Answered
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...

mer än 12 år 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...

mer än 12 år ago | 3 answers | 1

3

answers

Answered
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; ...

mer än 12 år ago | 0

Answered
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...

mer än 12 år ago | 0

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Answered
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...

mer än 12 år ago | 1

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Answered
How can I choose a subset of k points the farthest apart?
Added a few more tests (including your latest) and added your data (instead of just random dataset), which may be of interest. R...

mer än 12 år ago | 0

Answered
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...

mer än 12 år ago | 0

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Answered
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 ...

mer än 12 år ago | 0

Answered
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...

mer än 12 år ago | 0

Answered
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...

mer än 12 år ago | 0

Answered
[DISCONTINUED] MATLAB Answers Wish-list #2 (and bug reports)
Has someone already addressed the change from having our most recent answers listed first to (now) where our oldest answers are ...

mer än 12 år ago | 1

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

mer än 12 år ago | 0

Answered
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...

mer än 12 år ago | 0

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Answered
cycles/pixel to cycels/degree
See this link: <http://www.cogs.susx.ac.uk/courses/acv/matlab_demos/fft_image_demo.html> About half way down: F = fft...

mer än 12 år ago | 0

Answered
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...

mer än 12 år ago | 1

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Answered
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...

mer än 12 år ago | 0

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

mer än 12 år ago | 2

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Answered
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...

mer än 12 år ago | 0

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

mer än 12 år ago | 1

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Answered
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...

mer än 12 år ago | 0

Answered
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)...

mer än 12 år ago | 0

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Answered
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...

mer än 12 år ago | 0

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Answered
Scaling of fft output?
See my answer here: <http://www.mathworks.com/matlabcentral/answers/15770-scaling-the-fft-and-the-ifft> In order to conse...

mer än 12 år ago | 0

Answered
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 ...

mer än 12 år ago | 0

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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...

mer än 12 år ago | 0

Answered
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...

mer än 12 år ago | 0

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Answered
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));

mer än 12 år ago | 2

Answered
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) ...

mer än 12 år ago | 4

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Answered
Can my integration code for an accelerometer data work for a Square wave?
Instead of trying to convert using your code, try mine located here: <http://www.mathworks.com/matlabcentral/answers/21700-fi...

mer än 12 år ago | 0

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Answered
Help With Plot Legend
If you are just trying to apply the 3 legend strings to 3 lines on a plot, then all you need to do is: legend(cell) Take...

mer än 12 år ago | 0