t=[0:0.01:0.98];
y1 = sin(2*pi*4*t);
plot(t, y1)

If you draw tha cos function, it will replace the sin function figure to a new one

y2 = cos(2*pi*4*t);
plot(t, y2)

 

So what if I want to draw cos and sin together in one plot?

hold on;
plot(t, y1)
plot(t, y2, 'r') # plot in red color

 

Add labels:

>> xlabel('time')
>> ylabel('value')
>> legend('cos', 'sin')
>> title('my plot')

 

Save the plot:

print -dpng 'myPlot.png'

 

Close the plot:

close

 

 

Figure:

You can tell to generate different figures:

figure(1); plot(t, y1);
figure(2); plot(t, y2);

 

 

Subplot:

subplot(1, 2, 1); # Divides plot a 1 * 2 grid, access first element
plot(t, y1)
subplot(1, 2, 2);
plot(t, y2, 'g')

 

 

axis:

Change the range of axis. axis([x0, x1, y0, y1])

axis([0.5 1 -1 1])

 

Clear the figure:

clf

 

iamgesc:

a = magic(5)
imagesc(a), colorbar, colormap gray; # multi commands in one line