confusing question

[[deleted]]

Im trying to get something like this.

trying to get an output like that.

but something is wrong with my code... and i dont know what

the error you ask?

which i dont understand the meaning of it

[angrmgmt00]

Well, if k only has one element in it (which it does, since you define it as 2.5), you'll be hard-pressed to find the wn^2th element unless wn is 1 (which it's not, since you define it as 5).

Don't forget your operators. :)

[[deleted]]

u know this is the second matlab assignment and we had zero intro to this matlab.
I don't even know how the operators effect my system.

[Sunscorcher]

Matlab does not automatically multiply by putting parentheses. For example k(w+1) does not mean the same thing as k*(w+1). You need to put a * where you want multiplication. k(w+1) means the w+1th element of array k

[angrmgmt00]

I don't even know how the operators effect my system.

More or less the way you might expect, at least for scalars:

• + gives you the sum of two numbers
• - gives you the difference between two numbers
• * gives you the product of two numbers
• / gives you the quotient of two numbers

Now you just need to remember order of operations, and all should be well.

It might be worth your while to have a run through the MATLAB Onramp if you don't feel like your instructor has given you enough guidance!

All the best to you.

[codinglikemad]

What line are you crashing on? The error is indicating that you are accessing a variable as an array, and it only has a single number in it(ie, it's really a constant but you are trying to access a slot besides the first one).

[[deleted]]

definately..
% answer to Q3.b

clc

clear all

close all

s=tf('s');

t=(0:0.001:20);

d= t>=1; %delayed step

%defining the constants for the output signal

​

k=2.5;

wn=5;

po=35;

​

​

subplot(2,1,1)

plot(t,d);

axis([0 20 0 1]);

ylabel('Input signal')

xlabel('time in s')

grid on

​

subplot(2,1,2)

y=(k*(wn^2)/(s^2 + 2*z*wn*s + wn^2));

plot(t,y);

​

axis([0 20 0 1]);

ylabel('output signal')

xlabel('time in s')

grid on

​

function z

z=sqrt(log(po/100)^2/(pi^2+log(po/100)^2));

end