DECLARE SUB LUDCMP (A!(), N!, NP!, INDX!(), D!)
DECLARE SUB LUBKSB (A!(), N!, NP!, INDX!(), B!())
DECLARE SUB MPROVE (A!(), ALUD!(), N!, NP!, INDX!(), B!(), X!())
DECLARE FUNCTION RAN3! (IDUM&)

'PROGRAM D2R5
'Driver for routine MPROVE
CLS
N = 5
NP = 5
DIM A(NP, NP), INDX(N), B(N), X(N), AA(NP, NP)
FOR J = 1 TO NP
  FOR I = 1 TO NP
    READ A(I, J)
  NEXT I
NEXT J
DATA 1.0,2.0,1.0,4.0,5.0,2.0,3.0,1.0,5.0,1.0,3.0,4.0,1.0,1.0,2.0,4.0,5.0,1.0
DATA 2.0,3.0,5.0,1.0,1.0,3.0,4.0
FOR I = 1 TO N
  READ B(I)
NEXT I
DATA 1.0,1.0,1.0,1.0,1.0
FOR I = 1 TO N
  X(I) = B(I)
  FOR J = 1 TO N
    AA(I, J) = A(I, J)
  NEXT J
NEXT I
CALL LUDCMP(AA(), N, NP, INDX(), D)
CALL LUBKSB(AA(), N, NP, INDX(), X())
PRINT "Solution vector for the equations:"
FOR I = 1 TO N
  PRINT USING "#####.######"; X(I);
NEXT I
PRINT
PRINT
'Now phoney up X and let MPROVE fit it
IDUM& = -13
FOR IQ = 1 TO N
  X(IQ) = X(IQ) * (1! + .2 * RAN3(IDUM&))
NEXT IQ
PRINT "Solution vector with noise added:"
FOR I = 1 TO N
  PRINT USING "#####.######"; X(I);
NEXT I
PRINT
PRINT
CALL MPROVE(A(), AA(), N, NP, INDX(), B(), X())
PRINT "Solution vector recovered by MPROVE:"
FOR I = 1 TO N
  PRINT USING "#####.######"; X(I);
NEXT I
PRINT
PRINT
END