Re: Subscripted variables and FindRoot?

*To*: mathgroup at smc.vnet.net*Subject*: [mg26719] Re: Subscripted variables and FindRoot?*From*: Brian Higgins <bghiggins at ucdavis.edu>*Date*: Thu, 18 Jan 2001 00:57:21 -0500 (EST)*References*: <943eq7$cpr@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Mike, A pattern variable in the definition of a function must be a Mathematica Symbol. A subscripted variable is a composite box structure, and so cannot be used as a pattern variable. Using your notation, the subscripted varible Xx is stored as Subscript{X,x], and not as asymbol. However, if you load the Notation package <<Utilities`Notation` Then you can use the Symbolize function to turn the Subscript[X,x] into a Symbol. Thus Symbolize[Xx] You can now use Xx as a pattern variable, but be sure to place a colon after the symbolize variable in the pattern definition. i.e myFunc[Xx:_]:=Sin[Xx] Use the palette to enter Symbolize. Regards, Brian You can use the Notation packageIn article <943eq7$cpr at smc.vnet.net>, Mike Yukish <may106 at psu.edu> wrote: > Hello, > > I love using subscripted variables for readability, but they seem to > have their limitations. FindRoot[ ] seems to burp when presented with a > function that takes a subscripted variable as input. Also, and probably > related, how do you declare a subscripted variable as a pattern for a > function? Patterns and subscripts seem to clash. > > This is no problem... > > foo[x_]:= x^2 > > This is a problem (read Xy as x-subscripted-y) > > foo[Xy_] := Xy^2 > > Where it does not recognize compute z^2 when presented with > > foo[z] > > Any hints on how to work with them? > > Sent via Deja.com http://www.deja.com/