That command is in package MASS. Use commands Install.packages("MASS") to install it from CRAN, then Library(MASS) to load it in R session. Now you have the command available Dmitriy ------------------------------ *From:* gov2001-l-bounces at lists.fas.harvard.edu [mailto: gov2001-l-bounces at lists.fas.harvard.edu] *On Behalf Of *Jeremy Hodgen *Sent:* Wednesday, February 20, 2008 4:33 AM *To:* gov2001-l at lists.fas.harvard.edu *Subject:* [gov2001-l] Matrix manipulation Can anyone help? I'm trying to generate the inverse of a matrix but when I use ginv I get an error message: Error: could not find function "ginv" Am I doing something stupid? Jeremy Dr Jeremy Hodgen Senior Lecturer in Mathematics Education King's College London Department of Education and Professional Studies Franklin-Wilkins Building Waterloo Bridge Wing 150 Stamford Street London SE1 9NH Tel: 020 7848 3102 Fax: 020 7848 3182 E-mail: jeremy.hodgen at kcl.ac.uk __________ NOD32 2887 (20080219) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com _______________________________________________ gov2001-l mailing list gov2001-l at lists.fas.harvard.edu http://lists.fas.harvard.edu/mailman/listinfo/gov2001-l