Re: [Help-glpk] GLPK for Java - problem - exception thrown for glp_find_col

[xypron . glpk]

Hello Andrew

> > The documentation leaves it unmentioned that the index is updated when
> 
> > a new column or row
> 
> > is added after calling glp_create_index.
> 
> 
> 
> On adding/removing named rows/columns the index is updated (if exists).
> 

Kindly add this information to the glp_create_index documentation. Otherwise a 
user might think he has to create a new index after a structural change of the 
problem.

Best regards

Heinrich Schuchardt

http://www.xypron.de

Am 02.05.13 um 13:48 schrieb Andrew Makhorin

> > please, update the documentation to clearly point out that an error is
> 
> > thrown in glp_find_col
> 
> > and glp_find row if not preceded by a call to glp_create_index.
> 
> 
> 
> Okay, I will add a paragraph to clarify the issue.
> 
> 
> 
> >  
> 
> > Wouldn't it be a good idea to let these functions implicitly call
> 
> > glp_create_index, if the
> 
> > index is missing?
> 
> 
> 
> I don't think so. It would be a sort of obscure feature, when the
> 
> program does something that it shouldn't do (if the feature is
> 
> disabled), and the user doesn't know about that.
> 
> 
> 
> >  
> 
> > The documentation leaves it unmentioned that the index is updated when
> 
> > a new column or row
> 
> > is added after calling glp_create_index.
> 
> 
> 
> On adding/removing named rows/columns the index is updated (if exists).
> 
> 
> 
> >  
> 
> > Why is the index not always created when creating a new problem? The
> 
> > overhead of the index seems to be negligible.
> 
> 
> 
> This feature is optional, because in most cases the name index is not
> 
> needed. If necessary, the user may easily enable this feature by a call
> 
> to glp_create_index immediately after glp_create_prob.