Creating a smooth phase diagram

I'm looking to create a smooth phase diagram of different states (something similar to the bottom image below). My raw data is shown on the top left.

The issue is when I try to interpolate things, to smooth out the steps in the image, I always end up with some kind of border between the states. This is shown in the top right, for example, going down the dark red column, it transistions from dark red through light red to yellow. But the transition should be directly to yellow.

The issue causing this is that I have 6 different states I want to include in the phase diagram, but they don't all happen sequencially (i.e. we can go from state 1 to 3 without going though 2).

Is there a way to create smooth distinct regions of colour like the image at the bottom? (this image is just an example and does not correspond to my data)

[Benjamin Thompson]

So you can produce images like the one in the middle, but you want images like the first one, on the left? How is your third image related to this?

[John Fullerton]

Sorry, I didn't realise that the images had moved around after I posted it!

My raw data is the first image, the second one is to show the problem, and the third is a general example of what I'm trying to do but isn't the same data.

[Star Strider]

I have no idea what you’re doing or what the data are, however interpolating to a finer grid could be the solution. The edge colour problem is separate, and llikely could be solved by toggling the 'EdgeColor' property of whatever that plot is.

[John Fullerton]

I'm sorry, I haven't explained my issue well.

I'm creating a colormap with six different pixel values to represent the different states of my system that appear when varying X and Y coordinates. But interpolation means that to get from state 1 to 6, the map has to go through every other color.

But this isn't what I want to plot. Is there a way to interpolate different regions, where any color in my map can blend into any other color without going through any other states.

Thank you for your comment, I hope this makes more sense.

Answer 1

[Star Strider]

Again just guessing here, since I have no idea what you¹re actually doing.

I would still interpolate to a finer grid, and then threshold the results so that instead of a continuous gradient, the plot becomes stepwise.

Also, in this instance, the contourf function could be appropriate. It is possible to define the contour levels so only specific contours are plotted. This would eliminate the continuous gradient problem, and still produce the contours on a finer grid. It is also possible to turn off the contour lines themselves if it isn’t desirable to have them shown.

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[John Fullerton]

Thank you for your help, I'll try contourf.

[Star Strider]

My pleasure!