Hi, I have five groups (of genes) with each group having different number of members. What I need to do is to apply a function to a set that contains one gene from each group. I would like to do this for every possible set. For example, Groups 1: 1 2: 5 6 7 3: 2 3 I would like to apply the function to: 1,5,2 1,5,3 1,6,2 1,6,3 1,7,2 1,7,3 This has come up in pathway analysis (gene enrichment analysis) where I want to look at a number of different isoforms of each gene. Does anyone know a way to get these combinations? Thanks Dan -- ************************************************************** Daniel Brewer, Ph.D. Institute of Cancer Research Molecular Carcinogenesis MUCRC 15 Cotswold Road Sutton, Surrey SM2 5NG United Kingdom Tel: +44 (0) 20 8722 4109 Fax: +44 (0) 20 8722 4141 Email: daniel.brewer at icr.ac.uk ************************************************************** The Institute of Cancer Research: Royal Cancer Hospital, a charitable Company Limited by Guarantee, Registered in England under Company No. 534147 with its Registered Office at 123 Old Brompton Road, London SW7 3RP. This e-mail message is confidential and for use by the addre...{{dropped}}

Hi Daniel, try: expand.grid(1, 5:7, 2:3) Regards, Joern Daniel Brewer wrote: > Hi, > > I have five groups (of genes) with each group having different number of > members. What I need to do is to apply a function to a set that > contains one gene from each group. I would like to do this for every > possible set. > > For example, > > Groups > 1: 1 > 2: 5 6 7 > 3: 2 3 > > I would like to apply the function to: > 1,5,2 > 1,5,3 > 1,6,2 > 1,6,3 > 1,7,2 > 1,7,3 > > This has come up in pathway analysis (gene enrichment analysis) where I > want to look at a number of different isoforms of each gene. > > Does anyone know a way to get these combinations? > > Thanks > > Dan > >