[Date Index] [Thread Index] [Author Index]

Re: StringForm bug?

• To: mathgroup at smc.vnet.net
• Subject: [mg65488] Re: StringForm bug?
• From: David Bailey <dave at Remove_Thisdbailey.co.uk>
• Date: Wed, 5 Apr 2006 06:55:28 -0400 (EDT)
• References: <e0dp2k$q6p$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

pdickof at scf.sk.ca wrote:
> I create a form...
> 
> myForm = " Line `1`\n
> Line `2`\n
> Line `3`"
> 
> Executing the StringForm line below gives me what I expect and want...
> 
> StringForm[myForm, 1, 2, 3]
> 
> but if I try to create an ordinary String from the StringForm object...
> 
> InputForm[ToString[StringForm[myForm, 1, 2, 3]]]
> 
> ... I get...
> 
> " Line 1      2      3\n        Line   Line "
> 
> Which is apparently wrong and certainly not what I want. How do I get
> this to work?
> I am running Mathematica 5.2
> 
> Thanks in advance.
> Peter Dickof
> 
Hi,

I am not sure I would classify this as a bug, but if you look at the 
help for StringForm, it says

"StringForm acts as a wrapper, which affects printing, but not evaluation."

This seems to be Wolfram-speak for "Useful as a wrapper for printing, 
but nothing else!" These wrappers - such as MatrixForm - often get left 
in expressions that are used elsewhere, and they cause a lot of mischief!

In this case, there is no reason to expect ToString to operate usufully 
on your StringForm - and it doesn't!

I would use StringReplace to achieve what you want to do. The 
replacements must be strings - but you can use ToString to achieve that.

David Bailey
http://www.dbaileyconsultancy.co.uk