[t yr mo day rad] = textread('Ohare_Solar.txt','%d%d%d%d%f','headerlines',1);
figure(1);
plot(t,rad,'k+');
xlabel('Day of Year');
ylabel('Daily Average Solar Radiation');
title('Figure 3.9: Solar Radiation Levels in 2005');

figure(2);
plot(t,rad,'k-');
xlabel('Day of Year');
ylabel('Daily Average Solar Radiation');
title('Figure 3.10: Solar Radiation Levels in 2005');