Difference between revisions of "Floating point math issues"

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(New page: From [http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/8b367f44c419fa1d/|http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/8b367f44c419fa1d/] :Th...)
 
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From [http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/8b367f44c419fa1d/|http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/8b367f44c419fa1d/]
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:Thank you to all that offered their suggestions for a "safe division" routine to prevent overflow. For those that are curious about the solution to the problem, I found useful to adopt a subroutine along the lines suggested by William Long:  
 
:Thank you to all that offered their suggestions for a "safe division" routine to prevent overflow. For those that are curious about the solution to the problem, I found useful to adopt a subroutine along the lines suggested by William Long:  

Revision as of 14:11, 9 April 2008

From http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/8b367f44c419fa1d/

Thank you to all that offered their suggestions for a "safe division" routine to prevent overflow. For those that are curious about the solution to the problem, I found useful to adopt a subroutine along the lines suggested by William Long:
    if(exponent(a) - exponent (b) >= maxexponent(a) .OR. b==0)Then 
     q=altv 
    else 
     q=a/b 
    endif 
The = in the >= is to take into account the case when the fractional part of a is 1.111... and that of b is 1.
It works very well.
Thank you again,
Julio.