Missing colorschemes in heatmap plot

[juliohm]

I couldn't find an example in the docs nor an issue mentioning this function, how can we get access to imshow() from PyPlot to visualize large 2D matrices?

[tbreloff]

heatmap? If they are really large you shouldn't use pyplot.

On Wednesday, October 19, 2016, Júlio Hoffimann Mendes < notifications@github.com> wrote:

Hi,

I couldn't find an example in the docs nor an issue mentioning this function, how can we get access to imshow() from PyPlot to visualize large 2D matrices?

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[juliohm]

@tbreloff I am actually talking about matrices that represent images. They have 400x400 pixels for example.

[tbreloff]

What is the precise type that you want to display? (show me the output of typeof(mat))

[juliohm]

The type is Array{Float64,2}, nothing fancy.

[tbreloff]

so then: heatmap(mat, yflip=true)

[juliohm]

I don't know why it didn't work before! I was probably doing something wrong somewhere else in the code. Closing the issue :+1:

[juliohm]

How to change the colormap? I tried passing the option cmap, colormap, cm, none worked.

Where in the source I can find information on these keyword arguments that are valid across functions?

[tbreloff]

fillcolor or fc, or also seriescolor, color, c should do it. See the attributes page of the docs

[juliohm]

I tried color=:jet but it didn't work. Where I can find a list of all these symbols?

[tbreloff]

julia> PlotUtils._gradients |> keys |> showall
Symbol[:phase,:lightrainbow,:ice,:curl,:matter,:speed,:turbid,:sand_grad,:tempo,:solarized_light_grad,:gray,:reds,:blues,:redsblues,:darkrainbow,:viridis,:algae,:greens,:balance,:solar,:solarized_grad,:dark_grad,:haline,:oxy,:plasma,:deep,:heat,:magma,:inferno,:rainbow,:orange_grad,:bluesreds,:amp,:dense,:darktest,:lime_grad,:grays,:thermal,:delta,:lighttest]

[juliohm]

Thanks! So, the standard jet is not available currently?

[tbreloff]

jet kinda sucks... you should try something else :)

[juliohm]

Well, jet is kind of very famous, no harm in include it to the list :)

[KristofferC]

It is harmful since it is so bad.

[juliohm]

Why is it so bad? Do you have links?

[tbreloff]

https://github.com/matplotlib/matplotlib/issues/875

[juliohm]

My eyes are not that sensitive, but if experts are saying jet is harmful, I accept it.

[juliohm]

I tried the :ice color listed above and it is also not recognized. Could you please update the docs and the code to translate the supported colorschemes? Many users like myself will open issues about it.

[juliohm]

Could you please help on this issue? I am gradually moving to Plots.jl, but there are still some corners I need to round for my day-to-day usage.

[tbreloff]

I'm sorry... I don't see anything actionable (besides a request for more docs?) What do you need help with? The gitter channel is good for getting help when learning (as opposed to reporting a bug in the issues).

[juliohm]

Hi Tom, the :ice color scheme is not working for me even though it is listed above. I will double check again today the script to see if it was something else.

[tbreloff]

This works for me: using Plots; heatmap(rand(100,100),c=:ice)

You might need to check out Plots/PlotUtils. I'll tag a new version in a couple months

[juliohm]

Hi Tom, the :ice color scheme is not working for me even though it is listed above.

-Júlio

[tbreloff]

Pkg.checkout("Plots"); Pkg.checkout("PlotUtils") should work for you.

[ttparker]

@tbreloff your command PlotUtils._gradients |> keys |> showall didn't work for me. I might be worth adding the list of gradient schemes to the documentation.

[juliohm]

See https://discourse.julialang.org/t/current-list-of-colorschemes-in-plots-jl/5420

[mkborregaard]

You could also actually check the documentation: http://docs.juliaplots.org/latest/colors/ :joy:

[ttparker]

@mkborregaard I did - by searching for several of the color scheme names using the documentation's built-in search function. This got no results, because the names are listed in an image file :-)

[mkborregaard]

I see, good point. It would be nice with a revision of that page that changed the display of each gradient to a narrow rectangle with a markdown title.