# R Studio Tutorial Exercise
## Problem 1
**Using the ChickWeights dataset, create boxplots showing log10 weights only on the first, tenth, and last days of the experiment.**

First, load and view the data

data("ChickWeight")
dim(ChickWeight)
names(ChickWeight)
head(ChickWeight)

Then change the column names for easy use!

colnames(ChickWeight) <- c("weight", "days", "individual", "diet")

### Problem 1 Data
To use only the first, tenth, and last days of the experiment, I created a new variable `new.days`.
(I guessed you meant day=0 for the first day since day=1 does not exist)

day21<-which(ChickWeight$days == max(ChickWeight$days))
day0<-which(ChickWeight$days == 0)
day10<-which(ChickWeight$days == 10)
justdays <- c(day0, day10, day21)
ChickWeight[justdays,]
new.days<-ChickWeight[justdays,]

This creates variables (`day21`,`day10`,`day0`) that just contain the different days, which can be combined into `justdays` and then used to define `new.days`, which is a variable that contains all the information from the `ChickWeight` matrix, but for only the specified days.

### Boxplot

boxplot(log10(new.days$weight) ~ new.days$days,
        names=c("First Day","Day 1","Day 21"),
        xlab="Days",
        ylab="log10 Weights",
        main="Problem 1 Boxplot")

This creates a boxplot with weights of chicks on the different days!

### Challenge 1a
**Have the figure display results for each diet separately.**

library(ggplot2)
C1a <- ggplot(new.days, aes(x=diet, y=log10(weight))) + 
  geom_boxplot() +
  geom_jitter(position = position_jitter(width = 0.2, height = 0))+
  ggtitle("Weights of chicks based on different diets") +
  xlab("Artifical diet number") +
  ylab(expression(paste(log[10]," chick weight (g)", sep=""))) +
  theme_bw()
C1a

This plots this ggplot:
The plot shows the weights of chicks based on different diets but just the chicks from the first day, day 10, and last day.

***Oops this should have actually been done differently, with ggplot to make it so that there are 4 different graphs o.o***
***+the images don't load unless I am logged onto the BI376 rstudio server***

### Challenge 1b
**With the figure features above, communicate both the individual values and the distribution of those values to a viewer.**
This can be done by plotting the same data with jitters in a violin plot! The violin plot shows the distribution more clearly than a boxplot while the jitters show the individuals as points on the plot.

C1b <- ggplot(new.days, aes(x=diet, y=log10(weight))) + 
  geom_violin(trim = FALSE) +
  geom_jitter(position = position_jitter(width = 0.2, height = 0))+
  ggtitle("Weights of chicks based on different diets") +
  xlab("Artifical diet number") +
  ylab(expression(paste(log[10]," chick weight (g)", sep=""))) +
  theme_bw()
C1b

## Problem 2
**Randomly generate two vectors of 100 values each. Plot them against one another and draw a linear trend line through the group of points.**

a <- rnorm(n=100)
b <-runif(n=100)
plot(a,b)
trendline<-lm(b~a)
abline(trendline)

Vectors `a` and `b` of 100 values were created and plotted. The line was saved as `trendline` for easy use later on.

### Challenge 2a
**Find the slope of the line you’ve drawn above.**

trendline
#(Intercept)     a  
#0.47722      0.04658  

This gives both the intercept (0.47722) and slope a (0.04658).

### Challenge 2b
**Add text to the plot, showing the slope.**

equation<- ("y=0.04658x + 0.47722")
mtext(equation)

Using what was learned from challenge 2a, the equation in the form of y=mx+b can be made by plugging in the intercept and slope. Using `mtext` allows us to put the text we want on the plot.

**Done!**