Constraint evaluation in NMinimize

*To*: mathgroup at smc.vnet.net*Subject*: [mg122651] Constraint evaluation in NMinimize*From*: Ray Koopman <koopman at sfu.ca>*Date*: Fri, 4 Nov 2011 06:02:47 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

I want to minimize f[x] with respect to x, subject to g[x]. Both f and g depend in part on h[x], so to avoid calculating h[x] twice I use an auxiliary variable: NMinimize[{t = h[x]; f[x,t], g[x,t]}, {x}]. That appears to work, but it depends on the constraint never being evaluated without first evaluating the minimand, and I can't find anything in the documentation that says that that will always be the case. Can anyone help? (I asked a similar question several years ago, at which time DrBob pointed me to sec 2.6.4 in the book, but it's not obvious to me if the standard evaluation procedure necessarily applies here.)

**Follow-Ups**:**Re: Constraint evaluation in NMinimize***From:*Daniel Lichtblau <danl@wolfram.com>