12-05-2019, 04:49 AM
Hello, I found this bug calculating the inverse of a matrix in the latest firmware, Have you guys seen it in any previous firmware before?
![[Image: error_inversa%20prime_01.jpg]](http://www.deachp.com/enlazados/error_inversa%20prime_01.jpg)
![[Image: error_inversa%20prime_00.jpg]](http://www.deachp.com/enlazados/error_inversa%20prime_00.jpg)
![[Image: error_inversa%20prime_02.jpg]](http://www.deachp.com/enlazados/error_inversa%20prime_02.jpg)
![[Image: error_inversa%20prime_03.jpg]](http://www.deachp.com/enlazados/error_inversa%20prime_03.jpg)
12-05-2019, 01:16 PM
I forwarded on to the CAS author and it has been corrected. Only looked like it happened due to the approximate number in there.
1/2*s would have worked fine.
1/2*s would have worked fine.
12-05-2019, 01:38 PM
Tried doing inverse by "hand", XCas 1.4.9-57 (win32).
The bug maybe in rref()
BTW, doing inv([[1,0], [0,1/(2.*s)]]) crash XCas.
The bug maybe in rref()
Code:
XCas> m := [[1,0,1,0], [0,1/(2*s),0,1]]
XCas> rref(m) → [[1,0, 1,0] , [0,1, 0,2*s]]
XCas> rref(float(m)) → [[1,0, 2.0*s,0], [0,1, 0,4.0*s^2]] ???BTW, doing inv([[1,0], [0,1/(2.*s)]]) crash XCas.