heatmap function doesn't work (Error in heatmap (line 138))

I'm trying to use the heatmap function. I can't get it to work. I can't even get the example from the mathworks website to work:

cdata = [45 60 32; 43 54 76; 32 94 68; 23 95 58];

h = heatmap(cdata);

which returns:

Not enough input arguments.

(Error in heatmap (line 138)

[h3, Centers] = hist3([x1, x2], nbins) ;

I don't know how I can figure out what's wrong with my code, if the example doesn't even work. Any help would be appreciated.

[Adam Danz]

Let's check that you don't have more than 1 heatmap file. Could you return the results of this line below? It should produce one or more paths to heatmap files.

which heatmap -all

[bryan flood]

I think you're onto something. It returns 4 options (see below - I've removed some of the directory path that doesn't seem relevant). One looks like a file I downloaded from the file exchange, 2 in the MATLAB folder and 1 in the toolboxes folder, which is likely a third party tool box I downloaded (I've been trying all sorts of things to get a usable heatmap function).

I assume I should remove all but one? Of the two in the MATLAB directory, how do I know which one to remove?

D:\...\heatmap.m

C:\Program Files\MATLAB\R2019a\toolbox\matlab\bigdata\@tall\heatmap.m % tall method

C:\Program Files\MATLAB\R2019a\toolbox\matlab\specgraph\heatmap.m % Shadowed

C:\Users\...\Roaming\MathWorks\MATLAB Add-Ons\Toolboxes\Customizable Heat Maps\heatmap.m % Shadowed

[bryan flood]

I got rid of the the two that weren't in the MATLAB file (C:\Program Files\MATLAB\R2019a\toolbox\matlab\...) and it seems to be working now.

Is there supposed to be 2 heatmap functions (one is labelled as 'tall method', the other 'shadowed')? Should I be removing one, or leaving them?

Thanks for the help

[Star Strider]

Leave the ones that are subdirectories of: C:\Program Files\MATLAB\R2019a\toolbox\matlab\.

I would just slightly rename the one you downloaded from the File Exchange, so that it doesn’t overshadow the built-in MATLAB functions. Removimg it completely is unnecessary. It may have features you want.

[Steven Lord]

Leave them both.

The one in the @tall directory is the heatmap method used when you try to create a heatmap plot with a tall array as input.

The one in the specgraph directory is the heatmap function used when you try to create a heatmap plot with normal double precision or table data.

Answer 1

[Adam Danz]

The problem was caused by a file named heatmap.m that overshadowed Matlab's built-in function of the same name. This was discovered after listing all files on path that had the name heatmap.

which heatmap -all

In r2019a (and presumably other recent releases) two files are listed that are associated with Matlab's heatmap() function.

C:\Program Files\MATLAB\R2019a\toolbox\matlab\specgraph\heatmap.m
C:\Program Files\MATLAB\R2019a\toolbox\matlab\bigdata\@tall\heatmap.m  % tall method

The second one is used with tall arrays.