Constraints on fitting parameters with Python and ODRPACK
I'm afraid that the older FORTRAN-77 version of ODRPACK wrapped by scipy.odr does not incorporate constraints. ODRPACK95 is a later extension of the original ODRPACK library that predates the scipy.odr wrappers, and it is unclear that we could legally include it in scipy. There is no explicit licensing information for ODRPACK95, only the general ACM TOMS non-commercial license.
I'm using the ODRPACK library in Python to fit some 1d data. It works quite well, but I have one question: is there any possibility to make constraints on the fitting parameters? For example if I have a model y = a * x + b and for physical reasons parameter a can by only in range (-1, 1). I've found that such constraints can be done in original Fortran implementation of the ODRPACK95 library, but I can't find how to do that in Python.
Of course, I can implement my functions such that they will return very big values, if the fitting parameters are out of bounds and chi squared will be big too, but I wonder if there is a right way to do that.