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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...

mehr als 13 Jahre vor | 0

Frage

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...

mehr als 13 Jahre vor | 3 Antworten | 1

3

Antworten

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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; ...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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 ...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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 ...

mehr als 13 Jahre vor | 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.

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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 =...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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 13 Jahre vor | 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 13 Jahre vor | 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)...

mehr als 13 Jahre vor | 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 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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 ...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 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 13 Jahre vor | 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) ...

mehr als 13 Jahre vor | 5

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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...

mehr als 13 Jahre vor | 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...

mehr als 13 Jahre vor | 0