Re: Caching of values and delayed sets

*To*: mathgroup at smc.vnet.net*Subject*: [mg39705] Re: Caching of values and delayed sets*From*: Nafod40 <may106 at SPAMAWAYpsu.edu>*Date*: Mon, 3 Mar 2003 04:25:05 -0500 (EST)*Organization*: Penn State University, Center for Academic Computing*References*: <b3pgdu$7hr$1@smc.vnet.net> <b3rt4q$dnr$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Thanks for the answers, guys. Let me make it a little more complicated. Between two evaluations of A the value for slow[ ] might change. It won't change during an evaluation of A, but it will change between one evaluation and another. What I do now, that works for my problem fine is to say... eval = Block[{C = slow[ ]}, A]; This does what I need for the trivial problem I posed, but I might have a whole slew of slow computations that get repeated in a single evaluation of A. I'd like to have each of them run once and cache, but I'd like to not have to go through the trouble of identifying them. Currently I have large expressions for a variable like A that call functions like C:= slow[ ] repeatedly, and it is slowing down the calculating of A something firece. I don't think it can be done simply, but figured it would not hurt to ask. Orestis Vantzos wrote: > C:=(C=slow[...]) > should work... > Orestis > > may106 at psu.edu (Nafod40) wrote in message news:<b3pgdu$7hr$1 at smc.vnet.net>... > > Hola Amigos, > > > > I have a variable A that depends via a delayed set on variables B1 > > through B1000 that each depend via delayed set on variable C and other > > a mixture of the other B's, which delayed set depends on some slow to > > calculate function C:= slow[ ]. If you explode out the tree view of A > > symbolically, the variable C might appear 5000 times in a messy > > acyclic dependency graph. > > > > How do I inject some smarts, so that, when asking for the value of A, > > I only evaluate C:=slow[ ] once, and cache it and use the cached value > > for every other time that I need C?