Re: Matrices, TraditionalForm and Two Equal Signs
- To: mathgroup at smc.vnet.net
- Subject: [mg100966] Re: Matrices, TraditionalForm and Two Equal Signs
- From: C Rose <uk.org.microserf at googlemail.com>
- Date: Thu, 18 Jun 2009 20:48:38 -0400 (EDT)
- References: <h19i25$p00$1@smc.vnet.net> <h1cva7$jgv$1@smc.vnet.net>
Thanks for this solution.
Chris
> It looks like what's happening is that the equality is being
> simplified: Mathematica recognizes that a.b == N[a.b] is True, and so
> drops the last part.
>
> As you say, one way around this would be to use a Hold construct. It's
> a bit fiddly because you need the a.b and N[a.b] to evaluate before
> applying the Hold. The following is one way to do this (there is
> probably a neater way):
>
> HoldForm[#1 == #2 == #3] &[A B, a.b, N[a.b]] // TraditionalForm
>
> By using this anonymous function construct, the three arguments to
> Equal are first evaluated, then the HoldForm prevents further
> evaluation.
>
> Another, possibly simpler, solution would be to use a Row construct:
>
> Row[{A B, " \[Equal] ", a.b, " \[Equal] ", N[a.b]}] // TraditionalForm
>
> The downside here is that this can no longer be evaluated (whereas in
> the previous case you could use ReleaseHold) -- though this is
> probably not an issue.