> I just discovered the following (imho unsatisfactory) behavior of > Matrix.det: > > In <211>: from sympy.abc import a,b,c,d, C > In <212>: M = Matrix([[a+b, 0, cos(c)], [0, d, 0], [cos(c), 0, 1]]) > In <213>: M > Out<213>: > [ a + b, 0, cos(c)] > [ 0, d, 0] > [cos(c), 0, 1] > > In <214>: M.det() > Out<214>: d*a**2/(a + b) + d*b**2/(a + b) + 2*a*b*d/(a + b) - > a*d*cos(c)**2/(a + b) - b*d*cos(c)**2/(a + b) > > I wonder why there are fractions in the result (all the more as in the > docstring of det_bareis one reads, that the algorihtm "will result in a > determinant with minimal number of fractions".).
copyrights has been helping to test the 1766 branch at github/smichr. In that branch I get: >>> from sympy.abc import a,b,c,d, C >>> M = Matrix([[a+b, 0, cos(c)], [0, d, 0], [cos(c), 0, 1]]) >>> M.det() a*d + b*d - d*cos(c)**2 There is also a method for matrices to remove the gcd from termps: >>> M = Matrix([[2*a, 4*a],[3*a, 6*a]]) >>> M.gcdfactor() a >>> M [2, 4] [3, 6] You might give that a try until 1766 is finally merged into master. -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
