:D Looks like two separate off-by-one error (OBOE) errors to me :)

First you start with non-zero and add 40 times (one too many), then you start with non-zero and add 41 times (one too many twice).

If you start with non-zero you need to add only 39 times, or start with zero and add 40 times :)

In short 

perl -MData::Dump -e " @f = map { 0.001 } 1 .. 40; dd\@f; $o = 0; for(
+@f){ dd $o+=$_; } dd int @f; dd $o/int(@f); "

perl -MData::Dump -e "  $o = 0; for(1 .. 40){ dd $o+= 0.001; } dd $o/4
+0; "

[download]

It didn't dawn on me to check wickedjesters (or your) math until ww raised the quesiton

In reply to Re^2: Is this odd behavior a floating point problem? by Anonymous Monk
in thread Is this odd behavior a floating point problem? by wickedjester

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