Wrong results from anova
Li Li -
I belive it's a rounding error -- try setting
options(digits=8)
before displaying the output:
summary(fit.Y)
Df Sum Sq Mean Sq F value Pr(>F) sample.Y 3 2203 734 190706 <2e-16 *** Residuals 8 0 0 --- Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1
summary(fit.Y)
Df Sum Sq Mean Sq F value Pr(>F) sample.Y 3 2202.70 734.23 190706 < 2.2e-16 *** Residuals 8 0.03 0.00 --- Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1 - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spector at stat.berkeley.edu
On Tue, 14 Apr 2015, li li wrote:
Hi all, I have following data. When I perform an anova, the residual sum of square returns to be zero. But this is wrong, since we can hand calculate the RSS to be around 0.0308. Did anyone come across the same problem before? Any suggestions? Thanks. Hanna
ydata
Y sample.Y 1 0.477 0.5 2 0.477 0.5 3 0.478 0.5 4 27.320 27 5 27.420 27 6 27.300 27 7 29.440 29 8 29.620 29 9 29.610 29 10 35.840 35 11 35.900 35 12 35.850 35
fit.Y <- aov(Y~sample.Y, data=ydata) summary(fit.Y)
Df Sum Sq Mean Sq F value Pr(>F) sample.Y 3 2203 734.2 190706 <2e-16 *** Residuals 8 0 0.0 --- Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1 [[alternative HTML version deleted]]
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