On Sunday, April 14, 2019 at 6:56:16 PM UTC+2, Karl Ratzsch wrote:
Am 14.04.2019 um 17:19 schrieb hugocoolens@gmail.com:
I am puzzled by the following discrepancy between a stats command result and the result which I have from normal Gnuplot fitting:
f(x)=a*log10(x)+b
a=-1.06
b=-4.78
fit [3e-3:1] f(x) datafile using ($1):($2) via a,b
stats [3e-3:1] datafile using (log10($1)):($2)
The Gnuplot fitting gives me y=ax+b, with the correct a=-1.16816 and b=-4.78604
But the stats-command gives: y = -3.104 x - 4.194
Not problem with fit or stats, your range setting for stats was
wrong: you have to logarithmise it as well
stats [log10(3e-3):log10(1)] $dat using (log10($1)):($2)
and the linear model that comes out is y = -1.168 x - 4.786
;-)
Thanks a lot!
kind regards,
Hugo
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