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.