Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
p?nrm2
Computes the Euclidean norm of a distributed vector.
Syntax
call psnrm2 ( n , norm2 , x , ix , jx , descx , incx )
call pdnrm2 ( n , norm2 , x , ix , jx , descx , incx )
call pscnrm2 ( n , norm2 , x , ix , jx , descx , incx )
call pdznrm2 ( n , norm2 , x , ix , jx , descx , incx )
Include Files
mkl_pblas.h
Description
psnrm2 pdnrm2 pscnrm2 pdznrm2 The p?nrm2 functions compute the Euclidean norm of a distributed vector sub(x) ,
where sub(x) is an n -element distributed vector.
sub(x) denotes X(ix, jx:jx+n-1) if incx=m_x , and X(ix: ix+n-1, jx) if incx= 1 .
Input Parameters
n
(global) INTEGER . The length of distributed vector sub(x) , n ≥ 0.
x
(local) REAL for psnrm2
DOUBLE PRECISION for pdnrm2 COMPLEX for pscnrm2 DOUBLE COMPLEX for pdznrm2 Array, size (jx-1)*m_x + ix+(n-1)*abs(incx)) . This array contains the entries of the distributed vector sub(x) .
ix , jx
(global) INTEGER . The row and column indices in the distributed matrix X indicating the first row and the first column of the submatrix sub(X) , respectively.
descx
(global and local) INTEGER array of dimension 9. The array descriptor of the distributed matrix X .
incx
(global) INTEGER . Specifies the increment for the elements of sub(x) . Only two values are supported, namely 1 and m_x . incx must not be zero.
Output Parameters
norm2
(local) REAL for psnrm2 and pscnrm2 .
DOUBLE PRECISION for pdnrm2 and pdznrm2 Contains the Euclidean norm of a distributed vector only in its scope.