From webb@groucho.csl.uiuc.edu Fri Mar 8 16:38:35 1991 Received: from watmath.waterloo.edu by orion.waterloo.edu with SMTP id ; Fri, 8 Mar 91 16:38:31 EST Received: from surfer.EPM.ORNL.GOV by watmath.waterloo.edu with SMTP id ; Fri, 8 Mar 91 16:38:23 EST Received: by surfer.EPM.ORNL.GOV (5.61/1.34) id AA10786; Fri, 8 Mar 91 16:38:12 -0500 Received: from patience.Stanford.EDU by surfer.EPM.ORNL.GOV (5.61/1.34) id AA10776; Fri, 8 Mar 91 16:37:43 -0500 Received: from groucho.csl.uiuc.edu by patience.Stanford.EDU (4.0/inc-1.5) id AA03771; Fri, 8 Mar 91 13:37:49 PST Message-Id: <9103082137.AA03771@patience.Stanford.EDU> Received: by groucho.csl.uiuc.edu (15.11/15.6) id AA08087; Fri, 8 Mar 91 15:35:38 cst From: Jennifer Webb Subject: bugs in simplex matlab routine from netlib To: na.wolkowicz@patience.Stanford.EDU Date: Fri, 8 Mar 91 15:35:35 CST Mailer: Elm [revision: 64.9] Status: RO I have been using the simplex1 m-files which you wrote, having obtained them through netlib. They have been a tremendous help! However, I believe that my test cases have uncovered two errors in the loop following the comment "Ensure that no artificial variable remains in the basis" in main.m. First of all, in order to avoid inconsistent array dimensions later on, (c=c-ap(i,:)*ratio computation), I added a line immediately before the "Ensure..." comment: c=c(1:n1+m1); The other change was in adding an absolute value to the "%pivot column" line, ie. t=n1m1to1(abs(a(i,:))>eps1); Thank you again for the use of your routine. Sincerely, Jennifer Webb