Probability visualization with color scale

Hi, I have a 296x296 matrix. Each cell in the matrix represents a probability of occurence, [0,1]. I want to create a grid or heatmap where the color of the square corresponds to the probability of occurence - the darker the cell the greater the probability. I have used histogram bins for this matrix and it didn't really represent the data the way that i wanted. I'd like to have something similar to this below, which was done using color scales in Excel.

Answer 1

[Image Analyst]

imshow(yourMatrix, []);
colormap(hsv(256));
colorbar;

[Emma Kuttler]

This works! Is there a different way to add the tic marks on the axes? They aren't visible even when I change the size in figure properties.

[Image Analyst]

axis('on', 'image');