Re: Mathematica question

*To*: mathgroup at smc.vnet.net*Subject*: [mg124805] Re: Mathematica question*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Tue, 7 Feb 2012 04:06:37 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201202060739.CAA10233@smc.vnet.net>*Reply-to*: murray at math.umass.edu

Yikes: it seems to me that's exactly the sort of expression combining Postfix with the /@ special input form and pure functions that one should _not_ write! The principal purpose of such special input forms should be to make expressions easier to read (and write), not more. On 2/6/12 2:39 AM, Howie wrote: > Let's say you've got an expression > > expr = {Sin[x] + x^2 - x^2*Cos[x], x^3 (1 + x^2) - x^3, x^4 - x^3} > > What does this mean? > > Table[expr[[j]] // FullSimplify[#, $assumptions]& /@ #& // Expand // > @ #&, {j, 3}] > > I am new to Mathematica as far as these more complicated expressions > are concerned. > > Can you explain symbol by symbol? > > I realize that the [[j]] is Part and that FullSimplify is applied // > Postfix to expr, but I don't understand what $assumptions means (I'm > assuming that these are some assumptions added to FullSimplify) but I > do not know where these assumptions come from. Are these assumptions > the rest of the stuff on the right-hand side? > > In reality I have a potentially much more complicated form of the > expr. > > Thanks! > > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Mathematica question***From:*Howie <hcohl001@gmail.com>