Real*8 or Double Precision Must Contain an Exponent

ID: Q31173


The information in this article applies to:
  • Microsoft FORTRAN for MS-DOS, versions 4.0, 4.01, 4.1, 5.0, 5.1
  • Microsoft FORTRAN PowerStation for MS-DOS, versions 1.0, 1.0a
  • Microsoft Fortran Powerstation 32 for Windows NT, versions 1.0, 4.0


SUMMARY

When using real*8 or double-precision variables, the FORTRAN manual says double-precision real constants have the same form as single-precision constants, except that the letter D is used for exponents instead of the letter E, and that an exponent part is mandatory.

To get 15 digits of precision into your real*8 variables, you must declare the constant with an exponent. If the exponent is omitted, the number is interpreted as a single-precision constant.


MORE INFORMATION

The following is a code example of the proper way to set a double-precision variable with the D:


            real*8 doub_real
   c      double precision doub_real
   c      either real*8 or double precision needs to use the D.


         doub_real = .55555555555555555555D0
         print '(f20.18)',doub_real
         end 

Additional query words: kbinf 4.00 4.10 5.00 5.10

Keywords : kbcode kbFortranPS kbLangFortran
Version : :1.0,1.0a,4.0,4.01,4.1,5.0,5.1
Platform : MS-DOS NT WINDOWS
Issue type :


Last Reviewed: November 3, 1999
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