Making a heat map from three vectors of different lengths

From a set of three vectors (x,y,z), I want to generate a heat map of x,y and z where the color bar would denote z-values.Perhaps this answer was relevant https://www.mathworks.com/matlabcentral/answers/105390-making-a-heat-map-from-three-vectorsBut it was erased from the database. Thanks!

[Adam Danz]

That answer was added in 2013 but matlab's heatmap came out in 2017. However, the bioinformatics Toolbox has a function HeatMap that has been available since 2009. My answer shows how to use the newer heatmap function. Note that you could also use imagesc to create a similar plot.

Answer 1

[Adam Danz]

In heatmap, XData define the number of columns and YData define the number of rows. Your matrix y is 21x10 meaning there will be 21 rows and 10 columns.

load('matlab.mat'); 
heatmap(z,x,y)

If you want there to be 10 rows and 21 columns,

figure
heatmap(x,z,y');  % note the transpose on y

How to remove cell labels

The examples above do not show the cell labels because the axes are too small given the number of cells but to remove the cell labels,

h = heatmap(__)

h.CellLabelColor = 'none';

Alternative: imagesc

Another option is to use imagesc but note

• The direction of the y-axis differs between heatmap and imagesc
• imagesc sorts the x and y values

Yet another alternative is to use histogram2.

figure()
imagesc(z,x,y)

% reproduce heatmap's colormap
n=256;
cmap = sky(n); % R2023a
% Prior to R2023a: cmap = [linspace(.9,0,n)', linspace(.9447,.447,n)', linspace(.9741,.741,n)'];
colormap(cmap); 
axis xy
colorbar()

[ct8]

Thanks Adam! Can I get rid of the numbers and boxes in the map to make it clean? I am seeing attached on my end.

[Adam Danz]

See updated answer.

[ct8]

Neat! Thanks a lot!