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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...

presque 12 ans il y a | 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...

presque 12 ans il y a | 3 réponses | 1

3

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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; ...

presque 12 ans il y a | 0

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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...

presque 12 ans il y a | 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...

presque 12 ans il y a | 1

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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...

presque 12 ans il y a | 0

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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...

presque 12 ans il y a | 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 ...

presque 12 ans il y a | 0

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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...

presque 12 ans il y a | 0

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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...

presque 12 ans il y a | 0

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[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 ...

presque 12 ans il y a | 1

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

presque 12 ans il y a | 0

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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...

presque 12 ans il y a | 0

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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...

presque 12 ans il y a | 0

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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...

presque 12 ans il y a | 1

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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...

presque 12 ans il y a | 0

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

presque 12 ans il y a | 2

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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...

environ 12 ans il y a | 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...

environ 12 ans il y a | 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...

environ 12 ans il y a | 0

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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)...

environ 12 ans il y a | 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...

environ 12 ans il y a | 0

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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...

environ 12 ans il y a | 0

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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 ...

environ 12 ans il y a | 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...

environ 12 ans il y a | 0

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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...

environ 12 ans il y a | 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));

environ 12 ans il y a | 2

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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) ...

environ 12 ans il y a | 4

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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...

environ 12 ans il y a | 0

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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...

environ 12 ans il y a | 0

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