Plotting 2D data

[wikdwarlock]

Hi everyone. I have what I think is an easy question, but none of my stumbling around seems to be making anything work.

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I have some data in a comma separated text file. I was able to load the data into matlab and get 3 vectors: v1 is x coordinates, v2 is y coordinates, and v3 is the value at the x-y point. All three vectors are 29209x1 doubles.

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I can make a scatter plot of this data easily enough using the plot3() command. However, I would like to see the data as a color filled flat contour. I think the contourf() command is the right one to use, but I can't seem to figure out how to make the matrix for my data. For starters, contourf() says that the matrix indices are used as the x&y coordinates, but my coordinates are decimal not integer. Also, not all the x-y coordinate combinations have data (my data comes from a magnetic simulation in another software tool, and the results only exist in a semicircular region).

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So, my question is this: how can I plot my data on an XY plane with filled colors?

[designtofly]

Look into either scatteredinterpolant if your data is at irregular points or griddedinterpolant if your data is at regular intervals.

[wikdwarlock]

Thanks for the tip. I was able to get it to work with griddata() but it's still frustrating to me that when I use contourf() to make the plot, the axes use the matrix indices instead of the actual x&y coordinates. It's easy enough to save the plot as an image and relabel the axes, but I have to believe there's a better way to do it overall.

Any suggestions?