Pgfplotsx, plots: non-uniform colormaps only partially implemented

AntoninDellaNoce · October 1, 2020, 10:39pm

Hi,
I have an error at the level of pgfplots package when using pgfplotsx() backend to draw surfaces. Here is the working example provided by the Plots documentation

surface(range(-3,3, length=30), range(-3,3, length=30),
               (x, y)->exp(-x^2-y^2),
               label="",
               colormap_name = "viridis",
               extra_kwargs =:subplot)

returns

! Package pgfplots Error: Sorry, non-uniform colormaps are only partially imple
mented, yet: the provided points must be multiples of the mesh width h=0.11157p
t (but I found one with H/h = 0.11201pt/0.11157pt = 1+-0.004 which is no intege
r). Perhaps it helps to provide the mesh widths as argument as in {<name>}{[1cm
] <color arguments>}? The error occured near `rgb(0.50196078cm)=(0.73568300,0.2
1590600,0.33024500)'.

However, other types of 3d plot are working, like for instance (also from Plots doc)

n = 100
ts = range(0, stop = 8π, length = n)
x = ts .* map(cos, ts)
y = (0.1ts) .* map(sin, ts)
z = 1:n
plot(x, y, z, zcolor = reverse(z), m = (10, 0.8, :blues, Plots.stroke(0)), leg = false, cbar = true, w = 5)
plot!(zeros(n), zeros(n), 1:n, w = 10)

Now you may need me to give you a bit of context:
I have just upgraded Julia from 1.1.1 to 1.5.2. On the previous version 1.1.1, I had a segmentation fault for any kind of plots, and in the log, there was something like

_update_subplot_colors at /home/antonin/.julia/packages/Plots/cc8wh/src/args.jl:1446
_update_subplot_args at /home/antonin/.julia/packages/Plots/cc8wh/src/args.jl:1533
unknown function (ip: 0x7f4b833a94cb)
jl_fptr_trampoline at /buildworker/worker/package_linux64/build/src/gf.c:1842
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2197
_subplot_setup at /home/antonin/.julia/packages/Plots/cc8wh/src/pipeline.jl:299
_plot! at /home/antonin/.julia/packages/Plots/cc8wh/src/plot.jl:206

After the upgrading, everything is working just fine except the surface with pgfplotsx backend. I can draw surfaces with other backends. That may be a completely different problem, but that was the beginning of my troubles with pgfplotsx, that was working great before a global package update in Julia 1.1.1.
Thanks a lot for your help

BeastyBlacksmith · October 2, 2020, 10:34am

AntoninDellaNoce:

surface(range(-3,3, length=30), range(-3,3, length=30),
               (x, y)->exp(-x^2-y^2),
               label="",
               colormap_name = "viridis",
               extra_kwargs =:subplot)

What version of Plots.jl are you on? That example works for me on Plots v.1.6.7

AntoninDellaNoce · October 2, 2020, 10:38am

Same version as me. The problem seems related to my installation of pgfplots, maybe a missing dependency ?

BeastyBlacksmith · October 2, 2020, 10:40am

You could try updating your latex-packages

AntoninDellaNoce · October 2, 2020, 10:49am

Thanks for this remark, this is clearly an option to consider. I am just afraid to do it by superstition (all my previous troubles have emerged after package update in Julia or latex), so I may postpone it after submitting the manuscript I am writing.

Tamas_Papp · October 2, 2020, 11:00am

Assuming you are using version control (if you aren’t, you should, eg git), you can always just roll back to a previous state if you commit the relevant Manifest.toml.

BeastyBlacksmith · October 2, 2020, 11:01am

For reference: my pgfplots version is 1.17 (you can check that via texdoc pgfplots)

AntoninDellaNoce · October 2, 2020, 12:16pm

Indeed, my version is 1.13. As my TeX Live manager was frozen, I am reinstalling all \LaTeX anyway . Thanks @Tamas_Papp for letting me know about Manifest.toml. I did not use it.
Plotting surface should normally work after this update.

AntoninDellaNoce · October 2, 2020, 1:04pm

No , I still have the same error after updating pgfplots to 1.17 (in fact after having updated all latex packages).

BeastyBlacksmith · October 2, 2020, 1:13pm

Too bad, can you save that plot as .tex via savefig and paste the file here?

