How to insert a line over a heatmap using code?

How can I insert a line over a heatmap in my code? I would rather not use the figure tools manually because I have to do multiple lines.

Answer 1

[Robert U]

Hi Samantha Clayton:

Since I do not know your code I can only demonstrate in the following example how to draw a vertical and a horizontal line into a contourf-plot (assuming you mean something like that).

 Z = peaks(20);

 ah = axes;
 h = contourf(Z,10,'Parent',ah);
 hold(ah,'on')

 plot(ah,[0 25],[10 10],'white') % horizontal line
 plot(ah,[10 10],[0 25],'white') % vertical line

 ah.XLim = [2 20];
 ah.YLim = [2 20];

There is a HeatMap-Command in Bioinformatics toolbox, so I do not know whether same strategy is working for that.

Kind regards,

Robert

[Walter Roberson]

New MATLAB also have heatmap().

[Osama El-Ghonimy]

Not working with Heatmap finction in MATLAB 2018b

[Jeff Miller]

See this answer

Answer 2

[Robert U]

Since the thread has be re-activated:

Here, a solution for heatmap tested in Matlab 2021b.

T = readtable('outages.csv');
h = heatmap(T,'Region','Cause');

% sloppy red line
annotation("line",[0.2 0.8],[0.2 0.8],"Color","red",'LineWidth',2)

% 2nd row horizontal line
plotLineThroughRowNr = 2;
nRow = numel(h.YData);
rowWidth = (h.InnerPosition(4))/(nRow);

lineYCoord = (nRow-plotLineThroughRowNr+0.5)*rowWidth + h.InnerPosition(2);

annotation("line",[h.InnerPosition(1) h.InnerPosition(1)+h.InnerPosition(3)],[lineYCoord lineYCoord],"Color","yellow",'LineWidth',2)

% 3rd column vertical line
plotLineThroughColumnNr = 3;
nColumn = numel(h.XData);
columnWidth = (h.InnerPosition(3))/(nColumn);

lineXCoord = (nColumn-plotLineThroughColumnNr+0.5)*columnWidth + h.InnerPosition(1);

annotation("line",[lineXCoord lineXCoord],[h.InnerPosition(2) h.InnerPosition(2)+h.InnerPosition(4)],"Color","magenta",'LineWidth',2)

Answer 3

[Ahmed]

Use MATLAB's imagesc instead of heatmap