Create color scatter plot

I have a set of (x,y) points, in which several (x,y) points occur multiple times. When I make a normal scatter plot of these points, I cannot see the amount of times each point is occuring the dataset. Therefore I want to use colors in the scatter plot to show how many times the points are occuring.

I know how to count the occurrence in each cell using hist3(x,y), but how can I eventually create the plot that I want? To use scatter I need end up with:

• x & y containing the unique points in the dataset
• z containing the number of times each points occurs

[monnq]

About 4000. I know how to eventually create the scatter plot and adjust the colors. I am now looking for an easy way to create the inputs for the scatter plot, i.e. x,y points occuring together with the number of times z they occur.

Answer 1

[Image Analyst]

You can pass in a list of colors into scatter that says the color of each marker. Just make up your colors and pass it in.

Use the histogram count as an index into a standard colormap like winter, summer, autumn, hot, cool, etc.

myColors = winter(256); theIndex = 256 * histogramCounts(thePointsIndex) / max(histogramCounts) myColors(thePoint, :) = winter(theIndex, :);

Do the above for every point in your data set, then pass in to scatter() or scatter3().

[monnq]

Thanks, now the only thing remain how can I easily link the indices of the datapoints to the indices of the matrix resulting from hist3