I am using scipy in a time variable flow model. The matrix pattern does not change over time, so the matrix reordering does not need to be recalculated each timestep. SuperLU supports this with the Fact=SamePattern option - can it be done using the python interface - if so please give an example. Thanks John John Floyd Water, Wetlands and Coasts Science Office of Environment and Heritage Department of Premier and Cabinet john.floyd@environment.nsw.gov.au <mailto:e@environment.nsw.gov.au> Ph: 02-9995-5656 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- This email is intended for the addressee(s) named and may contain confidential and/or privileged information. If you are not the intended recipient, please notify the sender and then delete it immediately. Any views expressed in this email are those of the individual sender except where the sender expressly and with authority states them to be the views of the Office of Environment and Heritage, NSW Department of Premier and Cabinet. PLEASE CONSIDER THE ENVIRONMENT BEFORE PRINTING THIS EMAIL