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Re: Mathematica question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg124812] Re: Mathematica question
  • From: DrMajorBob <btreat1 at austin.rr.com>
  • Date: Wed, 8 Feb 2012 05:28:02 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • References: <201202060739.CAA10233@smc.vnet.net>
  • Reply-to: drmajorbob at yahoo.com

It's the sort of grammar up with which we should not put!

Bobby

On Tue, 07 Feb 2012 03:06:37 -0600, Murray Eisenberg  
<murray at math.umass.edu> wrote:

> 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!
>>
>>
>


-- 
DrMajorBob at yahoo.com



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