FORTRAN -Returning index fir which values fall in a region

Applications Programming
1

I have an 10 element array containing numbers, I want the start and end index in the array for which the values lie between DIST1 and DIST2. It is not working quite right. I also might want a value of 0 if I cannot find an index.

    V=(/10.0,20.0,30.0,40.0,50.0,60.0,70.0,80.0,90.0,100.0/)

    PRINT *, V
    PRINT *, DIST1, DIST2
    I = 1
    ISTART = 0
    DO WHILE ((V(I) < DIST1).AND.(I <= 10))
      ISTART = ISTART + 1
      I = I + 1
    END DO

    I = 0
    IEND = 0
    DO WHILE ((V(I) <= DIST2).AND.(I <= 10))
      IEND = IEND + 1
      I = I + 1
    END DO
    IEND = IEND - 1
2

Add some print statements in the do while loop to show I, ISTART, and V(I)
Add a print statement after the end do as well.
You should also add a routine to make sure that V is in ascending order, and that DIST1 is not greater than DIST2

3

I think I have fixed the problem now. Am trying to check id array is in ascending order.

---------- Post updated at 01:40 PM ---------- Previous update was at 01:24 PM ----------

Have tried this to check if array is in ascending order but there is a problem. The first time statement is false I want to exit and return false.

    DO I = 1, N-1
      IF (VDIST(I) < VDIST(I+1))
          L_ASCENDING = .TRUE.
      ELSE
          L_ASCENDING = .FALSE.
      ENDIF
    ENDDO

---------- Post updated at 01:53 PM ---------- Previous update was at 01:40 PM ----------

Done it now.

4

Sort an array. Univac Fortran V. I don't think that the implicit statement is still supported though, and I don't have a compiler to confirm that there are no typos in the following code.

     *DIMENSION TABLE (14,500)
     *FILL TABLE WITH DATA AND SORT ON COLUMNS 2,1,3

     SUBROUTINE TXSORT
     IMPLICIT INTEGER (A-Y)
     X0=TABCTR         * TABCTR IS ONE MORE THAN NUMBER OF ENTRIES IN THE TABLE.
10   X0=X0/2
     IF (X0) 15,70,15
15   X1=TABCTR-X0
     X2=1
20   X3=X2
30   X4=X3+X0
     IF (TABLE(2,X3)-TABLE(2,X4)) 60,45,40
45   IF (TABLE(1,X3)-TABLE(1,X4)) 40,46,60
46   IF (TABLE(3,X3)-TABLE(3,X4)) 60,60,40
40   DO 50 I=1,14
     X5=TABLE(I,X3)
     TABLE(I,X3)=TABLE(I,X4)
     TABLE(I,X4)=X5
50   CONTINUE
     X3=X3-X0
     IF (X3-1) 60,30,30
60   X2=X1
     IF (X2-X1) 20,20,10
70   RETURN
5

Have written a subroutine that gives an error if values are not in ascending order. In my case, I do not sort the array. This is because should the values not be in ascending order, then there must be a problem with the data.