How to plot two different curves on same axes?

 I have to plot for COD vs TIME. I have discrete values of COD against time and also expression for relationship between COD and TIME. I can plot both the cases differently.
So, how can I merge the two curves of COD and TIME on same axes?

Answer 1

[Joseph Cheng]

Yes you can, read the documentation on plot(). There should be sufficient examples showing how to plot plenty of items on one axes.

Answer 2

[Azzi Abdelmalek]

plotyy(t,x1,t,x2)

Answer 3

[Star Strider]

This will do what you want. Adapt it as needed:

TIME = linspace(0, 10, 20);
COD  = randi(10, 1, length(TIME));

xmtx = [ones(length(TIME),1) TIME'];
B = xmtx\COD';                          % Linear Regression: COD - TIME
COD_fit = xmtx*B;                       % Fitted Line

figure(1)
plot(TIME, COD, 'bp')
hold on
plot(TIME, COD_fit, '-r')
hold off
grid
xlabel('TIME')
ylabel('COD')
legend('Data','Linear Fit')
axis([xlim    0  11])

It does a linear regression on COD as a function of TIME to create the relationship so it has something to plot, and to demonstrate the technique.

EDIT: Added plot.