Subsetting indexed variable?
- To: mathgroup at smc.vnet.net
- Subject: [mg36028] Subsetting indexed variable?
- From: "Gareth J. Russell" <gjr2008 at columbia.edu>
- Date: Tue, 13 Aug 2002 05:22:51 -0400 (EDT)
- Organization: Columbia University
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
I cannot seem to work out how to extract a subset of information from an
indexed variable (without generating a full list/matrix first).
For example, suppose I define:
b[1,3] = 3
b[2,3] = 7
b[2,4] = 5
And I then want to get the list of all DEFINED values of b[2,_], i.e., the
result should be {7,5}
Help appreciated!
Gareth
==========================================================
Dr. Gareth J. Russell
Columbia University
E-mail: gjr2008 at columbia.edu
==========================================================