- naginterfaces.library.blas.zrotgc(a, b)¶
zrotgcgenerates a complex Givens plane rotation having real cosine.
For full information please refer to the NAG Library document for f06ca
The value , the first element of the vector which determines the rotation.
The value , the second element of the vector which determines the rotation.
The value .
The value , the tangent of the rotation.
The value , the cosine of the rotation.
The value , the sine of the rotation.
No equivalent traditional C interface for this routine exists in the NAG Library.
zrotgcgenerates a complex Givens plane rotation with parameters (real ) and (complex), such that, given complex and :
If is real, then is also real. On exit, is overwritten by , the tangent of the rotation; and can be reconstructed from the single stored value , by a subsequent call to
If , where is the machine precision, the function sets and .
Note that is always set to , unless overflow would occur, in which case the function returns the value of the complex expression
is the float value given by .