## accessing matrix value

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hgpillai
Posts: 7
Joined: Wed Jan 11, 2006 6:08 pm

### accessing matrix value

Hi, One of the input of my submodel is a 3*3 matrix, How do I access the elements individually ( say for example 2nd row, 2nd column value) in the code?

Johan
Posts: 19
Joined: Mon Sep 19, 2005 2:34 pm
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### Re: accessing matrix value

hgpillai wrote:Hi, One of the input of my submodel is a 3*3 matrix, How do I access the elements individually ( say for example 2nd row, 2nd column value) in the code?
This can be done as follows:

See also the help file: chapter "language reference" and sub chapter "Matrices and vectors".

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``````L[4] = time; // Make element 4 of columned L equal to time.

D[2,5] = A[2,2]*B[1,1]; // Declare one element``````
Multiple elements (ranges)
To prevent multiple equations for assigning matrix elements, ranges can be assigned using a colon. E.g. 1:5 means element 1 to 5, 7:8 means element 7 and 8. Backward counting ranges (like 10:1) are not allowed!

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``D[2,1:5] = A[1,1:5]; // D[2,1] = A[1,1], ... , D[2,5] = A[1,5]``

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``````variables

real v[3],p[6,6];

equations

v = p[4:6,6]; // v[1] = p[4,6], ... , v[3] = p[6,6]``````
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