Need help making a stairs graph

Hi can anyone tell me how to make a stair graph? For example, I have two y values, the fist is 3 when x is from 0 to 4, the second is -3 when x is from 4 to 8.

Since the total length is 8, I put

x=8;

y=??;

but what do I need to put for y? when there are two difference values but I need them on the same graph.

stairs(x,y)

Best Regards

Samious

Answer 1

[Image Analyst]

Try this:

x = 0 : 8
y = [3,3,3,3, -3,-3,-3,-3,-3];
stairs(x, y, 'bo-', 'LineWidth', 3);
ylim([-4, 4]);
grid on;

[Samious]

just a quick question though, if x is an unknown number, eg (b), what do I need to put in y? (point a is in the middle)

3, between 0 and a, -3 between a and b

will this work?

x=0:b y=[3*(b-a),-3*(a+(b-a))]?

[Image Analyst]

Here's some more general code to handle that:

amplitude = 4.3;
b = 8;
a = 3;
x = [0 : a, a : b]
y = [amplitude * ones(1, a+1), -amplitude * ones(1, length(a:b))]
stairs(x, y, 'bo-', 'LineWidth', 3);
ylim([-5, 5]);
grid on;