*DECK OHTROL SUBROUTINE OHTROL (Q, N, NRDA, DIAG, IRANK, DIV, TD) C***BEGIN PROLOGUE OHTROL C***SUBSIDIARY C***PURPOSE Subsidiary to BVSUP C***LIBRARY SLATEC C***TYPE SINGLE PRECISION (OHTROL-S, DOHTRL-D) C***AUTHOR Watts, H. A., (SNLA) C***DESCRIPTION C C For a rank deficient problem, additional orthogonal C HOUSEHOLDER transformations are applied to the left side C of Q to further reduce the triangular form. C Thus, after application of the routines ORTHOR and OHTROL C to the original matrix, the result is a nonsingular C triangular matrix while the remainder of the matrix C has been zeroed out. C C***SEE ALSO BVSUP C***ROUTINES CALLED SDOT C***REVISION HISTORY (YYMMDD) C 750601 DATE WRITTEN C 890831 Modified array declarations. (WRB) C 891214 Prologue converted to Version 4.0 format. (BAB) C 900328 Added TYPE section. (WRB) C 910722 Updated AUTHOR section. (ALS) C***END PROLOGUE OHTROL