Plotting a heat map with two variables with color dependent on third variable

I have a matrix of x and y values, and I would like to plot them using a heat map. However, there is also a third column in the matrix of z-values, which I would like to determine the color of each point in the heat map. How would I do this?

[Jess Lovering]

You should start by looking into the help for the pcolor plot. Is this the graphic that you are trying to achieve?

[Chinwe Orie]

Something like that yes, especially the checkered plot. That would be very ideal. My x and y are both 1xn vectors (n is something like 5000 for example). My z-variable is also a 1xn vector. However, the color input has to be a matrix. I'm not sure how I would use my z-variable to control color variation if the color input has to be a matrix.

[Chinwe Orie]

%code 
PC = [drops;heatfreqs;heatprom]; %drops, heatfreqs and heatprom are all 1x65550 vectors
PC = squeeze(PC);
pcolor(PC)
shading interp
colorbar    

I've tried the above code, but all it gets me is a pcolor plot that doesn't take into account any of the values in the matrix. It just plots based on the coordinates of the matrix itself. I have attached a photo of what the graph looks like.

Answer 1

[Poonam Mahapatra]

You can make a table of Xdata, Ydata and Cdata where Xdata is the variable having data to be displayed along the x-axis, Ydata is the variable having data to be displayed along the y-axis and Cdata is the variable having values to determine the color of each cell, using the following command:

>> tb1 = table(Xdata, Ydata, Cdata);

Then you can plot the heatmap using the following command:

>> h = heatmap(tb1,'Xdata','Ydata','ColorVariable','Cdata');

Please refer to the following documentation for more details:

https://in.mathworks.com/help/matlab/ref/heatmap.html