F90 precision problem

[Jennifer Middleton]

I am using F90 on HP-UX 10.20. When I assign values to a double precision array using a data statement, the values are changed slightly. i.e 0.040 becomes .0399999910593033. This slight change is actually affecting the output. This same program did not have this problem in F77. Is this a known F90 bug?

[linuxfan]

Hi Jennifer,

Do you have any patches for fortran or libcl?
There is a patch PHSS_15255(Description says)
1. Fortran formatted real output has a generic accuracy problem caused by sometimes rounding a formatted value twice. This can result in a formatted value that is too large.

You can try installing the latest patch for libcl PHSS_22652 to fix this problem

Also not sure if you already have the fortran90 cumulative patch (PHSS_13307)

-Ramesh

[Jennifer Middleton]

Thanks, I loaded the patches but unfortunately I still have the same problem.

[linuxfan]

Hi Jennifer,

which version of fortran are you using?

HP recommends
s700_800 10.X FORTRAN 90 1.0 cumulative patch(PHSS_13307)
s700_800 10.20 Fortran90 B.10.20.16 Cumulative Patch(PHSS_20205)
s700_800 10.X Fortran90 B.10.20.(19|20|27) cumulative patch(PHSS_23952)

We don't use Fortran so my knowledge is limited, hoping someone else can help you out here.

-Regards
Ramesh