URG: How to get the data points from the fft plot of Matlab?

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quantumeb

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Hi All,

I used Matlab 6.0 to make a fft plot from an input signal...
What command should i use to get all the data points for that plot???
Please help...
This is an urgent issue...

Thanks
 

I get confused with you statement. It comes to me that you perhaps perform the FFT of the input signal via the command "fft" in Matlab. If such a case, you can use the "ifft" to get back the input signal.
 

    quantumeb

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Re: URG: How to get the data points from the fft plot of Mat

Hi Dude,

Thank you for drop by...

Actually, I know how to use the fft and ifft in matlab...
However, i need to put some "marker" in the graph...
So, the reviewer can see the "data points" in the graph clearly...
I have just managed to use the "axis properties" and change it....
Sorry for the confusion....

Actually, I have another question...
If I have a non-uniform/non-linear input signal, then I use fft to plot it...
Of course, there will be randomness in the output fft signal...
Is there any command in matlab that I can list down all the data points?
(e.g. : x = 1, y = 1; x = 2, y = 3....)
 

u can use this ,suppose the input is x
A = [x,abs(fft(x))];
then type in A
 

Re: URG: How to get the data points from the fft plot of Mat

For plotting info see the link:
https://www.mathworks.com/matlabcen...&objectName=Plot Annotation and Customization

For the data points of A:
if A =[1XN]
then X will be time and Y will be A.
If A = [2XN] then A(1, =X) and A(2, = Y)

%i.e.
t=[0:15];
y=t.^2;
x=t; %Just to have (x,y)

A=[x;y];

plot(A(1,,A(2,)

* NOTE alll of the Happy Faces need do be replaced with a : followed by a )
 

Re: URG: How to get the data points from the fft plot of Mat

LOSTINCITY said:
u can use this ,suppose the input is x
A = [x,abs(fft(x))];
then type in A

tnx 4 this... but, this will cost me a lot of time....

Added after 1 minutes:


tnx... I will try it first...
 

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