Matrix Help ```Name: Unknown Status: N/A Age: N/A Location: N/A Country: N/A Date: Around 1993 ``` Question: I am using Lotus 123 for Windows and want to calculate the determinant of a matrix? Has anyone ever written a macro or can help in setting one up? Replies: No, I have never written a Lotus 1-2-3 macro for that purpose, but I have calculated a few determinants numerically in my day. The simplest way I know of is through LU decomposition. Suppose we want the determinant of a matrix X. If we can somehow decompose the matrix into the product of two matrices, i.e., X = L * U, and do it in such a way that L is "lower- triangular" (all non-zero elements on the diagonal and below) and U is "upper- triangular" (all non-zero elements on the diagonal and above), then we can use L and U to get the determinant. This whole procedure is described in detail in a book called: Numerical Recipes by W.H. Press, B.P. Flannery, S.A. Teukolsky, and W.T. Vetterling (Cambridge Press, Cambridge, 1986). It should be in the library of your local university/college. Hope this has been helpful. Topper Click here to return to the Mathematics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs