Re: := vs = in some function definitions

*To*: mathgroup at smc.vnet.net*Subject*: [mg113280] Re: := vs = in some function definitions*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 21 Oct 2010 07:05:04 -0400 (EDT)

Anytime the function cannot be evaluated without a numerical value f[x_, n_: 50] := IdentityMatrix[n].Append[Range[n - 1], x]; Bob Hanlon ---- Sam Takoy <sam.takoy at yahoo.com> wrote: ============= Hi, Have read everything I could find regarding delayed assignment, I'm still not quite sure when to use which. For example, in the definition f[x_] = IdentityMatrix[50].Append[Range[1, 49], x]; could there ever be any reason to use := ? It seems that using := will condemn the function to repeated extra work every time its called. So could there be a situation where the use of ":=" for the above function is recommended? Many thanks in advance, Sam