hello, i was trying to learn a bit of julia by doing some plotting although i have encountered some issues while using color palettes:
scatter(df.x, df.y, palette = :tab20b,
xlabel = :x, ylabel = :y)
i have tried several backends and found that color keyword for palette application could be used although with no succes: all plotted points are of one color
what could i do with that?
thanks
There’s a slight misunderstanding here of how colours are applied in calls to scatter: every call to scatter creates a group of points which all have the same colour, by default the first colour of whatever colour palette you are specifying.
If you then call scatter! again (note the !, which indicates that the existing plot is modified), the next colour of your chosen colour palette is applied to the next group of points. Consider:
julia> using Plots
julia> scatter(ones(10), rand(10), palette = :tab20b)
julia> scatter!(1 .+ ones(10), rand(10), palette = :tab20b)
julia> scatter!(2 .+ ones(10), rand(10), palette = :tab20b)
julia> scatter!(3 .+ ones(10), rand(10), palette = :tab20b)
julia> scatter!(4 .+ ones(10), rand(10), palette = :tab20b)
julia> scatter!(5 .+ ones(10), rand(10), palette = :tab20b)
which creates:
If you want different colours within one series, you need to specify a vector of colours of the same length as the number of points you’re looking to plot:
julia> scatter(1:10, 1:10, palette = :tab20b, color = 1:10)
hi, thank you for very detailed explanation!
i went further and tried using another vector to color the points by value - is there way to supply palette to do it in Plots.jl ?
i have found a way to simply supply the vector in VegaLite and ggplot although would be nice to stick to one package for plotting