R – Control point border thickness in ggplot

borderggplot2pointrthickness

When using ggplot, I can set shape to 21-25 to get shapes that have independent setting for the internal (fill) and border (col) colors, like so:

df <- data.frame(id=runif(12), x=1:12, y=runif(12))
ggplot(df, aes(x=x, y=y)) + 
  geom_point(aes(fill=id, size=id), colour="black", shape=21)

enter image description here

However, I can't figure out how to control the thickness of the shape borders, either setting them absolutely or as an aesthetic mapping. I note that if I set an lwd value, it overrides the size aesthetic:

ggplot(df, aes(x=x, y=y)) + 
  geom_point(aes(fill=id, size=id), colour="black", shape=21, lwd=2)

enter image description here

How do I control the border thickness?

Best Answer

Starting in version 2.0.0 of ggplot2, there is an argument to control point border thickness. From the NEWS.md file:

geom_point() gains a stroke aesthetic which controls the border width of shapes 21-25 (#1133, @SeySayux). size and stroke are additive so a point with size = 5 and stroke = 5 will have a diameter of 10mm. (#1142)

Thus, the correct solution to this is now:

df <- data.frame(id=runif(12), x=1:12, y=runif(12))
ggplot(df, aes(x=x, y=y)) + 
  geom_point(aes(fill=id, size=id), colour="black", shape=21, stroke = 2)

Related Solutions

Css – Should I use ‘border: none’ or ‘border: 0’

Both are valid. It's your choice.

I prefer border:0 because it's shorter; I find that easier to read. You may find none more legible. We live in a world of very capable CSS post-processors so I'd recommend you use whatever you prefer and then run it through a "compressor". There's no holy war worth fighting here but Webpack→LESS→PostCSS→PurgeCSS is a good 2020 stack.

That all said, if you're hand-writing all your production CSS, I maintain —despite the grumbling in the comments— it does not hurt to be bandwidth conscious. Using border:0 will save an infinitesimal amount of bandwidth on its own, but if you make every byte count, you will make your website faster.

The CSS2 specs are here. These are extended in CSS3 but not in any way relevant to this.

'border'
    Value:      [ <border-width> || <border-style> || <'border-top-color'> ] | inherit
    Initial:    see individual properties
    Applies to:     all elements
    Inherited:      no
    Percentages:    N/A
    Media:      visual
    Computed value:     see individual properties

You can use any combination of width, style and colour.
Here, 0 sets the width, none the style. They have the same rendering result: nothing is shown.

R – Fill and border colour in geom_point (scale_colour_manual) in ggplot

You'll have to use shapes from 21 to 25. These are the ones that have colour and fill properties:

ggplot(df, aes(own, method)) + 
     geom_point(colour="white", shape=21, size = 4, 
     aes(fill = factor(label))) + 
     scale_fill_manual(values=c("blue", "cyan4"))

If you want different colours for colour as well, then:

ggplot(df, aes(own, method)) + 
      geom_point(aes(colour=factor(label), 
      fill = factor(label)), shape=21, size = 4) + 
      scale_fill_manual(values=c("blue", "cyan4")) + 
      scale_colour_manual(values=c("white", "black"))