Re: Pattern Syntax for Alternate Heads with Default Value

*To*: mathgroup at smc.vnet.net*Subject*: [mg125863] Re: Pattern Syntax for Alternate Heads with Default Value*From*: Murta <rodrigomurtax at gmail.com>*Date*: Thu, 5 Apr 2012 05:51:39 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jlh0n6$t6m$1@smc.vnet.net>

On Apr 4, 5:28 am, Ben <ben... at gmail.com> wrote: > I'm trying to build a unary function which accepts only arguments with > two possible heads and has a default value. That is, something like > the following, except that this doesn't work. Anyone know how to do > this correctly? > > f[(x_Real | x_Integer) : 2.5] := x^2; > where f[3] = 9 > and f[1.5] = 2.25 > and f[] = 6.25 Hi Ben Maybe something like that? f[x_ (Real | Integer)] := x^2; f[] = 6.25; (But all Integer are Real, I don't understand the application. It could be f[x_Real: 2.5] := x^2) best regards Murta