On Tue, Dec 30, 2014 at 8:45 PM, Dan Drake <ddr...@math.wisc.edu> wrote: > Hi, > > I'm teaching linear algebra and would like to automatically get a list > of the row operations one can use to put a matrix into reduced row > echelon form. So I coded up the usual algorithm: > > https://gist.github.com/dandrake/6fa2f03b5dff632706a9 > > You can get a list of elementary matrices or a list of strings that > describe what one does: > > sage: A > [ 1 2 0 -2 0] > [ 1 -2 1 -2 0] > [-1 0 0 -2 0] > sage: rref_steps(A) > ['add $-1$ times row 1 to row 2', > 'add $1$ times row 1 to row 3', > 'scale row 2 by $-1/4$', > 'add $-2$ times row 2 to row 1', > 'add $-2$ times row 2 to row 3', > 'scale row 3 by $2$', > 'add $-1/2$ times row 3 to row 1', > 'add $1/4$ times row 3 to row 2'] > sage: prod(rref(A)) * A == A.rref() > True >
Very useful, thanks! > > Just sharing. Enjoy. > > Dan > > -- > --- Dan Drake > ----- www.math.wisc.edu/~ddrake/ > ------- > > -- > You received this message because you are subscribed to the Google Groups > "sage-edu" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-edu+unsubscr...@googlegroups.com. > To post to this group, send email to sage-edu@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-edu. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-edu" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-edu+unsubscr...@googlegroups.com. To post to this group, send email to sage-edu@googlegroups.com. Visit this group at http://groups.google.com/group/sage-edu. For more options, visit https://groups.google.com/d/optout.
