Custom heat maps- How to highlight a specific value in the heatmap

I have a cell array of 6 cells (Mycell)

Each cell (i)containing 1486X492 points- each point is a value betwen 1 and -1 in decimal points.

I would like to plot this in a heatmap highligting only the points that are between 0.01 to -0.01

h = heatmap (Mycell{i});

I am not sure how to apply colour limits or any other better way to do this

Thanks

[Mathieu NOE]

see

Threshold to set colour for different scale range in Heatmap - File Exchange - MATLAB Central (mathworks.com)

Heatmap with specified color ranges? - MATLAB Answers - MATLAB Central (mathworks.com)

[Mel A]

Thank you @Mathieu NOE.

[Mathieu NOE]

My pleasure !

Answer 1

[Voss]

Maybe one of the following two approaches will be useful, depending on exactly what you want to see.

First, make up some data:

% some made-up data:
data = rand(25)*2-1;                  % uniform random on (-1,1)
data(randi(numel(data),[1 250])) = 0; % put some extra zeros in there

Approach 1: Use a custom colormap:

% this colormap will span values from -1 to 1
cmap = parula(200);
% make the range from -0.01 to 0.01 (i.e., the middle two rows)
% white in color, for highlighting:
cmap([100 101],:) = 1;

% create the heatmap
h = heatmap(data,'GridVisible',false);
% apply the colormap
colormap(cmap)
% apply the color limits (full range of the data)
clim([-1 1])

Approach 2: Use a standard colormap, but set the color limits to [-0.01 0.01]:

% some standard built-in colormap:
cmap = parula();

% create the heatmap
h = heatmap(data,'GridVisible',false);
% apply the colormap
colormap(cmap)
% apply the color limits (within the narrow range only 
% - data outside this range map to the first or last color)
clim([-0.01 0.01])