf() and printed the PDF and took a photograph (image on right, below).
It may seem like small potatoes! But when you have gone to a lot of trouble to achieve high quality, it is disappointing to be thwarted at the end. In addition, it is not really obvious here, but the numerals are not as high-quality (left) as in the PDF (right), disregarding differences in focus on the photograph.
The accepted answer to me is not acceptable, since if one goes to the trouble of making a nice vector based figure, the last thing one would like to do is just rasterize it to a bitmap... Unless it's an increadibly complex graph that takes ages to render in vector format, or something like that, but for most graphs that's not the case.
The best solution is to export to Word directly in native Office vector format. I just made a new package, export, that allows one to do exactly that an allows export of either graphs or statistical tables to Word and Powerpoint, see
https://cran.r-project.org/web/packages/export/index.html and for demo see
https://github.com/tomwenseleers/export
For example:
library(devtools)
devtools::install_github("tomwenseleers/export")
library(export)
?graph2ppt
?graph2doc
?table2ppt
?table2doc
## export of ggplot2 plot
library(ggplot2)
qplot(Sepal.Length, Petal.Length, data = iris, color = Species,
size = Petal.Width, alpha = I(0.7))
# export to Word
graph2doc(file="ggplot2_plot.docx", width=7, height=5)
# export to Powerpoint
graph2ppt(file="ggplot2_plot.pptx", width=7, height=5)
You can also export to enhanced metafile using the function
graph2emf(file="ggplot2_plot.emf", width=7, height=5)
but the quality of the native Office format is better.
For final production you can also readily print it to PDF from Powerpoint if need be, and it will stay nicely in vector format then.
Your only option is to use high resolution raster graphics. Once you're over 300 dpi it will be completely indistinguishable from vector printed; it will just make larger files.. Your copy and paste method is coming in at 72 dpi and will look terrible. If you import from a file you can get the resolution in the file and things will be much better. Fortunately Office 2007 is supposed to handle png images, which have the best compression for typical graphs. Let's say you wanted the image 4" wide and 6" high...
png('printsGreat.png', width = 4, height = 6, units = 'in', res = 300)
plot(c(1:100), c(1:100), pch=20)
dev.off()
Also, Office 2007 is supposed to be able to handle EPS files and R postscript files are by default EPS compatible when you print one page.
postscript("printsPerfectly.eps", width = 4, height = 6, horizontal = FALSE, onefile = FALSE)
plot(c(1:100), c(1:100), pch=20)
dev.off()
But if you don't have luck with them go back to the high resolution image.
My preferred solution is to use the windows metafile device for plotting, e.g.:
win.metafile("mygraph.wmf")
print(gg1)
dev.off()
This produces a *.wmf file that can be copy-pasted into the word file.
The devEMF package seems to produce graphics that look nicer than the default wmf when pasted into PowerPoint.
Since I tried to produce png at high res in R and it didn't seem to work on my PC (if I set the resolution higher than, say, 300 dpi, R would produce an error like "cannot start png device"), the way I found was to save the figure using postscript() and then use GSView to convert the ps file into png with 600 dpi resolution. MS Word consumes the png's happily and the quality of print seems to be perfect.
What #Tom Wenseleers said:
The current best answer above to me is not acceptable, since if one
goes to the trouble of making a nice vector based figure, the last
thing one would like to do is just rasterize it to a bitmap... Unless
it's an increadibly complex graph that takes ages to render in vector
format, or something like that, but for most graphs that's not the
case.
For me, there is a new best answer to this question, since graph2ppt and graph2doc tend to move axis labels around (which apparently cannot be fixed; see here: https://github.com/davidgohel/rvg/blob/master/R/body_add_vg.R and here: export::graph2office moves axis labels around).
I think that .svg is the most appropriate vector format for usage with publication graphics. The only drawback is that older versions of e.g. MS Word cannot handle it. IN R, you could use the native graphics::svg - device. However, I'd recommend to use CairoSVG from the Cairo - Package, especially when you are working with non-native fonts (e.g. via the extrafont - package), because in contrast to graphics::svg, Cairo::CairoSVG embeds fonts quite nicely (without relying on GhostScript, if I am right).
If you are working with an older version of MS Word, you could use incscape (a free vector graphic editor) and convert your graph to .wmf, for example (which might be better than printing to .wmf directly, because R rasterizes points when exporting .wmf files).
An example:
## create plot
library (ggplot2)
library (extrafont)
# note: if you want to use other fonts than the standard ones - in this example "ChantillyLH" -
# you must register your fonts via
# font_import () ##run only once (type "y" in the console)
# and
# loadfonts (device = "win") ##run only once.
# Otherwise, the extrafont - package is not needed.
beautiful_plot <-
ggplot (data = iris, mapping = aes (x = Sepal.Length, y = Petal.Length)) +
geom_point () +
theme (text = element_text (size = 18,
family = "ChantillyLH")
)
# export SVG
library (Cairo)
CairoSVG ("My_Path/My_Plot.svg", width = 6, height = 6)
print (beautiful_plot)
dev.off ()
# the resulting SVG-file is in the the "My_Path" - Folder.
In Incscape, it looks like this:
Newer versions of Word can import raster graphics from SVG files. R 3.6.2 has built-in support for creating SVG files with the svg function - no extra packages needed.
Your example then becomes
svg("printsPerfectly.svg", width=4, height=4)
plot(c(1:100), c(1:100), pch=20)
dev.off()
Note that there is a known issue when you try to create PDF files from Word documents with embedded SVG files with thin lines. If you are using thin lines, e.g. with lwd=0.7 somewhere, you need to apply this workaround.
How do I export a re-sized version of the output I get from a call to GraphPlot
(or TreePlot if they produce different output) to a jpg file?
Currently, I'm simply calling Export[file_name, G]
where G is the result from a call to something like GraphPlot.
I'm using Microsoft office picture manager to view the jpgs,
but re-scaling them there yields unsatisfactory results due to poor resolution
(the graph I'm trying to plot has strings as labels which can't be made out after rescaling this way). I would like to be able to choose the size/resolution of the rendered jpg.
As Simon already pointed out, don't use a raster-format for a vector-graphics. Instead, export you plot to e.g. a scalable vector graphics:
graph = GraphPlot[ExampleData[{"Matrix", "HB/can_292"}, "Matrix"]];
Export["graph.svg", graph]
The advantage is, that in such an image, you can still adjust and change lines, polygons and colors. And finally, you can export it to an image of arbitrary quality easily.
And remember, for Plots which contain lines, polygons, ... everything with sharp edges you should never use jpg. General speaking, this is a format for photographs only since its compression is made for reducing filesize in natural images. In those images you don't recognize the compression, in images with text, lines and polygons you certainly will notice the artefacts. Use png if possible. Take your browser and zoom into the above image.
You can set both image size and compression level of the exported file by doing something like
Export[file_name, G, ImageSize -> 1200, "CompressionLevel" -> 0]
The best way I find is to use ImageResolution property. It Increases the resolution of exported image but does not change the scale. Use it like this:
Export[ "image-file-name.png", image, ImageResolution -> 500 ]
Set the size of your graph before exporting it:
Graph[theGraph, ImageSize->2000]