?orbdb6/?unbdb6

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 4/28/2026

Version

Public

Orthogonalizes a column vector with respect to the orthonormal basis matrix.

call sorbdb6 ( m1 , m2 , n , x1 , incx1 , x2 , incx2 , q1 , ldq1 , q2 , ldq2 , work , lwork , info )

call dorbdb6 ( m1 , m2 , n , x1 , incx1 , x2 , incx2 , q1 , ldq1 , q2 , ldq2 , work , lwork , info )

call cunbdb6 ( m1 , m2 , n , x1 , incx1 , x2 , incx2 , q1 , ldq1 , q2 , ldq2 , work , lwork , info )

call zunbdb6 ( m1 , m2 , n , x1 , incx1 , x2 , incx2 , q1 , ldq1 , q2 , ldq2 , work , lwork , info )

The ?orbdb6 / ?unbdb6 routines orthogonalize the column vector

with respect to the columns of

The columns of Q must be orthonormal.

If the projection is zero according to Kahan’s “twice is enough” criterion, then the zero vector is returned.

m1: INTEGER The dimension of x1 and the number of rows in q1 . 0 ≤ m1 .
m2: INTEGER The dimension of x2 and the number of rows in q2 . 0 ≤ m2 .
n: INTEGER The number of columns in q1 and q2 . 0 ≤ n .
x1: REAL for sordb5 DOUBLE PRECISION for dordb5 COMPLEX for cundb5 COMPLEX*16 for zundb5 Array of size m1 . The top part of the vector to be orthogonalized.
incx1: INTEGER Increment for entries of x1 .
x2: REAL for sordb5 DOUBLE PRECISION for dordb5 COMPLEX for cundb5 COMPLEX*16 for zundb5 Array of size m2 . The bottom part of the vector to be orthogonalized.
incx2: INTEGER Increment for entries of x2 .
q1: REAL for sordb5 DOUBLE PRECISION for dordb5 COMPLEX for cundb5 COMPLEX*16 for zundb5 Array of size ( ldq1 , n ). The top part of the orthonormal basis matrix.
ldq1: INTEGER The leading dimension of q1 . ldq1 ≥ m1 .
q2: REAL for sordb5 DOUBLE PRECISION for dordb5 COMPLEX for cundb5 COMPLEX*16 for zundb5 Array of size ( ldq2 , n ). The bottom part of the orthonormal basis matrix.
ldq2: INTEGER The leading dimension of q2 . ldq2 ≥ m2 .
work: REAL for sordb5 DOUBLE PRECISION for dordb5 COMPLEX for cundb5 COMPLEX*16 for zundb5 Workspace array of size lwork .
lwork: INTEGER The size of the array work . lwork ≥ n .

info

INTEGER .

NOTE: