I have rainfall data that I want to interpolate using spline. I have done Spline Interpolation, only that the values produce negative predicted values which is basically wrong. There should be no negative rainfall value.
How can I set lower limit to zero or set a true value limit?
I am using ArcGIS Desktop 10.0.
Best Answer
Part of the question is whether you want a "sawed-off" floor, which you would get with approaches like the one recommended by @radouxju. This is usually fine and is really pretty easy to do.
If you want to get a little fancier and have the algorithm respect that floor and fit it into the overall interpolation a little more smoothly, then try to use an interpolation algorithm that lets you limit the minimum values (and maximum ones, too!). One example is
TopoToRaster.