Setting up a matrix from input file?

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PSU
PSU on 5 Oct 2014
Commented: PSU on 5 Oct 2014
I have a file that has 7 nodes and 8 elements that I am retrieving data from.
I am currently trying to set-up a stiffness matrix but I am struggling with coming up with the correct code to build my matrix.
Below is the format from my .inp file. The first row is the number of the element and the other two columns are were the nodes are connected at. So in other words element 1 is connected at nodes 1 and 7.
if true
% code
end
1 1 7
2 3 5
3 7 6
4 4 6
5 4 1
6 4 2
7 5 7
8 2 5
I got it to read each column by calling each column N1, N2, N3 but then when I do A=[N1; N2; N3]
it gives me:
if true
% code
end
A =
1
2
3
4
5
6
7
8
1
3
7
4
4
4
5
2
7
5
6
6
1
2
7
5
Please Help
Thank you!

Accepted Answer

Image Analyst
Image Analyst on 5 Oct 2014
Using a semicolon puts the matrices one atop the other (vertical concatenation). Using a comma puts them side by side (horizontal concatenation). Try this
A=[N1, N2, N3]
Or just read it into A directly with dlmread() or readtable().
A = dlmread(filename, ' ');

More Answers (1)

Azzi Abdelmalek
Azzi Abdelmalek on 5 Oct 2014
A=[N1 N2 N3]

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