What is the importance or function of the condition number?

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

What is the importance or function of the condition number?

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Answers

  • JIF
    JIF
    Altair Employee
    edited June 2017

    The condition number refers to the level of linear independence of the matrix equations. A low condition number indicates that the matrix can be solved with high accuracy and vice versa. Users need not be concerned about this property unless FEKO issues a warning.

    When FEKO gives a warning about the condition number, it is possible that in some cases the results obtained are not very accurate. For example, when very low field values are being calculated (for instance the back lobe of an antenna's radiation pattern or very low coupling values such as S-parameters), users should take caution.

    Conversely, if the gain of an antenna in the main lobe of the radiation pattern is the relevant property, it is more likely that accuracy is not compromised as easily with a high condition number.

    High condition numbers are typically obtained for electrically small, yet geometrically complex geometries where the mesh size is typically much smaller than the meshing guidelines provided.

    As a remedy, users can switch to double precision. If a warning is still given for the condition number, the low frequency stabilisation for the MoM can be activated. Low frequency stabilisation will cause an increase in runtime.