How to do scatter/plot overlaying an imagesc/pcolor plot?

I have a matrix (200 x 200), which I do: imagesc(v(1:200),v2(1:200), matrix); This is an extrapolated Matrix, and now I wish to scatter / plot my data point observations locations on top of this matrix field.

How would I go about doing this? I thought maybe I could imagesc a matrix of the scattered observation with increased transparency? but I guess there must be a better way to do this..

Answer 1

[Image Analyst]

Don't use pcolor() unless you're happy not displaying the last row and column of your image.

To overlay one image on top of another, see these links:

http://www.mathworks.com/matlabcentral/answers/104889-how-to-overlay-a-foreground-image-over-a-background-image

http://blogs.mathworks.com/steve/2009/02/18/image-overlay-using-transparency/

To plot or scatter points, then just call hold on and then scatter() or plot():

imshow(yourImage);
hold on;
plot(x,y, 'rd', 'MarkerSize', 30); % Plot red diamonds over image.

[Michael]

Thanks for your help, however, I am not using images, I am using imagesc (although, now contourf) to display data. How would I do it in this case?

[Adam]

The general idea should be the same whatever function you are using to plot your image data.