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
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.