### Update: data [here](http://pastebin.com/HHrC95d0)

Here is a contour plot produced in the SAS program:
![enter image description here](https://i.stack.imgur.com/Km8Yc.png)

In this plot, variable 23405 forms the X axis, variable 20201 forms the Y axis, and outcome variable 50502 forms a pseudo Z axis via color and contour lines. As one can readily see, the red patch marks the "sweet spot" as far as combining 23405 and 20201.

THE DATA: X and Y variables are continuous, with the range shown on both axes. The original Z data is continuous as well. However what is shown in the plot are not the original data. Z was "massaged" or "smoothed," based on the original Z data, so as to allow for the creation of the smooth-looking contour plot. In this sense, the surface shown itself does not pass through (precisely) the original Z points, but is an estimation. (Analagous to a single linear regression line not passing through all the data points.) This approximating process done by the particular program used (SAS vs. Mathematica vs. other) is what I'm particularly curious about. Bottom line -- will the supposed "sweet spot" arrived at be any different?

Using the same data, I would like to create a similar -- or even better -- contour plot in Mathematica. At the very least, to compare it with the one from SAS, to see if the conclusions appear to be the same.

There seem to be various ways of creating such plots in Mathematica, a few of the methods just recently added to the program in version 8.

Some possible ways in Mathematica:

* [ListContourPlot](http://reference.wolfram.com/mathematica/ref/ListContourPlot.html)
* [SmoothKernelDistribution](http://reference.wolfram.com/mathematica/ref/SmoothKernelDistribution.html)
* [SmoothDensityHistogram](http://reference.wolfram.com/mathematica/ref/SmoothDensityHistogram.html)

And other ways as well.

I'm hoping someone here has had experience creating such contour plots in Mathematica, and can share insights as to which approach has worked well for him/her. Also, any added tricks or parameters needed to arrive at an optimal output?