Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?largv
Generates a vector of plane rotations with real cosines and real/complex sines.
Syntax
call slargv ( n , x , incx , y , incy , c , incc )
call dlargv ( n , x , incx , y , incy , c , incc )
call clargv ( n , x , incx , y , incy , c , incc )
call zlargv ( n , x , incx , y , incy , c , incc )
Include Files
mkl.fi
Description
slargv dlargv clargv zlargv
The routine generates a vector of real/complex plane rotations with real cosines, determined by elements of the real/complex vectors x and y .
For slargv / dlargv :
For clargv / zlargv :
where c(i)^{2} + abs(s(i))^{2} = 1 and the following conventions are used (these are the same as in clartg / zlartg but differ from the BLAS Level 1 routine crotg / zrotg ):
If y_{i} = 0 , then c(i) = 1 and s(i) = 0 ;
If x_{i} = 0 , then c(i) = 0 and s(i) is chosen so that ri is real.
Input Parameters
- n
-
INTEGER . The number of plane rotations to be generated.
- x , y
-
REAL for slargv DOUBLE PRECISION for dlargv COMPLEX for clargv DOUBLE COMPLEX for zlargv Arrays, DIMENSION (1+( n -1)* incx ) and (1+( n -1)* incy ), respectively. On entry, the vectors x and y .
- incx
-
INTEGER . The increment between elements of x . incx > 0 .
- incy
-
INTEGER . The increment between elements of y . incy > 0 .
- incc
-
INTEGER . The increment between elements of the output array c . incc > 0 .
Output Parameters
- x
-
On exit, x(i) is overwritten by ai (for real flavors), or by ri (for complex flavors), for i = 1,...,n .
- y
-
On exit, the sines s(i) of the plane rotations.
- c
-
REAL for slargv / clargv DOUBLE PRECISION for dlargv / zlargv Array, DIMENSION (1+( n -1)* incc ). The cosines of the plane rotations.