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Re: expression formatting inside tables


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

-- 
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