[求助] 空间插值 程序代码有问题

C     空间插值
C     --------------------------------------------------
DOWN = 0.0
      UP = 0.0
      MU = 2
C
      DO I=1,10125
        Distance = (COORDS(1) - P_time(I,1))**2
     &           + (COORDS(2) - P_time(I,2))**2
     &           + (COORDS(3) - P_time(I,3))**2
        Distance = Distance**0.5
        IF(Distance == 0)THEN
          DOWN = 1
          UP = P_time(I,4)
          EXIT
        ELSE
          DOWN = DOWN + 1 / Distance**MU
          UP = UP + P_time(I,4) / Distance**MU
        END IF
      END DO
C
      F = UP / down

C     空间插值
C     --------------------------------------------------
      DOWN = 0.0
      UP = 0.0
      MU = 2
C
      DO I=1,size(P_time,1)
        Distance = sqrt(dot_product(coords(1:3),P_time(I,1:3)))
        IF(Distance < 1.e-6)THEN
          DOWN = 1
          UP = P_time(I,4)
          EXIT
        ELSE
          DOWN = DOWN + 1 / Distance**MU
          UP = UP + P_time(I,4) / Distance**MU
        END IF
      END DO
C
      F = UP / down