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Bug fixed in CVS.
Thanks for reporting the problem!
I believe there's a bug in PDL::Primitive with the rms
equation.
It is currently:
$rms = sqrt( ((($data-$mean)**2 )->dsum) /
$npts );
I think it should be:
$rms = sqrt( ((($data-$mean)**2 )->dsum) /
($npts-1) );
This should be repeated for the weighted sum
calculation that follows as well. With the appropriate
divide by zero conditionals of course.
When I fixed the code the rms values agreed with similar
calculations done with Excel and Jump.
You can reach me at
jwelter@sawtek.com
Jason Welter
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Bug fixed in CVS.
Thanks for reporting the problem!
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I think I was wrong now.
Dividing by N is appropriate when calculating the rms for an entire
population.
Dividing by N-1 is appropriate when calculating the rms for a
subgroup of the entire population.
I think the first assumption is the most correct and think you should
ignore my bug report...sorry.
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