Quiz 1 (10 minutes, 3 points):

General instructions: for all quizes:
1) Before you log out, cut/paste your code into an email to your TA.
2) Make sure your code works!
3) If the code is designed to make a plot, do NOT send the plot; send just the code.
4) Quiz solutions emailed after the end of the lab will NOT be accepted.
5) The solutions to the quizes generally involve code you have already typed in
during the lab session. So, use your up/down arrows to expedite matters.


a) Write code for reading-in data for quiz 1 from
http://www.stat.washington.edu/marzban/390/gamma_dat.txt 
and calling it DAT .

b) Write code for assigning the second column of DAT to a variable called x.

c) Write code for plotting the histogram of x with breaks=20.



Soln:

# a) 
DAT=read.table("http://www.stat.washington.edu/marzban/390/gamma_dat.txt",header=F)
# b) 
x = DAT[,2]
# c) 
hist(x,breaks=20)   # Skewed to the left. 

# Also, note that you actually don't get 20 breaks! That's because
# hist() still tries to do some fancy business that we don't need to know!
# Just be aware that the actual number of breaks is not always the same as
# the value of breaks in hist().