How to change colormap for plotting with arrows()?

Julia has an awesome documentation, including an example for arrows(). However I don’t figure, how to change the colormap that shows the strength of the arrows. I’d like to change it to :bluesreds. If you know how, let me know. :smiley:

There is a colormap attribute. The available colormaps are listed here:

I modified the script slightly to set the keyword attribute colormap = :bluesreds as below.

using GLMakie

f = Figure(size = (800, 800))
Axis(f[1, 1], backgroundcolor = "black")

xs = LinRange(0, 2pi, 20)
ys = LinRange(0, 3pi, 20)
us = [sin(x) * cos(y) for x in xs, y in ys]
vs = [-cos(x) * sin(y) for x in xs, y in ys]
strength = vec(sqrt.(us .^ 2 .+ vs .^ 2))

arrows!(xs, ys, us, vs, arrowsize = 10, lengthscale = 0.3,
    arrowcolor = strength, linecolor = strength, colormap = :bluesreds)


I got the following result.


Great, thank you! I have also tried that, but Visual Studio didn’t show me a picture (only if I remove the colormap attribute). Seems it was a bug. Now where I restarted it all works fine.

Note that within a REPL session, the last f is very critical. This implicitly invokes the equivalent of display(f), which causes the figure to show up.


For this reason I typically wrap my plotting functions in a begin end block that always ends with fig so no matter what I change the figure always comes out :slight_smile:

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