Bug #1191
ApproxSolve: log(0) on some examples
Description
The following input attempts to compute log(0).
use QQ[x,y,z]; L := [y^3 +x*z^2, 2*x^2*y -4*x*z^2 +3*x*y, 2*x^3 +x^2*y -2*z^3]; -- zero dim! ApproxSolve(L);
History
#1
Updated by John Abbott almost 6 years ago
Updated by - Status changed from New to In Progress
- % Done changed from 0 to 10
Something odd must have happened: ApproxSolve is failing on almost trivial examples.
Here are some simpler failing examples:
ideal(-2*x*y^2 +2*x^2 +3*x*y, -3*y^3 -2*x^2);
ideal(-x^2 +3*x*y -y, -3*y^2 +x)
Maybe there is a problem when (0,0) is a solution?
#2
Updated by John Abbott almost 6 years ago
It even fails in a univariate case... -3*x^2+2*x.
Investigating...
#3
Updated by John Abbott almost 6 years ago
Here is a surprise:
RealRoots(x); --> gives error log(0)
Ulrich has the version from Jan 2018, and his works...
So I must have made a recent change... sigh!
#4
Updated by John Abbott almost 6 years ago
- Status changed from In Progress to Feedback
- Assignee set to John Abbott
- % Done changed from 10 to 90
The problem was caused by a new better impl of RootBound which can return zero (if arg is just x); the old RootBound could not do this.
Fixed.
#5
Updated by John Abbott over 5 years ago
- Status changed from Feedback to Closed
- % Done changed from 90 to 100
- Estimated time set to 0.77 h
Closing