MATLAB: How to plot a 3D Histogram with one axis of categorical data

hist3MATLAB

Hi I'm trying to create a 3D histogram using hist3 and would like the following axes:

x-axis: categorical data eg. the type of modification to the set-up
y-axis: output data eg. time
z-axis: frequency.

I understand how to get the y and z axis conditions, but I am unsure of how to get categorical data on one of the axes in a 3d plot.

Best Answer

Hi Aseer,

For the hist3 function the user should need a 2D Matrix in which 1st column is x value, and 2nd column is y value. Then the function plots number of occurrences of the pairs x, y as the z parameter.

The 2D matrix has to be numeric in data in this function, for this you have to convert categories into numeric data.

https://www.mathworks.com/matlabcentral/answers/264383-convert-categorical-to-numeric

Related Solutions

MATLAB: Convert categorical to numeric

https://www.mathworks.com/matlabcentral/answers/394456-how-to-convert-from-categorical-to-double

https://www.mathworks.com/matlabcentral/answers/264383-convert-categorical-to-numeric#answer_311566

MATLAB: “binning” data with 2D coordinates

[ux, ~, xidx] = unique(data(1,:));
[uy, ~, yidx] = unique(data(2,:));
%count the number of points at each unique x/y combination
counts = accumarray([xidx(:), yidx(:)], 1);  
%average the z that fall into each unique x/y combination
avgs = accumarray([xidx(:), yidx(:)], data(3,:).');
%create a list of the z that fall into each unique x/y combination
zs = accumarray([xidx(:), yidx(:)], data(3,:).', [], @(V) {V}, {});

But perhaps what you want is instead a 2D histogram:

https://www.mathworks.com/help/matlab/ref/histogram2.html

or if you have an older version:

https://www.mathworks.com/videos/making-a-2d-or-3d-histogram-to-visualize-data-density-97260.html

https://www.mathworks.com/matlabcentral/fileexchange/45325-efficient-2d-histogram--no-toolboxes-needed

Best Answer

Related Solutions

MATLAB: Convert categorical to numeric

MATLAB: “binning” data with 2D coordinates

Related Question