Formatted Read Accuracy

[Toon Moene]

Emil Block wrote:

> When reading a number from an input file with a formatted read statement the
> value is not represented correctly when using the G77 compiler. For example,
> 
>    read (line,3) xllt
> 3  format(f9.4)  
>      
> input xllt is  67.9936  and it becomes 67.9935989  
> 
> Anyone know how to correct this?

You can't.  67.9935989 is the approximation that's choosen by the input 
algorithm of 67.9936 because the latter can't be represented exactly in 
single precision floating point format.

You simply have to live with this, because it's a feature of dealing 
with floating point values.

Hope this helps,

-- 
Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
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