MATLAB Answers Wish-list #2 (and bug reports)
I kind of wish that when we scrolled through the answers to questions (especially when there are many "answers" like this one), ...

etwa 7 Jahre ago | 0

Is there a built-in function that determines whether X/Y coordinates give valid polygon?
My attempt: % Assume polygon is valid answer = 1; % Set tolerance tol = 0.001; % Random set...

etwa 7 Jahre ago | 0

Question

Is there a built-in function that determines whether X/Y coordinates give valid polygon?
If I have a vector of X-coordinates and a vector of Y-coordinates, is there a function that determines whether a valid polygon i...

etwa 7 Jahre ago | 3 answers | 1

### 3

How do you centre your plot at '0' on the X-axis after performing a Fourier transform?
*fftshift* might be what you are looking for. Does this example help? dt = 0.1; % Fs = 1/dt; N = 16; t = (0:N-1)*dt; ...

etwa 7 Jahre ago | 0

how is a Shock response spectrum estimated
You might take a look at this FEX submission: <http://www.mathworks.com/matlabcentral/fileexchange/7398-shock-response-spectr...

etwa 7 Jahre ago | 0

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2D spectral energy density using fft2 - energy in spatial domain unequal to that in wavenumber domain
*[EDIT 7/06]* M=8;N=16; N=8;M=16; dx=0.1;dy=0.2; f = randn(M,N); % Energy in time domain energy_f = sum(sum(f.^2...

etwa 7 Jahre ago | 1

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How can I choose a subset of k points the farthest apart?

etwa 7 Jahre ago | 0

Simple question for GUI
Also wanted to add a good resource for those who want to learn how to program a variety of things in Matlab GUIs: <http://www...

etwa 7 Jahre ago | 0

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Bandpass Filter By Using Butter
Okan - Ambient noise is like random noise... the frequency domain response (if you were to plot the abs of the frequency domain ...

etwa 7 Jahre ago | 0

How can I choose a subset of k points the farthest apart?
Went with a "simple" way - tried to maximize the sum of the distances between each point in the sub-set of "n" below (similar to...

etwa 7 Jahre ago | 0

Legend Problem
Matlab is only doing what you tell it to. One of the places where you define your figure, you have your "hold on" just after you...

etwa 7 Jahre ago | 0

MATLAB Answers Wish-list #2 (and bug reports)

etwa 7 Jahre ago | 1

FFT
Your first amplitude represents 0 frequency. When your data has 0 mean, your first amplitude should also be 0.

etwa 7 Jahre ago | 0

derivative using FFT properties
Based on the website below: <http://www.cl.cam.ac.uk/teaching/2000/ContMaths/JGD-notes/node11.html> I believe you would do...

etwa 7 Jahre ago | 0

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cycles/pixel to cycels/degree

etwa 7 Jahre ago | 0

FFT of an image
See my answer here for a coded up description of what the 2D Fourier transform does using a random 2D image as an example (shoul...

etwa 7 Jahre ago | 0

why real part of fft (exp(at)) is negative in some parts in contrary to analytical calculation of fft(exp(at))?
Try plotting the *abs* result from FFT. Basically, you will not get a purely real, all positive frequency spectrum unless your t...

mehr als 7 Jahre ago | 0

Area of a triangle
How about *polyarea*? >> x = [0, 0, 4]; >> y = [0, 3, 0]; >> area1 = polyarea(x,y) area1 = 6 >> area2 =...

mehr als 7 Jahre ago | 1

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fft2: Frequency and wavenumber
Take a look at my post here for an idea of what is output from FFT2: <http://www.mathworks.com/matlabcentral/answers/24965-ff...

mehr als 7 Jahre ago | 0

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Gaussian FFT
Try plotting the absolute value of the frequency domain amplitudes... when your Gaussian is not centered at time 0, the phase ma...

mehr als 7 Jahre ago | 1

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Anyone using MATLAB on a LINUX OS??
Works fine for me on Redhat... running it on a 12-core, 96GB machine at work. Any simple-ish benchmarks you looking to test/meas...

mehr als 7 Jahre ago | 0

I want to plot PSD for my input data(meters)
If you are measuring displacement in meters in the time domain, then your frequency domain amplitudes (after performing the FFT)...

mehr als 7 Jahre ago | 0

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Difference between fft and manually coding for a fourier transform
You are not correctly defining the frequencies "k" that are associated with the amplitudes in the frequency domain, but it start...

mehr als 7 Jahre ago | 0

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Scaling of fft output?

mehr als 7 Jahre ago | 0

Is there any alternative to if statements inside for loops?
Do you pre-allocated "Pin", if not... then before the for-loops put: Pin = zeros(8760,Ni); The inside of your for-loops ...

mehr als 7 Jahre ago | 0

impulse response interpretation
I reran through the process of generating the Frequency Response data (G) using your code and the one from the FEX just to see i...

mehr als 7 Jahre ago | 0

from time domain to frequency domain and back to time domain
Your "X" has shifted the zero frequency amplitude to the center. You need to use *ifftshift* to get it back where Matlab expects...

mehr als 7 Jahre ago | 0

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I cant generate a square wave in matlab using the square wave command
If you dont have the Signal Processing Toolbox, will the following work as an alternative: y = sign(sin(2*pi*100*t));

mehr als 7 Jahre ago | 0

obtain the Impulse response from a frequency response
N = 1000; % Number of samples df = 20; % Frequency increment (in Hertz) Nyq = 10000; % Nyquist Frequency (in Hertz) ...

mehr als 7 Jahre ago | 4

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