LAESY: computes the eigendecomposition of a 2-by-2 symmetric matrix ( ( A, B );( B, C ) ) provided the norm of the matrix of eigenvectors is larger than some threshold value. RT1 is the eigenvalue of larger absolute value, and RT2 of smaller absolute value. If the eigenvectors are computed, then on return ( CS1, SN1 ) is the unit eigenvector for RT1, hence [ CS1 SN1 ] . [ A B ] . [ CS1 -SN1 ] = [ RT1 0 ] [ -SN1 CS1 ] [ B C ] [ SN1 CS1 ] [ 0 RT2 ].
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| pure subroutine | claesy (a, b, c, rt1, rt2, evscal, cs1, sn1) |
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| | la_claesy |
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| | la_wlaesy |
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| pure subroutine | zlaesy (a, b, c, rt1, rt2, evscal, cs1, sn1) |
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| | la_zlaesy |
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LAESY: computes the eigendecomposition of a 2-by-2 symmetric matrix ( ( A, B );( B, C ) ) provided the norm of the matrix of eigenvectors is larger than some threshold value. RT1 is the eigenvalue of larger absolute value, and RT2 of smaller absolute value. If the eigenvectors are computed, then on return ( CS1, SN1 ) is the unit eigenvector for RT1, hence [ CS1 SN1 ] . [ A B ] . [ CS1 -SN1 ] = [ RT1 0 ] [ -SN1 CS1 ] [ B C ] [ SN1 CS1 ] [ 0 RT2 ].
◆ claesy()
| pure subroutine la_lapack::laesy::claesy |
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complex(sp), intent(in) | a, |
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complex(sp), intent(in) | b, |
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complex(sp), intent(in) | c, |
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complex(sp), intent(out) | rt1, |
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complex(sp), intent(out) | rt2, |
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complex(sp), intent(out) | evscal, |
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complex(sp), intent(out) | cs1, |
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complex(sp), intent(out) | sn1 ) |
◆ la_claesy()
| la_lapack::laesy::la_claesy |
◆ la_wlaesy()
| la_lapack::laesy::la_wlaesy |
◆ la_zlaesy()
| la_lapack::laesy::la_zlaesy |
◆ zlaesy()
| pure subroutine la_lapack::laesy::zlaesy |
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complex(dp), intent(in) | a, |
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complex(dp), intent(in) | b, |
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complex(dp), intent(in) | c, |
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complex(dp), intent(out) | rt1, |
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complex(dp), intent(out) | rt2, |
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complex(dp), intent(out) | evscal, |
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complex(dp), intent(out) | cs1, |
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complex(dp), intent(out) | sn1 ) |
The documentation for this interface was generated from the following file:
