Rsquared for anova
Dorien Herremans <dorien.herremans <at> ua.ac.be> writes:
Thanks Dieter, Even if I use lm(), I get the following output:
summary(fit)
? ? ? ? ? ? ?Df ?Sum Sq Mean Sq F value ? ?Pr(>F) nh1 ? ? ? ? ? ?1 ? 324.0 ?323.99 ?139.13 < 2.2e-16 *** nh2 ? ? ? ? ? ?1 ? 723.1 ?723.12 ?310.53 < 2.2e-16 *** nh3 ? ? ? ? ? ?1 ?1794.2 1794.21 ?770.49 < 2.2e-16 *** Residuals ? 4604 10721.2 ? ?2.33 --- Signif. codes: ?0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? no R squared to be found.
Really ?? When I run the example in ?lm I get:
summary(lm.D9)
Call:
lm(formula = weight ~ group)
Residuals:
Min 1Q Median 3Q Max
-1.0710 -0.4938 0.0685 0.2462 1.3690
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 5.0320 0.2202 22.850 9.55e-15 ***
groupTrt -0.3710 0.3114 -1.191 0.249
---
Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1
Residual standard error: 0.6964 on 18 degrees of freedom
Multiple R-squared: 0.07308, Adjusted R-squared: 0.02158
F-statistic: 1.419 on 1 and 18 DF, p-value: 0.249
Note the last three lines. I would be shocked if there
weren't a similar set of information in your output ...
Your output looks like the result of summary(aov(...))
Another strange thing. I did the same calculations in SPSS and got different results, among others, higher p values. lm() and aov() just do linear regressions (anova) right? I tried with the same factorial variables (without interaction effects to test).
There are a lot of things that could be different. Are you treating factors (categorical predictors) as numeric by accident?
Thanks! On 15 April 2011 18:07, Dieter Menne <dieter.menne <at> menne-biomed.de> wrote:
dorien wrote:
I calculate an anova test in the following way: ... aov example I want to check the fit of the model with Rsquared
Try summary(lm(...)) instead. Dieter -- View this message in context:
http://r.789695.n4.nabble.com/Rsquared-for-anova-tp3452399p3452434.html
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-- Dorien Herremans Department of Environment, Technology and Technology Management Faculty of Applied Economics University of Antwerp B.513 Prinsstraat 13 2000 Antwerp Belgium +32 3 265 41 25