Re: expression formatting inside tables

*To*: mathgroup at smc.vnet.net*Subject*: [mg54682] Re: expression formatting inside tables*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Sun, 27 Feb 2005 01:29:06 -0500 (EST)*Organization*: The University of Western Australia*References*: <cvk3vk$d93$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <cvk3vk$d93$1 at smc.vnet.net>, "David Park" <djmp at earthlink.net> wrote: > Trevor, > > foo[x_] := x^2 > > Table[{HoldForm[foo[j]], foo[j]} /. j -> i, {i, 5}] // TableForm > > If you look up the Table Help and then follow the link to Section A.4.2 on > evaluation of iteration functions you will see why this is necessary. Table > essentially creates a Block environment, sets i to an iterator value and > then evaluates the argument. But HoldForm[foo[i]] does not evaluate so it > does not get changed. > > However, you can substitute into held expressions using Rules. I think a more elegant solution is foo[x_] := x^2 p[i_] = {HoldForm[foo[i]], foo[i]} Table[p[i], {i, 5}] // TableForm Cheers, Paul -- Paul Abbott Phone: +61 8 6488 2734 School of Physics, M013 Fax: +61 8 6488 1014 The University of Western Australia (CRICOS Provider No 00126G) 35 Stirling Highway Crawley WA 6009 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul