p?max1

Developer Reference for Intel® oneAPI Math Kernel Library for C

Download PDF

ID 766684

Date 4/28/2026

Version

Public

p?max1

Finds the index of the element whose real part has maximum absolute value (similar to the Level 1 PBLAS p?amax , but using the absolute value to the real part).

Syntax

voidpcmax1 ( MKL_INT*n , MKL_Complex8*amax , MKL_INT*indx , MKL_Complex8*x , MKL_INT*ix , MKL_INT*jx , MKL_INT*descx , MKL_INT*incx );

voidpzmax1 ( MKL_INT*n , MKL_Complex16*amax , MKL_INT*indx , MKL_Complex16*x , MKL_INT*ix , MKL_INT*jx , MKL_INT*descx , MKL_INT*incx );

Include Files

mkl_scalapack.h

Description

pcmax1 pzmax1 The p?max1 routine function computes the global index of the maximum element in absolute value of a distributed vector sub( X ). The global index is returned in indx and the value is returned in amax , where sub( X ) denotes X(ix:ix+n-1, jx) if incx = 1 , X(ix, jx:jx+n-1) if incx = m_x .

Input Parameters

n

(global) . The number of components of the distributed vector sub( X ). n ≥ 0.

x

(local) COMPLEX for pcmax1 . COMPLEX*16 for pzmax1

Pointer into the local memory to an array of size lld_x * LOCc ( jx + n -1) . On entry this array contains the local pieces of the distributed vector sub( X ).

ix

(global) The row index in the global matrix X indicating the first row of sub( X ).

jx

(global) The column index in the global matrix X indicating the first column of sub( X ).

descx

(global and local) Array of size dlen_ . The array descriptor for the distributed matrix X .

incx

(global) .The global increment for the elements of X . Only two values of incx are supported in this version, namely 1 and m_x . incx must not be zero.

Output Parameters

amax

(global output) .The absolute value of the largest entry of the distributed vector sub( X ) only in the scope of sub( X ).

indx

(global output) .The global index of the element of the distributed vector sub( X ) whose real part has maximum absolute value.

NOTE:

Overview

Select Your Language

Using Intel.com Search

Quick Links

Recent Searches

Advanced Search

Only search in

Developer Reference for Intel® oneAPI Math Kernel Library for C

p?max1

Syntax

Include Files

Description

Input Parameters

Output Parameters