How to increase resolution of ggplots when exporting using officer R

Question

I want to export charts to a PPT and am using the officer package to achieve the same. However, the default resolution of the charts is low and I would like to change that. I am currently using the following call

    ph_with_gg(p1,type = "chart",res = 1200)

where p1 is a ggplot object. On running this, I get the following error:

    Error in png(filename = file, width = width, height = height, units = 
"in",  : 
  formal argument "res" matched by multiple actual arguments

Would really appreciate the help around this

score 11 · Accepted Answer · edited Nov 25 '19 at 13:17

Rather than using png, for high-resolution plots in PPT you should be using vector graphics.

See under extensions:

Vector graphics with package rvg

The package rvg brings an API to produce nice vector graphics that can be embedded in PowerPoint documents or Excel workbooks with officer.

This package provides functions dml() and ph_with() corresponding method to export ggplots to .pptx as vector graphics.

Example:

library(ggplot2)
library(officer)
library(rvg)
library(magrittr)
data(iris)

read_pptx() %>%
  add_slide(layout='Title and Content',master='Office Theme') %>%
  ph_with('Iris Sepal Dimensions', location = ph_location_type(type="title")) %>%
  ph_with(dml( ggobj=
                 ggplot(iris, aes(x=Sepal.Length,y=Sepal.Width,col=Species)) +
                 geom_point()), location = ph_location_type(type="body")) %>%
  print('iris_presentation.pptx')

As an additional benefit, you will be able to edit the charts in PowerPoint. For example, if you decided to capitalize the names of the 3 species, you could just edit the chart instead of editing the data and regenerating the slides. (You can also make the plots non-editable, but editable is the default.)

Thanks for pointing to this package. It has a function called ph_with_vg which solves the problem. Thanks a lot — Nishant Kachawa, Mar 12 '18 at 22:37

score 1 · Answer 2 · answered Mar 12 '18 at 18:22

1

Is it important that the plot is saved to a presentation in the code?

Otherwise using:

ggsave(filename = file, p1, width = width, height = height, dpi = dpi)

will give you a png of any resolution you need..

(provided that filename ends with .png and you set width, height and dpi to appropriate values)

answered Mar 12 '18 at 18:22

frostell

669
4
11

Hi. How do you know what value is appropriate to set the dpi? – Jules_ps Aug 17 '20 at 22:00

How to increase resolution of ggplots when exporting using officer R

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