Dear R users.
I have an urgent question to make you, hopefully you can help me.
This is my first time making an ancova test in R. I have finished the model
design and now I need to plot it. I have found several online sources where
the mechanics for plotting data is explained, nevertheless all of these
explain the mechanics for plotting the data when there is no interacion
which is not my case. I was thinking to subset the data following this
example (
http://r-eco-evo.blogspot.com/2011/08/comparing-two-regression-slopes-by.html
),
but I do not know if it will be the best choice.
If some of you could suggest me a document which explains this in detail or
may be help me with the data set,
a<-read.table ("test1ancova.txt", header=T)
attach(a)
names(a)
fit3<-lm(log(Peso) ~ especie * Radio)
summary(fit2)
Call:
lm(formula = log(Peso) ~ especie * Radio)
Residuals:
Min 1Q Median 3Q Max
-1.15349 -0.29033 0.04444 0.39277 1.41267
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 2.0610 0.2050 10.054 5.84e-11 ***
especieNops 1.8253 0.3002 6.080 1.28e-06 ***
Radio 0.3827 0.1414 2.707 0.0113 *
especieNops:Radio -0.3749 0.1438 -2.608 0.0142 *
---
Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1
Residual standard error: 0.5418 on 29 degrees of freedom
Multiple R-squared: 0.7005, Adjusted R-squared: 0.6695
F-statistic: 22.61 on 3 and 29 DF, p-value: 9.578e-08
plot(a$Radio,a$Peso, type="n",xlab="Ratio", ylab="Weight")
points(a$Radio[1:15], a$Peso[1:15], col="red")
points(a$Radio[16:30], a$Peso[16:30], col="blue")
Any help will be really appreciated!
Thanks in advance