dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Sat, May 09, 2009 at 02:21:01PM +0200, Johan Hake wrote:
> On Saturday 09 May 2009 13:53:06 Anders Logg wrote:
> > On Sat, May 09, 2009 at 11:36:23AM +0200, Johan Hake wrote:
> > > On Saturday 09 May 2009 00:50:37 Anders Logg wrote:
> > > > On Fri, May 08, 2009 at 03:01:18PM +0200, Johan Hake wrote:
> > > > > On Friday 08 May 2009 14:57:11 Anders Logg wrote:
> > > > > > On Fri, May 08, 2009 at 02:49:01PM +0200, Johan Hake wrote:
> > > > > > > On Friday 08 May 2009 14:11:32 DOLFIN wrote:
> > > > > > > > One or more new changesets pushed to the primary dolfin
> > > > > > > > repository. A short summary of the last three changesets is
> > > > > > > > included below.
> > > > > > > >
> > > > > > > > changeset:   6101:f22b49031d081323d6c6ce18eccbb12c80240b22
> > > > > > > > tag:         tip
> > > > > > > > user:        Anders Logg <logg@xxxxxxxxx>
> > > > > > > > date:        Fri May 08 14:11:28 2009 +0200
> > > > > > > > files:       ChangeLog dolfin/parameter/NewParameter.cpp
> > > > > > > > dolfin/parameter/NewParameter.h dolfin/parameter/Parameters.cpp
> > > > > > > > dolfin/parameter/Parameters.h
> > > > > > > > dolfin/parameter/dolfin_parameter.h sandbox/misc/cpp/main.cpp
> > > > > > > > description:
> > > > > > > > Add initial version of new parameter system. See test in
> > > > > > > > sandbox/misc.
> > > > > > > >
> > > > > > > > Implementation similar to before, but much simplified as a
> > > > > > > > result of removing the ParameterValue class and subclassing
> > > > > > > > (New)Parameter directly.
> > > > > > > >
> > > > > > > > Implementation consists of two classes: Parameters and
> > > > > > > > (New)Parameter. Only supports int and double so far. Range
> > > > > > > > checks implemented.
> > > > > > > >
> > > > > > > > Check if this looks ok. Will continue to add more features.
> > > > > > >
> > > > > > > Looks nice. The info was a bit verbose for me, but that's
> > > > > > > details.
> > > > > >
> > > > > > I'm working on an ever more verbose version now, but it's prettier
> > > > > > and looks more like what you suggested to me a few days back.
> > > > >
> > > > > Ok!
> > > > >
> > > > > > > Will it be possible to
> > > > > > >
> > > > > > >   my_params.add("another params",my_other_params);
> > > > > > >
> > > > > > > where my_other_params is a Parameters?
> > > > > >
> > > > > > Yes, that should be possible to fix. And I guess you mean those
> > > > > > should then be nested? So after the above line, one may do
> > > > > >
> > > > > >   my_params["another params"]["foo"] = 1.0;
> > > > >
> > > > > Exactly!
> > > >
> > > > I've implemented this, but I had to change the last [] to ().
> > >
> > > Looks nice!
> >
> > Does this look like it will wrap nicely to Python?
> 
> Yes I think so. There we can also get rid of the operator()/[] problems we 
> face in c++.
> 
> We can also add attribute access:
> 
>   params.solver.tol = 1e-9
> 
> this will only work for parameter names with no white space. We will also be 
> able to add some convinient functions like, keys, values, items and 
> iter{keys,values,items}.
> 
> While addressing whitespace:
> Should we have some interpreter for this. Using po together with whitespace 
> parameters could cause some trouble.
> 
>   app --solver.abs tol 1e-9
> 
> vs:
> 
>   app --solver.abs_tol 1e-9

Maybe we should decide to not allow whitespace in key names. That way
a variable will be named similarly everywhere (including
command-line). We could also auto-replace "_" with " " from the
command-line but that may be confusing. Opinions?

> > Which features are missing now? I know of two things at least:
> >
> > 1. Adding value types bool and string
> 
> Should parameters of std::vector<Foo> be allowed? Nice for defining markers. 
> Here we cannot include any range checks. These should be wrapable to python 
> through typemaps.

We can store anything in the database, but std::vector<Foo> does not
look like a parameter to me. It looks like something that should be
associated with a mesh. Note that one can attach arbitrary arrays
(std::vector) to the data section of a mesh, both in the Mesh class
(mes.data()) and in XML.

> > 2. Command-line options (using po)
> 
> When you have desided on the syntax of the po, see an example above, it would 
> be nice to also include a to_option_str function which returns an option 
> representation of the Parameters. This is probably only convinent from 
> python, where one then can do:
> 
>   from app import default_params
>   p = default_params()
> 
>   jobs = []
>   for p1 in [0,1,3,4]:
>       p["p1"] = p1
>       for p2 in [0,1,2,3,4]:
>            p["p2"] = p2
>            jobs.append("python app " + p.to_option_str())
> 
>   submit(jobs)

What should this return? What is an "option representation"? Anyway,
it looks like it could be added on the Python side.

-- 
Anders

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