search for: sxx1

Displaying 1 result from an estimated 1 matches for "sxx1".

Did you mean: sx1
2008 Jun 04
1
Comparing two regression lines
...of the R script is appended below. How would you proceed? Many thanks for your help! Best wishes, Christoph ## lm1=lm(y1~x) # y1 and y2 are different response variables, scaled to [0;1] using a ranging transform lm2=lm(y2~x) # n is 12 for each regression model3=lm(y~x*FACTOR) summary(model3) sxx1=sum((y1-mean(y1))^2) sxx2=sum((y2-mean(y2))^2) s.pooled=(4805.2+6946.6)/20 SED=sqrt(s.pooled*(1/sxx1+1/sxx2)) t=(528.54-446.004)/SED #residual SS from lm1 and lm2 divided by SED qt(0.025,20) #compare with t distribution at 20 d.f. ## #(using R 2.6.2 on Windows XP)