(S|D|C|Z)LARTG¶

Single, double, single complex, and double complex LARTG.

Description¶

Generates a plane rotation such that:

$\left[ \begin{matrix} \fvar{CS} & \fvar{SN} \\ -\sconj{\fvar{SN}} & \fvar{CS} \\ \end{matrix} \right] \mult \left[ \begin{matrix} \fvar{F} \\ \fvar{G} \end{matrix} \right] = \left[ \begin{matrix} \fvar{R} \\ 0 \end{matrix} \right]$

where $\fvar{CS}^2+|\fvar{SN}|^2 = 1$ .

LAPACK Interface¶

void slartg(const float *F, const float *G, float *CS, float *SN, float *R);

void dlartg(const double *F, const double *G, double *CS, double *SN, double *R);

void clartg(const qml_single_complex *F, const qml_single_complex *G,
    float *CS, qml_single_complex *SN, qml_single_complex *R);

void zlartg(const qml_double_complex *F, const qml_double_complex *G,
    double *CS, qml_double_complex *SN, qml_double_complex *R);

Arguments¶

F	First part of vector to rotate
G	Second part of vector to rotate
CS	Cosine part of rotation matrix
SN	Sine part of rotatione matrix
R	Residual after rotation