ZUNGL2(3) LAPACK routine of NEC Numeric Library Collection ZUNGL2(3) NAME ZUNGL2 SYNOPSIS SUBROUTINE ZUNGL2 (M, N, K, A, LDA, TAU, WORK, INFO) PURPOSE ZUNGL2 generates an m-by-n complex matrix Q with orthonormal rows, which is defined as the first m rows of a product of k elementary reflectors of order n Q = H(k)**H . . . H(2)**H H(1)**H as returned by ZGELQF. ARGUMENTS M (input) M is INTEGER The number of rows of the matrix Q. M >= 0. N (input) N is INTEGER The number of columns of the matrix Q. N >= M. K (input) K is INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0. A (input/output) A is COMPLEX*16 array, dimension (LDA,N) On entry, the i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGELQF in the first k rows of its array argument A. On exit, the m by n matrix Q. LDA (input) LDA is INTEGER The first dimension of the array A. LDA >= max(1,M). TAU (input) TAU is COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGELQF. WORK (output) WORK is COMPLEX*16 array, dimension (M) INFO (output) INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value LAPACK routine 31 October 2017 ZUNGL2(3)