hi Fidelis --
talking of EDDC, I'm running into a bit of wierdness with the equation
published in http://osbf-lua.luaforge.net/papers/osbf-eddc.pdf --
specifically the final CF(F) equation on page 5. Using the K1, K2 and K3
values suggested, I cannot reproduce the values in the graph below it.
According to the graph, what I should see are values like this:
Dfs Dfh CF
100 100 0
0 100 1
100 0 1
what I actually get are:
Dfs Dfh CF
100 100 1.19134681363401e-07
0 100 0.124843632959153
100 0 0.124843632959153
Here's the (perl) code I used to implement this:
my $Dfs = 100;
my $Dfh = 0;
my $weight = 3125; # demo, assume a strong token
my $K1 = 0.25;
my $K2 = 10;
my $K3 = 8;
my $NDfs = $Dfs; # assume Dfs/Dfh are normalized for demo purposes
my $NDfh = $Dfh;
my $Sumf = $Dfs + $Dfh; die "assert: Sumf == 0" unless $Sumf;
my $NDeltaf = $NDfs - $NDfh;
my $NSumf = $NDfs + $NDfh;
my $WdotSumf = $weight * $Sumf;
# the CF(F) equation
my $CF = (((($NDeltaf ** 2) + ($NDfs * $NDfh) - ($K1 / $Sumf))
/ ($NSumf ** 2)) ** $K2)
* ($WdotSumf
/ (1.0 + $K3 * $WdotSumf));
print "s=$Dfs h=$Dfh w=$weight cf=$CF\n";
(sorry about the perl, but hopefully it's readable enough.)
I've run through this logic on paper, against the equations, and I can't
spot an error -- the equation really seems to produce incorrect output.
Could you take a look? Am I missing something?
--j.
