Re: From PaddedForm to numbers?
- To: mathgroup at smc.vnet.net
- Subject: [mg80514] Re: From PaddedForm to numbers?
- From: AES <siegman at stanford.edu>
- Date: Fri, 24 Aug 2007 01:55:45 -0400 (EDT)
- Organization: Stanford University
- References: <faj6fp$9gt$1@smc.vnet.net> <fajn99$pb1$1@smc.vnet.net>
In article <fajn99$pb1$1 at smc.vnet.net>,
David Bailey <dave at Remove_Thisdbailey.co.uk> wrote:
> PaddedForm is a wrapper - like MatrixForm, and many others. WRI have a
> standard comment in relation to these - "PaddedForm acts as a ?wrapper?,
> which affects printing, but not evaluation."
>
> The wording of this has always seemed to me unfortunate, because if you
> leave wrapper round an object it looks OK, but can't be incorporated in
> a further calculation - in other words a wrapper certainly does affect
> evaluation!
Amen. Been caught by this repeatedly with TableForm -- especially if
it's something like Table[ - - lengthy expression - - ]//TableForm.
If the standard comment were changed to something like " . . . affects
printing, but not evaluation *of the expression inside the wrapper*",
you'd at least.
By the way, if my test in 5.2 the other day was correct,
x=7; PaddedForm[x, 3, NumberForm->{"0",""} ]
produces 0007 -- which doesn't match my naive interpretation of "padding
something out to three significant figures", especially since it
expresses x = 7777 correctly as *four* significant figures. (It doesn't
make James Bond very happy either).