Re: Unexpected non-evaluation problem
- To: mathgroup at smc.vnet.net
- Subject: [mg63180] Re: Unexpected non-evaluation problem
- From: David Bailey <dave at Remove_Thisdbailey.co.uk>
- Date: Fri, 16 Dec 2005 07:22:48 -0500 (EST)
- References: <dnrch3$kie$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hello, I don't think this is anything to do with the mathematical properties of the fourier transform - I think it is a bug caused by the fact that one transform is nested inside another. If you remove the ReadProtected attribute on InverseFourierTransform and spill out all the top-level code for the operation, you find that some cases of the function are conditional on System`FourierTransformDump`$FourierExptransform - a global variable - so maybe the two levels interfere with each other. The interesting thing is that you end up with an expression that Mathematica thinks is fully evaluated when in fact it is not! That is normally pretty hard to do. BTW, I assume that if WRI did not want people to read the code for internal functions such as InverseFourierTransform, they would have prevented users from clearing the ReadProtected attribute! David Bailey http://www.dbaileyconsultancy.co.uk