       Re: A Mathematica implementation of SolvOpt

• To: mathgroup at smc.vnet.net
• Subject: [mg88610] Re: A Mathematica implementation of SolvOpt
• From: tommcd <TCMcDermott at gmail.com>
• Date: Fri, 9 May 2008 07:17:42 -0400 (EDT)
• References: <g00uq4\$gi1\$1@smc.vnet.net>

```it's probably obvious but the Fortran equivalent should of course have
been
Where(g0 >= 0.0)
deltax = h1*ddx
ElseWhere
deltax = -h1*ddx
End Where
On May 9, 8:34 am, tommcd <TCMcDerm... at gmail.com> wrote:
> Hi,
> I recently uploaded a Mathematica implementation of SolvOpt
> (an implementation of Shor's r algorithm for the minimization of
> nonlinear, possibly non-smooth objective functions) tohttp://www.mathematica-users.org/webMathematica/wiki/wiki.jsp?pageNam...
> The main package is SolvOpt.m, with shorTest.m and the notebook
> SolvOptTest.nb being for demonstration purposes.
> The original (Fortran, C, and other) implementations and documentation
> are available athttp://www.uni-graz.at/imawww/kuntsevich/solvopt/
>
> As this is my 1st mathematica package (I've only ever used notebooks
> interactively before) I'd
> appreciate any suggestions or constructive criticism, especially with
> regard to efficiency and style.
>
> For example I'd like a more efficient and elegant way to express
> Do[
>    deltax[[j]] = If[  g0[[j]] >= 0.0, h1*ddx, -h1*ddx]
> , {j,n}
> ];
>
> which in Fortran 95 can be written very clearly as
>
> Where(g0 >= 0.0)
>     g0 = h1*ddx
> ElseWhere
>     g0 = -h1*ddx
> End Where
>
> where g0 can be any array of up to 7 dimensions, & any number of array
> assignments
> can appear in each section (not just the one shown here), moreover the
> 'Where' can itself
> be nested inside another where etc.. For now a construct which works
> for the 1D list above
> and avoids the do loop would be fine, though if there is a general
> method for masked array assignments in Mathematica I love to hear