pmacdasci / pmacplot

R package that helps create and export ggplot2 charts in the style used by the BBC News data team

PMACPLOT

This repo contains the functions of the pmacplot package, which once installed locally, provides helpful functions for creating and exporting graphics made in the style used by Peter Mac researchers (well that’s the aim, it’s just beginning Nov 2020). It is based on the BBC news bbplot package. This website also highlights plots researchers at Peter Mac have created and shows the code for the plots.

We need your help!

Would it be good if there was a uniform petermac ‘style’ that people could use if they want?
We could use the bbc style as a guide to discuss what aspects to use.
Please let us know what you think and/or what plotting resources you find useful Google doc
We would also love it if you have any example plots with code that we could highlight here.

Example plots

The figure below shows examples of plots created using the BBC news package (that this package is based on). We’ll replace with examples using this package when we have some. We’ve started adding some example plots from Peter Mac researchers for inspiration. You can find them under Articles or in the menu at the top of this page and reproduce them with the code shown.

Installing pmacplot

pmacplot is not on CRAN, so you will have to install it directly from Github using remotes.

If you do not have the remotes package installed, you will have to run the first line in the code below as well.

# install.packages('remotes')
remotes::install_github('PMacDaSci/pmacplot')

Using the functions

The package has two functions for plots: petermac_style() and finalise_plot().

Detailed examples on how to use the functions included within the pmacplot package to produce graphics will be included at this website. Examples for the BBC News versions can be found in the R cookbook, as well as a more general reference manual for working with ggplot2.

A basic explanation and summary here:

petermac_style()

1. petermac_style(): has no arguments and is added to the ggplot chain after you have created a plot. What it does is generally makes text size, font and colour, axis lines, axis text and many other standard chart components into Peter Mac style.

The function is pretty basic and does not change or adapt based on the type of chart you are making, so in some cases you will need to make additional theme arguments in your ggplot chain if you want to make any additions or changes to the style, for example to add or remove gridlines etc. Also note that colours for lines in the case of a line chart or bars for a bar chart, do not come out of the box from the petermac_style function, but need to be explicitly set in your other standard ggplot chart functions.

Example of how it is used in a standard workflow:

line <- ggplot(line_df, aes(x = year, y = lifeExp)) +
geom_line(colour = "#007f7f", size = 1) +
geom_hline(yintercept = 0, size = 1, colour="#333333") +
petermac_style()

finalise_plot

1. finalise_plot: will save out your plot with the correct guidelines for publication for a Peter Mac graphic. It is made up of functions that will left align your title, subtitle and source and save it to your specified location. The function has six arguments, three of which need to be explicitly set and three that are defaults unless you overwrite them.

Here are the function arguments: finalise_plot(plot_name, source_name, save_filepath, width_pixels, height_pixels)

• plot_name: the variable name that you have called your plot, for example for the chart example above plot_name would be "line"
• source_name: the source text that you want to appear at the bottom left corner of your plot. You will need to type the word "Source:" before it, just the source, so for example source = "Source: ONS" would be the right way to do that.
• save_filepath: the precise filepath that you want your graphic to save to, including the .png extension at the end. This does depend on your working directory and if you are in a specific R project. An example of a relative filepath would be: /charts/line_chart.png.
• width_pixels: this is set to 640px by default, so only call this argument and specify the width you want your chart to be.
• height_pixels: this is set to 450px by default, so only call this argument and specify the height you want your chart to be.

Example of how the finalise_plot() is used in a standard workflow. This function is called once you have created and finalised your chart data, titles and added the petermac_style() to it (see above):

finalise_plot(plot_name = my_line_plot,
source = "Source: ONS",
save_filepath = "filename_that_my_plot_should_be_saved_to-nc.png",
width_pixels = 640,
height_pixels = 550)