Scatter plots

# Scatter plots

# Example data: "scatter.txt" (tab separated)
Week	pH	Treatment	Location
0	5.58	Zero	Soil
2	5.245	Zero	Rhizo
4	5	Zero	Soil
5	4.9025	Zero	Soil
0	4.9	Zero	Rhizo
2	4.85	Zero	Rhizo
4	4.845	Zero	Rhizo
5	5.1375	Zero	Soil
0	5.17	High	Soil
2	5.0425	High	Soil
4	5.3025	High	Rhizo
5	5.155	High	Rhizo
6	5.6275	High	Soil

# ie four variables: week, pH, treatment, location

# libraries needed:

library(ggplot2)

# read in table from wkdir
data <- read.table("scatter.txt", header = TRUE, , sep='\t')

k <- ggplot(data, aes(x=Week,y=pH, color = Treatment)) + 
  geom_point(aes(shape=Location),
             size = 4) 
k # print and check

# change colours 
k2 <- k + scale_color_brewer(palette="Set1") + theme_bw() + theme(text = element_text(size=12, color = "black"))

## now add axis labels and title   
k3 <- k2 +  labs(title = "pH change with time in High & Zero Plots") 

## Editing title to make space beneath it and to change size and font face

k3 + theme(plot.title = element_text(size=12, face="bold", vjust=2))