2016-07-04 18:17:02 +0200 | commented question | Wrong determinant of matrix based on multivariate polynomial ring If I change the ring RDF to RR, the result is which is also wrong (and interestingly differently wrong). To me it seems that there is a bug in Sage. Should a "bug ticket" posted in another forum? |
2016-07-02 21:13:38 +0200 | asked a question | Wrong determinant of matrix based on multivariate polynomial ring Hello everybody, I have a problem with determinants of matrices based on multivariate polynomial rings. I have tried tor reduce the problem to the follwing small code snippet. When I input the following code: The result is This is completely wrong. The matrix X contains small flouting point precision error, which however should not prodcue the above result. Due to my original problem I used a polynomial ring with two variables, which seems to be the source of the problem. For example, when in the above code I use which is the correct result (up to precision errors). By the way, the correct result without precision errors is Anybody knows what is going wrong? Thank you in advance. By the way, I am using the Standard Windows Sage 7.0 Binary: "sage-7.0.ova". |
2016-07-02 21:13:37 +0200 | asked a question | Float error by determinate of mulitvariate polynomial Hello, I have a problem with determinants of matrices based on multivariate polynomial rings. I have tried tor reduce the problem to the follwing small code snippet. When I input the following code: The result is This is completely wrong. The matrix X contains small flouting point precision error, which however should not prodcue the above result. Due to my original problem is used a polynomial ring with two variables, which seems to be the source of the problem. For example, when in the above code I use "R.<x> = PolynomialRing(RDF)", i.e. a polynomial ring with only one variable, the result is which is the correct result (up to precision errors). By the way, the correct result without precision errors is Anybody knows what is going wrong? Thank you in advance. |