Hello, I have data ( link ) from a completely randomized experiment, where the (0.25, 0.50, 0.75, and 1.00) of different fungicides (4 natural + 1 chemical + control) with water). In total there were 24 treatments x 4 replications each.
Since I do not have a R domain, I would like to know the appropriate script to perform the ANOVA, the regression and generate the graphs already adjusted for each situation.
Sincerely
dados <- read.table('IVCM.txt', header = TRUE)
regLin <- lm(IVCM ~ TRAT * RE, dados)
# o asterisco na fórmula indica que é para calcular também a interação
# você pode usar "+" no lugar se quiser o cálculo sem interação
summary(regLin) # resumo do modelo
anova(regLin) # tabela ANOVA
par(mfrow=c(2,2)); plot(regLin) # gráficos de avaliação
Remember to check the model assumptions and the setting. In their example data, the waste does not follow Normal distribution, among other things. You can try a generalized linear model: it is run in R by using the glm function, which uses the same formula syntax, but with the addition of specifying the probability function.
An excellent guide to linear models in R is Chapter 9 of the book Ecological Models and Data in R. It is available in PDF from the author's website: link