Mass Matrix

[stoykov]

Hello Elmer users,

I think if someone needs to have the mass and the stiffness matrices, they can be accessed through the pointer Matrix_t:

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TYPE(Matrix_t), POINTER :: A
A => Solver % Matrix
A % BulkValues    ! pointer to the values of the stiffness matrix
A % MassValues  ! pointer to the values of the mass matrix

How to access the values by rows and columns is explained in section 3.6.1 from ElmerSolver Manual.

The code

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Dump System Matrix = String "matrix"

write the values from

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A % Values

which is not exactly the stiffness matrix. Can someone explain the difference between A % BulkValues and A % Values, for example in an eigenvalue problem?

Regrds,
Stan

[raback]

Hi

BulkValues are Values prior to setting the BCs for the linear system Ax=b. The BulkValues may be used to 1) speed up assembly and 2) to calculate the effect of BCs in the "Calculate Loads" keyword. BulkValues are computed only if either of 1) and 2) is active.

-Peter