How can I create a text box with position (x,y) on top of an image?

I have an image of discs and an accompanying n-by-2 matrix of disc centroid positions (x,y). I wish to plot the image and label each of the discs with a number.

When I attempt the obvious:

figure; imagesc(image1); hold on; daspect([1 1 1]); text(centers(1,1),centers(1,2),'X');

I receive the error message: "Subscript indices must either be real positive integers or logicals."

In fact, when I try the MATLAB-provided example:

x = 0:pi/20:2*pi; y = sin(x); figure; plot(x,y); text(pi,0,' \leftarrow sin(\pi)')

I receive the same error message.

Any idea what I'm messing up here?

Thank you very much, Michael

[Michael]

'clear all' seems to have fixed the issue. Thank you.

Answer 1

[Walter Roberson]

You probably had a variable named "text".

[Michael]

You're right. Thanks, Walter.