Tried to implement the Jacobian from C-code.
This though also report errors which are to small.
Maybe some scaling is wrong.
task #7822(https://gna.org/task/index.php?7822): Implement user function to estimate R2eff and associated errors for exponential curve fitting.
Authored by: tlinnet 2014-08-27
Parent: [r25329]
Child: [r25331]
