Differential Equation Function Transformations

[ChrisRackauckas]

Basic things like http://www.math.mcgill.ca/jakobson/courses/ma261/lecture5.pdf

This can really help enforce conditions like non-negativity since if your space doesn't allow it, then the numerical solver can guarantee it won't happen if it solves for exp(x) instead of x.

[stevengogogo]

it won't happen if it solves for exp(x) instead of x

Do you have a sample equation that has the problem you mentioned and can be benefited from this method?

[ChrisRackauckas]

https://www.radford.edu/~thompson/vodef90web/problems/demosnodislin/Demos_MOL/DemoPolymer/nonnegative.pdf

The one on the bottom of page 4 should be good.