ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Sun, 10 Dec 2023 23:25:41 +0100How to convert Gram matrix to quadratic form?https://ask.sagemath.org/question/74773/how-to-convert-gram-matrix-to-quadratic-form/How to do the opposite? Given `gm`, how to compute coefficients of quadratic form `qf`?
qf=QuadraticForm(ZZ, 4, [4, -12, 8, -4, 12, -16, 8, 6, -6, 2])
gm=qf.Gram_matrix()
gm
---
[ 4 -6 4 -2]
[-6 12 -8 4]
[ 4 -8 6 -3]
[-2 4 -3 2]azerbajdzanSun, 10 Dec 2023 23:25:41 +0100https://ask.sagemath.org/question/74773/Invertible matrix with integer coefficientshttps://ask.sagemath.org/question/65194/invertible-matrix-with-integer-coefficients/ I try to build an invertable matrix, but using the .inverse() method returns matrix with rational coefs, so is there an opportunity in sage to return the inverse matrix with integer coefficients by taking out a common factor?DreDdSat, 03 Dec 2022 20:43:24 +0100https://ask.sagemath.org/question/65194/Is there a command to compute a *non-reduced* Hermite echelon form of a matrix?https://ask.sagemath.org/question/64138/is-there-a-command-to-compute-a-non-reduced-hermite-echelon-form-of-a-matrix/I'd like to compute a Hermite echelon form of an integer matrix without going all the way to the reduced Hermite normal form. echelon_form(), echelonize(), and hermite_form() all appear to return the reduced version (zeros above the pivots). I could program it myself, but I'm hoping there's an easier way. Thanks!joshuarbholdenThu, 22 Sep 2022 01:08:31 +0200https://ask.sagemath.org/question/64138/