MathGroup Archive 2000

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

Search the Archive

Re: Consrtaining Variables


With version 4, try using assumptions with Simplify or FullSimplify

Simplify[Abs[a - x], x >= a]

x - a

Factor[Sum[Simplify[Abs[a - x], x >= a], {x, a, 10}]]

(1/2)*(a - 11)*(a - 10)

Sum[Simplify[Abs[a - x], {x >= a, a >= 5}], {x, 0, 10}]

6*a + Abs[a - 10] + Abs[a - 9] + Abs[a - 8] + Abs[a - 7] + 
  Abs[a - 6] - 15


Bob Hanlon

In a message dated 12/30/00 2:20:27 AM, frumple*NOSPAM* at home.com writes:

>I am working on a package where I need to constrain the domain of some
>
>variables to the non-negative integers. In particular I would like to be
>
>able for Mathematica to recognize that Abs[a-x] = x-a when x>=a where 
>the Abs term is in both the limits and kernal of a Sum.
>


  • Prev by Date: RE: Launch Directory
  • Previous by thread: Consrtaining Variables
  • Next by thread: How can I obtain an echelon form of a Matrix in Mathematica?