Re: Keeping rational functions simple throughout gaussian elimination

[JamesHDavenport]

I have no idea whether SAGE supports this, but basically what you need is fraction-free Gaussian elimination: See section 3.2.3 of http:/staff.bath.ac.uk/masjhd/JHD-CA.pdf

On Wednesday, 22 August 2012 13:04:08 UTC+1, Erik Aas wrote:

I'm trying to solve a system of linear equations over the field Q(x1,...,xn) of rational functions in x1,...,xn.

The system is Ax = 0 where A has entries from the field and has rather large size (500 rows and columns for example).

One way to do it is to compute kernel(A). In my case it is 1-dimensional. The basis vector returned has coordinates of the form (polynomial/polynomial + polynomial) / (polynomial - polynomial) et.c. Calling .denominator() and .numerator() on the expression does not terminate before my patience does. Is there a way to make sure the equation solver keep all coefficients on the form polynomial / polynomial?