naginterfaces.library.blas.deig2

naginterfaces.library.blas.deig2(a, b, c)[source]

deig2 returns an eigenvalue of a real symmetric matrix.

For full information please refer to the NAG Library document for f06bp

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06bpf.html

Parameters
afloat

The value , the element of the input matrix.

bfloat

The value , the or element of the input matrix.

cfloat

The value , the element of the input matrix.

Returns
evfloat

The eigenvalue.

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

deig2 returns an eigenvalue of the real symmetric matrix

The result is intended for use as a shift in symmetric eigenvalue functions.

The eigenvalue is computed as

where .

This is the eigenvalue nearer to if , and is equal to if .