C.hr DGMABA C@ C....*...1.........2.........3.........4.........5.........6.........7.* C DGMABA 6/20/87 (ANNIVERSARY) C C PURPOSE C COMPUTE THE QUADRATIC FORM: R = A'BA. C C USAGE C CALL DGMABA(A,B,R,N,M) C C ARGUMENTS C A - INPUT N BY M MATRIX STORED COLUMNWISE (STORAGE MODE 0) C REAL*8 C B - INPUT N BY N MATRIX STORED COLUMNWISE (STORAGE MODE 0) C REAL*8 C R - OUTPUT M BY M MATRIX STORED COLUMNWISE (STORAGE MODE 0) C REAL*8 C N - NUMBER OF ROWS IN A C INTEGER*4 C M - NUMBER OF COLUMNS IN A C INTEGER*4 C SUBROUTINE DGMABA(A,B,R,N,M) implicit real*8 (a-h,o-z) save C REAL*8 A(1),B(1),R(1),ACC REAL*8 A(N*M),B(N*N),R(M*M) DO 20 JJ=1,M DO 20 II=1,JJ ACC=0.D0 DO 10 J=1,N DO 10 I=1,N 10 ACC=ACC+A(N*(JJ-1)+I)*A(N*(II-1)+J)*B(N*(J-1)+I) R(M*(II-1)+JJ)=ACC 20 R(M*(JJ-1)+II)=ACC RETURN END