[SciPy-dev] one more scipy.optimize.line_search question

Alan G Isaac aisaac@american....
Mon Aug 6 15:29:56 CDT 2007

On Mon, 06 Aug 2007, dmitrey apparently wrote:
> I wonder what does the parameter amax=50 mean (in 
> optimize.line_search func)?  Seems like this parameter is 
> never used in the func

Is there something wrong with the minpack2 documentation?

c       stpmax is a double precision variable.
c         On entry stpmax is a nonnegative upper bound for the step.
c         On exit stpmax is unchanged.

> moreover, amax is defined in scipy.optimize module as 
> a func

I think you are confusing this with the numpy array method?

> Also, in the middle of the func it has line 
> (optimize.py)
> maxiter = 10 
> this one seems to be very small to me. 
> don't you think it's better to handle the param in input args? 

That is just for the bracketing phase.
Are any troubles resulting from this value?

> Also, don't you think that having 2 line_search funcs is ambiguous? 
> (I mean one in scipy.optimize, python-written, and one in 
> scipy.optimize.linesearch, binding to minpack2)

It would be nice to have some history on this.
I expect we'll have to wait until Travis has time to look
this discussion over, which may not be soon.

Alan Isaac

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