RMardown example

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Setting up

Running some code

This script won’t do much, but let’s explore R’s built-in trees dataset (some physical data on 31 black cherry trees). The following code chunk loads the data and prints it. The code block starts and ends with three backticks (`). The text in the curly brackets at the top ({}) tells the interpreter that the code is R code and gives the chunk a label, which can be useful for debugging.

# first load the data
data(trees)
# then print it
trees
##    Girth Height Volume
## 1    8.3     70   10.3
## 2    8.6     65   10.3
## 3    8.8     63   10.2
## 4   10.5     72   16.4
## 5   10.7     81   18.8
## 6   10.8     83   19.7
## 7   11.0     66   15.6
## 8   11.0     75   18.2
## 9   11.1     80   22.6
## 10  11.2     75   19.9
## 11  11.3     79   24.2
## 12  11.4     76   21.0
## 13  11.4     76   21.4
## 14  11.7     69   21.3
## 15  12.0     75   19.1
## 16  12.9     74   22.2
## 17  12.9     85   33.8
## 18  13.3     86   27.4
## 19  13.7     71   25.7
## 20  13.8     64   24.9
## 21  14.0     78   34.5
## 22  14.2     80   31.7
## 23  14.5     74   36.3
## 24  16.0     72   38.3
## 25  16.3     77   42.6
## 26  17.3     81   55.4
## 27  17.5     82   55.7
## 28  17.9     80   58.3
## 29  18.0     80   51.5
## 30  18.0     80   51.0
## 31  20.6     87   77.0

What’s the average girth of the trees? (the dataset doesn’t specify a unit)

mean(trees$Girth)
## [1] 13.24839

If the R code produces graphics, they will show up in the document. Let’s try with a simple histogram of tree girths:

hist(trees$Girth)

You can add more bins to the histogram too:

hist(trees$Girth, breaks = 10)