fourier transform of this:

hi this is my shape that i want it's fourier transform

this is my code:

clc
clear all
t=-3:0.0001:3;

%x=-heaviside(t+2)
%y=t
%z=rectangularPulse(t-1)
%unitstep = t>-1;
%ramp = t.*unitstep;

f= -heaviside(t+2)+ heaviside(t+1)+t.*(t>=-1)-t.*(t>=1)+ heaviside(t-1)-heaviside(t-2)

 
figure(1)
plot(t,f)
axis([-3,3,-2,2])

FT=fourier(f)

this is error:

Undefined function 'fourier' for input arguments of type 'double'.

Error in Untitled12 (line 19)

FT=fourier(f)

how could i fix this?

the result of my code:

Answer 1

[KALYAN ACHARJYA]

FT=fft(f);

First FFT then plot, requested you to read this documentation

[HADIMARGO]

and how to plot it?

clc
clear all
t=-3:0.0001:3;

%x=-heaviside(t+2)
%y=t
%z=rectangularPulse(t-1)
%unitstep = t>-1;
%ramp = t.*unitstep;

f= -heaviside(t+2)+ heaviside(t+1)+t.*(t>=-1)-t.*(t>=1)+ heaviside(t-1)-heaviside(t-2)

 
figure(1)
plot(t,f)
axis([-3,3,-2,2])

FT=fft(f)
ezplot(FT,[-3,3])

eror:

Error using ezplot (line 83)

Input must be a character vector expression, function name, function handle, or INLINE

object.

Error in sixth2 (line 20)

ezplot(FT,[-3,3])

[HADIMARGO]

what is different between fourier (f) and fft(f)?

[HADIMARGO]

ok final code:

clc
clear all
t=-3:0.0001:3;

%x=-heaviside(t+2)
%y=t
%z=rectangularPulse(t-1)
%unitstep = t>-1;
%ramp = t.*unitstep;

f= -heaviside(t+2)+ heaviside(t+1)+t.*(t>=-1)-t.*(t>=1)+ heaviside(t-1)-heaviside(t-2)

 
figure(1)
plot(t,f)
axis([-3,3,-2,2])

FT=fft(f)
g = (0:length(FT)-1)*50/length(FT);
figure(2)
plot(g,abs(FT))
axis([-10,60,-2,100])

result:

hope this is true!

[KALYAN ACHARJYA]

Read here (Differences)

I dont have Matlab in my Laptop, I will try when I will return to Lab.