LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
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real function sqrt11 | ( | integer | M, |
integer | K, | ||
real, dimension( lda, * ) | A, | ||
integer | LDA, | ||
real, dimension( * ) | TAU, | ||
real, dimension( lwork ) | WORK, | ||
integer | LWORK | ||
) |
SQRT11
SQRT11 computes the test ratio || Q'*Q - I || / (eps * m) where the orthogonal matrix Q is represented as a product of elementary transformations. Each transformation has the form H(k) = I - tau(k) v(k) v(k)' where tau(k) is stored in TAU(k) and v(k) is an m-vector of the form [ 0 ... 0 1 x(k) ]', where x(k) is a vector of length m-k stored in A(k+1:m,k).
[in] | M | M is INTEGER The number of rows of the matrix A. |
[in] | K | K is INTEGER The number of columns of A whose subdiagonal entries contain information about orthogonal transformations. |
[in] | A | A is REAL array, dimension (LDA,K) The (possibly partial) output of a QR reduction routine. |
[in] | LDA | LDA is INTEGER The leading dimension of the array A. |
[in] | TAU | TAU is REAL array, dimension (K) The scaling factors tau for the elementary transformations as computed by the QR factorization routine. |
[out] | WORK | WORK is REAL array, dimension (LWORK) |
[in] | LWORK | LWORK is INTEGER The length of the array WORK. LWORK >= M*M + M. |
Definition at line 100 of file sqrt11.f.