Bug fix: The 1-norm of a vector
The following bug (among others) has been fixed in patchlevel 1 (for Windows). The EC1 patch is available from Maple (http://www.maplesoft.com/patches.html). Recently-purchased copies of Maple may already have the patch installed.
The norm function in the linalg package computes various norms of vectors and matrices. In particular, if v is a vector or list and p >= 1 , norm(v,p) should be the Minkowski norm for power p . Thus:
Warning, new definition for norm
Warning, new definition for trace
> v:= vector([v1, v2]): norm(v,3);
However, it doesn't work in Release 5 for p = 1 unless _Envsignum0 is set to 1.
> _Envsignum0:= '_Envsignum0';
Error, (in norm) invalid vector norm, 1
> _Envsignum0:= 1: norm(v,1);
For convenience, I have written a replacement for norm which temporarily sets _Envsignum0 to 1, then calls the original norm procedure. _Envsignum0 is restored to its original value when this exits. To use this bug fix, after loading the linalg package execute the command
At this point the norm command should work correctly.
linalg , linalg[norm] , patchlevel 1 , signum
Maple Advisor Database R. Israel 1998