Developer Reference for Intel® oneAPI Math Kernel Library for C
p?lacon
Estimates the 1-norm of a square matrix, using the reverse communication for evaluating matrix-vector products.
Syntax
voidpslacon ( MKL_INT*n , float*v , MKL_INT*iv , MKL_INT*jv , MKL_INT*descv , float*x , MKL_INT*ix , MKL_INT*jx , MKL_INT*descx , MKL_INT*isgn , float*est , MKL_INT*kase );
voidpdlacon ( MKL_INT*n , double*v , MKL_INT*iv , MKL_INT*jv , MKL_INT*descv , double*x , MKL_INT*ix , MKL_INT*jx , MKL_INT*descx , MKL_INT*isgn , double*est , MKL_INT*kase );
voidpclacon ( MKL_INT*n , MKL_Complex8*v , MKL_INT*iv , MKL_INT*jv , MKL_INT*descv , MKL_Complex8*x , MKL_INT*ix , MKL_INT*jx , MKL_INT*descx , float*est , MKL_INT*kase );
voidpzlacon ( MKL_INT*n , MKL_Complex16*v , MKL_INT*iv , MKL_INT*jv , MKL_INT*descv , MKL_Complex16*x , MKL_INT*ix , MKL_INT*jx , MKL_INT*descx , double*est , MKL_INT*kase );
Include Files
mkl_scalapack.h
Description
pslacon pdlacon pclacon pzlacon The p?lacon routine function estimates the 1-norm of a square, real/unitary distributed matrix A . Reverse communication is used for evaluating matrix-vector products. x and v are aligned with the distributed matrix A , this information is implicitly contained within iv , ix , descv , and descx .
Input Parameters
n
(global) The length of the distributed vectors v and x. n ≥ 0.
- v
-
(local). REAL for pslacon DOUBLE PRECISION for pdlacon COMPLEX for pclacon COMPLEX*16 for pzlacon. Pointer into the local memory to an array of size LOCr ( n +mod( iv -1, mb_v )). On the final return, v = a*w , where est = norm( v )/norm( w ) ( w is not returned).
iv , jv
(global) The row and column indices in the global matrix V indicating the first row and the first column of the submatrix V , respectively.
descv
(global and local) array of size dlen_ . The array descriptor for the distributed matrix V.
- x
-
(local). REAL for pslacon DOUBLE PRECISION for pdlacon COMPLEX for pclacon COMPLEX*16 for pzlacon. Pointer into the local memory to an array of size LOCr ( n +mod( ix -1, mb_x )).
ix , jx
(global) The row and column indices in the global matrix X indicating the first row and the first column of the submatrix X , respectively.
descx
(global and local) array of size dlen_ . The array descriptor for the distributed matrix X.
isgn
(local).
Array of size LOCr ( n +mod( ix -1, mb_x )). isgn is aligned with x and v .
kase
(local).
On the initial call to p?lacon , kase should be 0.
Output Parameters
- x
-
(local). On an intermediate return, X should be overwritten by A * X , if kase =1, A' * X , if kase =2, p?lacon must be re-called with all the other parameters unchanged.
est
(global).
DOUBLE PRECISION for double precision flavors
- kase
-
(local)
On an intermediate return, kase is 1 or 2, indicating whether X should be overwritten by A*X, or A'*X . On the final return from p?lacon , kase is again 0.