C ________________________________________________________ C | | C | MULTIPLY A REAL HESSENBERG MATRIX BY A VECTOR | C | | C | INPUT: | C | | C | X --VECTOR | C | | C | A --ARRAY WITH COEFFICIENT MATRIX PACKED AT | C | START | C | | C | N --DIMENSION OF MATRIX | C | | C | OUTPUT: | C | | C | Y --PRODUCT BETWEEN A AND X | C |________________________________________________________| C SUBROUTINE EMULT(Y,X,A,N) REAL A(1),X(1),Y(1),T INTEGER I,J,K,N IF ( N .GT. 1 ) GOTO 10 Y(1) = A(1)*X(1) RETURN 10 Y(1) = 0. J = 0 K = 1 20 T = X(K) DO 30 I = 1,K 30 Y(I) = Y(I) + T*A(I+J) IF ( K .EQ. N ) RETURN K = K + 1 J = J + K Y(K) = T*A(J) GOTO 20 END