Given two matrices G and H, the matrix K = [G, 0; 0, H] has determinant det(K) = det(G) det(H) So if you want this formula to remain true if one of the matrices is 0x0, then you want the determinant of a 0x0 matrix to be 1.
________________________________ From: sage-devel@googlegroups.com [sage-devel@googlegroups.com] on behalf of Travis Scrimshaw [tsc...@ucdavis.edu] Sent: Friday, March 18, 2016 10:31 PM To: sage-devel Subject: [sage-devel] What is the determinant of a 0x0 matrix Hey all, We ended up needing to compute the determinant of a 0x0 matrix in #17030.Sage currently says the following: sage: mat = matrix(ZZ, 0, 0) sage: mat.det() 1 However, the code (and myself) was expecting this to be 0 as the sum in the definition is vacuous. Although, in a sense, the 0x0 matrix is its own inverse, so this might be an argument for having it be 1. Thoughts? Best, Travis -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com<mailto:sage-devel+unsubscr...@googlegroups.com>. To post to this group, send email to sage-devel@googlegroups.com<mailto:sage-devel@googlegroups.com>. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
