heatmap

📝Syntax

heatmap(C)
heatmap(xvalues, yvalues, C)
heatmap(tbl, xvar, yvar)
heatmap(tbl, xvar, yvar, 'ColorVariable', cvar)
heatmap(parent, ...)
heatmap(..., propertyName, propertyValue)
h = heatmap(...)

📥Input Arguments

Parameter	Description
C	Numeric matrix used as color data.
xvalues	Labels for matrix columns: cell string, string, character, or numeric vector.
yvalues	Labels for matrix rows: cell string, string, character, or numeric vector.
tbl	Source table used to calculate heatmap values.
xvar	Table variable used for x categories.
yvar	Table variable used for y categories.
cvar	Numeric table variable averaged for each x/y category pair.
parent	Axes or hggroup parent.
propertyName	Supported property name.
propertyValue	Property value.

📤Output Arguments

Parameter	Description
h	Heatmap chart object containing the heatmap image, grid, labels, and colorbar state.

📄Description

heatmap displays a numeric matrix as a scaled color image with row and column labels. For table input, categories are sorted and the color data is aggregated by category pair.

With heatmap(tbl, xvar, yvar), color data contains counts and ColorMethod is count. With ColorVariable, color data contains means and ColorMethod is mean.

This implementation returns a heatmap chart object. The chart UserData contains the fields ChartType, Image, Grid, CellLabels, Colorbar, XData, YData, ColorData, SourceTable, XVariable, YVariable, ColorVariable, ColorMethod, and Options.

Supported name/value properties are Title, XLabel, YLabel, SourceTable, XVariable, YVariable, ColorVariable, ColorMethod, XData, YData, XDisplayLabels, YDisplayLabels, ColorLimits, Colormap, ColorbarVisible, GridVisible, CellLabelFormat, CellLabelColor, MissingDataLabel, FontColor, FontSize, and Visible.

💡Examples

Display a numeric heatmap.

C = [1 2 3; 4 5 6];
heatmap(C);

Use row and column labels.

C = [3 7 2; 6 5 8];
heatmap({'A', 'B', 'C'}, {'Low', 'High'}, C, ...
  'Title', 'Scores', 'XLabel', 'Column', 'YLabel', 'Group');

Create a heatmap from table categories.

T = table({'B'; 'A'; 'B'}, {'Y'; 'X'; 'X'}, [2; 5; 8], ...
  'VariableNames', {'x', 'y', 'v'});
heatmap(T, 'x', 'y', 'ColorVariable', 'v');

Customize colors and labels.

C = peaks(12);
heatmap(C, 'ColorLimits', [-6 8], 'Colormap', turbo(64), ...
  'CellLabelFormat', '%0.1f', 'GridVisible', 'off');