% multi_plot.m
% Example for plotting several sets of data on a single graph
% adapted from http://web.cecs.pdx.edu/~gerry/MATLAB/plotting/loadingPlotData.html
% BJ Furman
% 15NOV2009

%  read data into PDXtemperature matrix 
load('PDXtemperature.dat');

%  copy first column of PDXtemperature into month
month = PDXtemperature(:,1);

%  and second column into high_temp
high_temp = PDXtemperature(:,2);

%  and third column into low temp
low_temp = PDXtemperature(:,3);

%  and fourth column into avg temp
avg = PDXtemperature(:,4);

% generate the plot
plot(month,high_temp,'ko',month,low_temp,'k+',month,avg,'k-');

% add axis labels and plot title
xlabel('Month');                      
ylabel('temperature (degrees F)');
title('Monthly average temperature for Portland International Airport');

%  add a plot legend using labels read from the file
legend('High','Low','Avg');
grid on