[SciPy-user] scipy.optimise.lbfgsb /bounded optimization help

Robert Kern robert.kern at gmail.com
Sat Jan 27 16:40:47 CST 2007

mclaugb wrote:
> I can make the function map to a scalar--though i thought multivariate 
> algorithms used vector differentials between iterations. 

"Multivariate" describes the input of the objective function, not the output.
None of the optimizers in scipy are multiobjective optimizers.

> Note, the error 
> below is the same regardless of whether the function provides a scalar or 
> vector.
> i seem to be receiving this error:
> x, f, d = lbfgsb.fmin_l_bfgs_b(Permmin, x0, approx_grad=1,args=params, 
> bounds = [(.0001, 1000),(.0001, 1000)])
>   File "C:\Python24\lib\site-packages\scipy\optimize\lbfgsb.py", line 197, 
> in fmin_l_bfgs_b
>     isave, dsave)
> ValueError: failed to initialize intent(inout) array -- expected elsize=8 
> but got 4 -- input 'l' not compatible to 'd'

And as I asked you on comp.lang.python, what platform are you on? What FORTRAN
compiler are you using to build scipy? I think this is a 64-bit problem, but
until you give us that information, we can't help you.

Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco

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