Real numbers as DO indices are from Fortran 95 on not any more a part of the standard. Using the ISO option when compiling (Plato) is supposed to ensure that the code is in agreement with the standard. However the compiler (version 5.10 and earlier) does not block real numbers as DO indices. This is demonstrated in the following example code:
OPTIONS( ISO ) ! To ensure that the code is in agreement with the Fortran 95 standard PROGRAM trigonometrisktabell_ISO IMPLICIT NONE REAL, PARAMETER :: PI = 3.1415927 REAL :: radianer, grader, faktor
WRITE( *, * ) ' Vinkel Sinus Cosinus' faktor = 2.0 * PI / 360.0 DO grader = 0.0, 90.0, 0.1 ! Should produce a compilation error message radianer = grader * faktor WRITE( *, * ) grader, SIN( radianer ), COS( radianer ) END DO
END PROGRAM trigonometrisktabell_ISO