AntoninDellaNoce · October 2, 2020, 1:25pm

Here is the .tex generated by the surface command, but only with a four points grid.

\begin{tikzpicture}[/tikz/background rectangle/.style={fill={rgb,1:red,1.0;green,1.0;blue,1.0}, draw opacity={1.0}}, show background rectangle]
\begin{axis}[point meta max={1.522997974471263e-8}, point meta min={1.522997974471263e-8}, legend cell align={left}, title={}, title style={at={{(0.5,1)}}, anchor={south}, font={{\fontsize{14 pt}{18.2 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, legend style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, line width={1}, solid, fill={rgb,1:red,1.0;green,1.0;blue,1.0}, fill opacity={1.0}, text opacity={1.0}, font={{\fontsize{8 pt}{10.4 pt}\selectfont}}, at={(1.02, 1)}, anchor={north west}}, axis background/.style={fill={rgb,1:red,1.0;green,1.0;blue,1.0}, opacity={1.0}}, anchor={north west}, xshift={1.0mm}, yshift={-1.0mm}, width={145.4mm}, height={99.6mm}, scaled x ticks={false}, xlabel={}, x tick style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, opacity={1.0}}, x tick label style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, opacity={1.0}, rotate={0}}, xlabel style={at={(ticklabel cs:0.5)}, anchor=near ticklabel, font={{\fontsize{11 pt}{14.3 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, xmajorgrids={true}, xmin={-3.0}, xmax={3.0}, xtick={{-3.0,-2.0,-1.0,0.0,1.0,2.0,3.0}}, xticklabels={{$-3$,$-2$,$-1$,$0$,$1$,$2$,$3$}}, xtick align={inside}, xticklabel style={font={{\fontsize{8 pt}{10.4 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, x grid style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={0.1}, line width={0.5}, solid}, axis x line*={left}, x axis line style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, line width={1}, solid}, scaled y ticks={false}, ylabel={}, y tick style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, opacity={1.0}}, y tick label style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, opacity={1.0}, rotate={0}}, ylabel style={at={(ticklabel cs:0.5)}, anchor=near ticklabel, font={{\fontsize{11 pt}{14.3 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, ymajorgrids={true}, ymin={-3.0}, ymax={3.0}, ytick={{-3.0,-2.0,-1.0,0.0,1.0,2.0,3.0}}, yticklabels={{$-3$,$-2$,$-1$,$0$,$1$,$2$,$3$}}, ytick align={inside}, yticklabel style={font={{\fontsize{8 pt}{10.4 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, y grid style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={0.1}, line width={0.5}, solid}, axis y line*={left}, y axis line style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, line width={1}, solid}, scaled z ticks={false}, zlabel={}, z tick style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, opacity={1.0}}, z tick label style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, opacity={1.0}, rotate={0}}, zlabel style={, font={{\fontsize{11 pt}{14.3 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, zmajorgrids={true}, zmin={1.522997974471263e-8}, zmax={1.0000000152299797}, ztick={{0.2,0.4,0.6000000000000001,0.8,1.0}}, zticklabels={{$0.2$,$0.4$,$0.6$,$0.8$,$1.0$}}, ztick align={inside}, zticklabel style={font={{\fontsize{8 pt}{10.4 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, z grid style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={0.1}, line width={0.5}, solid}, axis z line*={left}, z axis line style={color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, line width={1}, solid}, colormap name={plots1}, colorbar, colorbar style={title={}, xticklabel style={font={{\fontsize{8 pt}{10.4 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}, yticklabel style={font={{\fontsize{8 pt}{10.4 pt}\selectfont}}, color={rgb,1:red,0.0;green,0.0;blue,0.0}, draw opacity={1.0}, rotate={0.0}}}, view={30}{30}, colormap name={viridis}]
    \addplot3[color={rgb,1:red,0.7328;green,0.2143;blue,0.3321}, name path={26a91c05-db1a-49db-a4e4-c44d5946a574}, surf, mesh/rows={2}, mesh/cols={2}, z buffer={sort}, forget plot]
        table[row sep={\\}]
        {
            \\
            -3.0  -3.0  1.522997974471263e-8  \\
            3.0  -3.0  1.522997974471263e-8  \\
            -3.0  3.0  1.522997974471263e-8  \\
            3.0  3.0  1.522997974471263e-8  \\
        }
        ;
\end{axis}
\end{tikzpicture}

BeastyBlacksmith · October 2, 2020, 1:29pm

Okay, my fault , can you use the following plot

surface(range(-3,3, length=30), range(-3,3, length=30),
               (x, y)->exp(-x^2-y^2),
               label="",
               colormap_name = "viridis",
               extra_kwargs =:subplot,
               tex_output_standalone = true
)

AntoninDellaNoce · October 2, 2020, 1:48pm

The surface is properly generated when I compile the standalone file with pdflatex. The file has too many lines even with a 2 points grid. But I guess that we both have the exact same file generated. My problem may be located at the level of lualatex compiler.

AntoninDellaNoce · October 2, 2020, 1:56pm

Many thanks for this alternative solution by the way. I can generate the surface by pdflatex at least.

AntoninDellaNoce · October 2, 2020, 2:01pm

Sorry for not being clear, the error is still there when I compile with pdflatex but the graph appears without problem with

 pdflatex \\nonstopmode\\input plot.tex

I do not see any visual impact that may be caused by this error, when I force it to be ignored by the compiler.

AntoninDellaNoce · October 2, 2020, 2:16pm

Here is the output after the compilation with error ignored. Personally, I don’t see where this “non-uniform colormaps” may act.