Re: Evaluation Control

*To*: mathgroup at smc.vnet.net*Subject*: [mg14877] Re: [mg14858] Evaluation Control*From*: BobHanlon at aol.com*Date*: Mon, 23 Nov 1998 10:11:55 -0500*Sender*: owner-wri-mathgroup at wolfram.com

In a message dated 11/20/98 4:45:54 AM, phantomlord at my-dejanews.com writes: >I am writing a function which involves manipulation of lists, but have >stumbled across a problem. It seems as though when I call >"Print[list[i]]" in a Do[] loop (where i is the iterative variable) it >returns the following: {0.,.2,.4,.6,.8,1.}[i] i.e. it hasn't referenced >the one element I require for computation in the rest of the code. > >I try to evaluate a function f[x] at x=list[i], which returns: >Cosh[{0.,.2,.4,.6,.8,1.}[i.]]+....bla bla bla so it seems that it >interprets i as a decimal and NOT an integer, is this the cause of the >problem or is there something else I am doing wrong? > Paul, x = Table[Random[], {10}] {0.390142,0.945503,0.585519,0.812327,0.0641894,0.728559,0.729633,0.516246, 0.652987,0.446624} If the function is Listable, then just apply the function to the list ??Cosh "Cosh[z] gives the hyperbolic cosine of z." Attributes[Cosh] = {Listable, NumericFunction, Protected} Cosh[x] == Cosh /@ x == Table[Cosh[x[[i]]], {i, 10}] True If the function is not Listable, then map it onto the list f[x] f[{0.390142,0.945503,0.585519,0.812327,0.0641894,0.728559,0.729633,0.516246, 0.652987,0.446624}] f /@ x {f[0.390142],f[0.945503],f[0.585519],f[0.812327],f[0.0641894],f[0.728559], f[0.729633],f[0.516246],f[0.652987],f[0.446624]} f /@ x == Table[f[x[[i]]], {i, 10}] True Bob Hanlon