Re: Direct Memory Replacing in Array
- To: mathgroup at smc.vnet.net
- Subject: [mg46835] Re: Direct Memory Replacing in Array
- From: "Mariusz Jankowski" <mjankowski at usm.maine.edu>
- Date: Tue, 9 Mar 2004 19:57:49 -0500 (EST)
- Organization: University of Southern Maine
- References: <c2k4q5$qq0$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Jeremy, use mat[[i,j]] = new; See Part for details. Mariusz >>> Jeremy Fox<jeremytfox at yahoo.com> 3/9/2004 5:03:49 AM >>> The Mathematica syntax mat = ReplacePart[mat,new,index] is clean. However, it probably involves a complete replacing of the entire, old mat with the entire new mat, in memory. This operation is expensive if the user is interested in changing only a small part of a large array mat. Is there a way to change small numbers of elements in an array without requiring the other elements to be copied again? This is how low-level languages such a C and Fortran work. Jeremy