dpb
Posts:
8,231
Registered:
6/7/07


Re: data extraction from matrix to use in another matrix
Posted:
Oct 20, 2013 10:45 AM


On 10/19/2013 6:42 PM, walter Mulvany wrote: > My mistake, that matrix is wrong. > I tried what you suggested but I could not get it to work. > here is how the final matrix should look like. > Number of elements? > Elem # Node(a) Node(b) > 1 1 2 > 2 2 3 > 3 3 4 ... > 10 5 6 > 11 6 7 > > Node # X Y > 1 0 0 > 2 2 0 > 3 4 0 ... > 7 5 1 > > Final global matrix > Elem # Nodea Nodeb Nodeax Nodeay > 1 1 2 0 0 > 2 2 3 2 0 > 3 3 4 4 0 ... > 11 6 7 3 1 > > each element has a node(a) and (b), each node(a) have a x and a y > coordinate, but some elements repeat the same node (a). As I said, I'm > very new at Matlab and don't have experience programming. > Can you show me how to type it correctly so that it works? ...
Sure...using just the last two columns for the node/conn matrices (there's no sense in storing a linear index as well; you can generate it for display easily enough), then the result M is simply given by
>> M=zeros(length(conn),4); % preallocate (don't store the index) >> for i=1:length(conn), M(i,:)=[conn(i,:) node(conn(i,1),:)]; end >> M M = 1 2 0 0 2 3 2 0 3 4 4 0 4 7 6 0 3 7 4 0 3 6 4 0 6 2 3 1 5 2 1 1 1 5 0 0 5 6 1 1 6 7 3 1 >>


