intercept_factorlevel.Rmd

---
title: 'Linear models: effect of changing factor levels as intercept'
author: "FRS"
date: "12 December 2017"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

## Plot 1 as reference

```{r}
## plot1 as reference

trees <- read.csv("data-raw/trees.csv")
trees$plot <- as.factor(trees$plot)
m1 <- lm(height~plot, data = trees)
summary(m1)
library(effects)
summary(allEffects(m1))
library(visreg)
visreg(m1)
```



## Plot 9 as reference


```{r}
trees <- read.csv("data-raw/trees.csv")
trees$plot[trees$plot == 1] <- 11
trees$plot[trees$plot == 9] <- 1
trees$plot <- as.factor(trees$plot)
m1 <- lm(height~plot, data = trees)
summary(m1)
library(effects)
summary(allEffects(m1))
library(visreg)
visreg(m1)

```