I'm working with a function, scipy.optimize.fmin_bfgs, which has several output variables. I care about two of them, xopt and fopt. How do I store these variables? The following isn't working for me:
xopt, fopt = fmin_bfgs(f, 0, fprime = fprime)
However, this gives me fopt:
fopt = fmin_bfgs(f, 0, fprime = fprime)
I need xopt too, but it says that I "need 1 more value to unpack."
You need to set full_output to true, after which fopt, func_calls, grad_calls, and warnflag are included too; you can slice the returned sequence:
xopt, fopt = fmin_bfgs(f, 0, fprime = fprime, full_output=True)[:2]
See the scipy.optimize.fmin_bfgs documentation:
full_output: bool, optional
If True,return fopt, func_calls, grad_calls, and warnflag in addition to xopt.
Granted, the documentation for this function makes this far from obvious, I first had to look at the linked source code. By the looks of it, bopt and gopt are also included when full_output is set, but the documentation fails to properly explain this.
