Menu
▾
▴
[Maxima-bugs] [ maxima-Bugs-902290 ] Nonsimplifying nounforms: abs, realpart, carg, etc.
|
From: SourceForge.net <no...@so...> - 2007-01-12 11:25:50
|
Bugs item #902290, was opened at 2004-02-22 15:11 Message generated for change (Comment added) made by willisbl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=902290&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Lisp Core - Simplification Group: None Status: Open Resolution: None Priority: 8 Private: No Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: Nonsimplifying nounforms: abs, realpart, carg, etc. Initial Comment: declare(q,complex)$ expr: rectform(q) => 'realpart(q) + %i * 'imagpart(q) subst(1,q,expr) => 'realpart(1) + %i * 'imagpart(1) (no simplification!) ----------------- Several Maxima mathematical functions do not simplify correctly as nounforms. As a general rule, simplifications should happen with all mathematical-function nounforms. For example, sin(0) == 'sin(0) == cos(%pi/2) == 'cos(%pi/2) == 0 But the following don't simplify: 'abs(1) 'realpart(1) 'imagpart(1) 'carg(1) Note also that cabs/carg are not treated symmetrically. cabs is an expression-manipulating function (like factor) which can return the mathematical operator abs. But there is no mathematical operator corresponding to the expression-manipuating function carg (cf also bug 620246). ---------------------------------------------------------------------- >Comment By: Barton Willis (willisbl) Date: 2007-01-12 05:25 Message: Logged In: YES user_id=895922 Originator: NO Isn't the 'abs(1) --> abs(1) bug a noun / verb confusion (mabs vs %mabs)? Just doing (setf (get '%mabs 'operators) 'simpabs) allows 'abs(1) --> 1. The test suite is OK with (setf (get '%mabs 'operators) 'simpabs). ---------------------------------------------------------------------- Comment By: Robert Dodier (robert_dodier) Date: 2006-07-23 13:41 Message: Logged In: YES user_id=501686 Observed in 5.9.3cvs. Also increasing the priority -- this is a very weak point for Maxima. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=902290&group_id=4933 |