Lesson topics

Demo 6

								        program demo6

c       This program demonstrates base 2 conversion round-off error.
c       For x and y, single precision round-off error occurs at the
c       9th digit. For z, double precision round-off error does not
c       occur until the 17th digit. Although y is a double precision
c       variable, its value is prescribed only in single precision,
c       and so double precision is lost.

        real x
        double precision y, z
        x = 1.1
        y = 1.1
        z = 1.1D0
        print *, "x = ", x
        print *, "y = ", y
        print *, "z = ", z
        write (*,5) "More precisely, x, y, z have the values ", x, y, z
 5      format (a,/,3f20.16)
        end