Auto-adjusting grid with CairoMakie heathmap

New to Julia
1

Hello,
I am generating a heatmap and I would like to highlight the cells. I managed to dot that with 5 cells per side (n=5):

using CairoMakie
using ColorSchemes
n=5
xs = 1:n
ys = 1:n
grid1 = rand(Float16, n, n)
grid2 = rand(Float16, n, n)
zs = grid1/grid2
fig, ax, hm = heatmap(xs, ys, zs;
    axis = (xlabel="X", ylabel="Y",
    xgridvisible = false, ygridvisible = false,
    #xgridcolor = :black, ygridcolor = :black,
    xminorgridcolor = :black,  yminorgridcolor = :black,
    xminorgridvisible = true, yminorgridvisible = true,
    xminorticks = IntervalsBetween(2), yminorticks = IntervalsBetween(2)),
    colormap = :bwr)
Colorbar(fig[:, end+1], hm)
colsize!(fig.layout, 1, Aspect(1, 1.0))
resize_to_layout!(fig)
translate!(hm, 0, 0, -100)

5
51314×1200 16.4 KB

But with other values, it does not work. For instance n=7 and n=10 give:
7
71342×1200 17.9 KB

10
101340×1200 20.2 KB

Is there a way to automatically fit a grid to the cells of the map? Cells are not the same as the axis…
Thank you

2

Ok you don’t need to coax the minor gridlines into doing that for you, you can explicitly plot your gridlines with vlines and hlines:

n = 10
xs = 1:n
ys = 1:n
grid1 = rand(Float16, n, n)
grid2 = rand(Float16, n, n)
zs = grid1/grid2
fig, ax, hm = heatmap(xs, ys, zs)
midpoints(x) = (x[1:end-1] .+ x[2:end]) .* 0.5
vlines!(midpoints(xs), color = :black, linewidth = 1)
hlines!(midpoints(ys), color = :black, linewidth = 1)
fig

grafik
grafik1028×772 17.8 KB

3

Thank you, but I get an error:

julia> zs = grid1/grid2
5×5 Matrix{Float16}:
 -2.938     13.28   -3.924   4.344   -1.856
  1.502    -12.05    4.812  -1.67     1.434
  1.107     -6.91    2.266  -0.221    0.5527
  0.11945   -7.035   2.916   0.6245   0.5527
 -0.4595     4.137  -1.104   0.6367  -0.3955

julia> fig, ax, hm = heatmap(xs, ys, zs;
           axis = (xlabel="X", ylabel="Y"),
           colormap = :bwr)

julia> Colorbar(fig[:, end+1], hm)
Colorbar()

julia> colsize!(fig.layout, 1, Aspect(1, 1.0))

julia> resize_to_layout!(fig)
(666.376f0, 600.0f0)

julia> # translate!(hm, 0, 0, -100)
       vlines!(midpoints(xs), color = :black, linewidth = 1)
ERROR: MethodError: no method matching vlines!(::StepRangeLen{Float64, Float64, Float64, Int64}; color=:black, linewidth=1)
Closest candidates are:
  vlines!(::Axis, ::Any; ymin, ymax, attrs...) at ~/.julia/packages/Makie/fEZv2/src/makielayout/helpers.jl:479
Stacktrace:
 [1] top-level scope
   @ none:1

julia> hlines!(midpoints(ys), color = :black, linewidth = 1)
ERROR: MethodError: no method matching hlines!(::StepRangeLen{Float64, Float64, Float64, Int64}; color=:black, linewidth=1)
Closest candidates are:
  hlines!(::Axis, ::Any; xmin, xmax, attrs...) at ~/.julia/packages/Makie/fEZv2/src/makielayout/helpers.jl:469
Stacktrace:
 [1] top-level scope
   @ none:1
4

You need to be on the latest Makie version, 0.17.4

5

I got:

julia> Pkg.status("CairoMakie")
      Status `~/.julia/environments/v1.7/Project.toml`
  [13f3f980] CairoMakie v0.7.5

How can I upgrade (if needed)?

6

CairoMakie has a different version than Makie, but for both ]up should be enough unless you have something else in your environment that blocks the newer versions.