Re: FindMinimum constraints

*To*: mathgroup at smc.vnet.net*Subject*: [mg92986] Re: FindMinimum constraints*From*: dantimatter <google at dantimatter.com>*Date*: Wed, 22 Oct 2008 05:37:33 -0400 (EDT)*References*: <gdja4r$idt$1@smc.vnet.net> <gdjq6u$mtu$1@smc.vnet.net>

Thanks for the quick response. Join[] did indeed do the trick. But adding this constraint introduced another problem. By fixing a[100] == 0.5*(a[0] + a[25], I (inadvertently) allowed FindMinimum to choose solutions that seem to have discontinuous derivatives (i.e., there are really sharp points at a[100], a[0], and a[25]). I guess I should also somehow force the solution to be sufficiently 'smooth'. Is there an easy way to do that? Thanks again for all the help! Dan On Oct 21, 1:43 am, Jean-Marc Gulliet <jeanmarc.gull... at gmail.com> wrote: > dantimatter wrote: > > I have a large and complicated model for which I'm using the > > FindMinimum function to find a solution. The solution consists of 10= 1 > > numbers a[i] (i goes from 0 to 100), all greater than zero, and the > > search for each a[i] begins at 0.001: > > > sol = FindMinimum[{model, Table[a[i] > 0,{i, 0, 100}]}, Table[{a[i], > > 0.001},{i, 0, 100}]]; > > > The line of code that I'm showing here works great. My problem now i= s > > that I'd like to add an additional constraint: that a[100] == > > 0.5*(a[0]+a[25]). I can't for the life of me figure out how to > > include this added constraint in the line of code that already works. > > I get errors when I use Append[] to the Table. I would appreciate any > > thoughts on this. > > Using *Join* should do the trick. For instance, > > sol = FindMinimum[{model, > Join[{a[100] == 0.5*(a[0] + a[25])}, > Table[a[i] > 0, {i, 0, 100}]]}, Table[{a[i], 0.001}, {i, 0, 10= 0}]] > > Regards, > -- Jean-Marc