Eigenvector output frequency

Eigenvector output frequency = <integer>

Description/Usage

This optional card is used by LOCA to determine how often to write out a set of eigenvectors from the ARPACK eigensolver to EXODUS II files during a continuation problem. When this value is selected to n, ARPACK eigenvectors will be written on the first continuation step and every nth step thereafter. n can also be set to -1, in which case eigenvectors will be output only on the last continuation step.

The default value is -1, in which case eigenvectors are written on every continuation step.

Examples

Here is a sample card:

Eigenvector output frequency = 2

Technical Discussion

This card is useful for continuation problems when is is not desired to save eigenvectors at every continuation step, thus enabling savings of time and disk space.

This value is independent of the Eigenvalue output frequency, so if a frequency m is specified for eigenvalues and n is not a multiple of m, then eigenvectors will be written on step numbers which are common multiples of m and n.

When requesting linear stability analysis during a LOCA continuation run, the eigenvectors from all continuation steps corresponding to a given mode number (or mode number/wave number combination for 3D of 2D) will be written sequentially to the same EXODUS II file. The time stamp for each step will be the eigenvalue, rather than the continuation parameter value. Complex eigenvectors are written as two steps in the same file: first the real part (time-stamped with the real part of the eigenvalue), then the imaginary part (time-stamped with the imaginary part of the eigenvalue).

This card is not applicable to the eggroll eigensolver, which cannot be used during continuation.

Theory

No Theory.

FAQs

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References

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