Answered
FFT / IFFT question .
Hi Marcelo, Even if you use 'symmetric' option, you still have to provide the entire frequency vector input. 'symmetric' just ta...

14 years ago | 0

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Answered
estimate the autocorrelation function of white gaussian noise with variance 1
Use randn() to generate the WGN sequence and xcorr() to estimate the autocorrelation sequence. See the help for both functio...

14 years ago | 0

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phase angle from discrte hilbert tranform
Hi Bobby, the derivative of the phase of the analytic signal is the instantaneous frequency that is true. But estimating the ins...

14 years ago | 0

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Answered
phase angle from discrte hilbert tranform
Hi, Do you really just want the phase function, or are you trying to get the instantaneous frequency. At any rate, you can get t...

14 years ago | 0

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Signal filtering
Hi Anna, If you're using reshape you can't change the number of elements. so x = randn(10,1); x1 = reshape(x,5,2); is...

14 years ago | 0

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Answered
Apply filter to sound
Not sure why you want to apply both the Hamming window and use the Butterworth filter. But say you have the Butterworth filter a...

14 years ago | 1

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Answered
How to convert a .tif file into a .mat file?
You can use imread() to read a TIFF file.

14 years ago | 0

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Cross correlation (xcorr) issue
I'm not sure I understand your confusion. You start out saying that you have two datasets that differ in magnitude but follow th...

14 years ago | 1

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Signal Processing Help
Generally the stricter your filter requirements the higher the order. The relationship between any linear time invariant oper...

14 years ago | 0

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Answered
Calculate PSD and plot smooth curve
Hi, you do not want to input test in this example, because test is a matrix. psd() expects a vector input, a 1-D signal. What yo...

14 years ago | 0

Answered
randn, awgn, wgn
Hi, SNR implies that you have a signal, in your call to awgn() you have no signal, just noise. If you use awgn() you should i...

14 years ago | 0

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Calculate PSD and plot smooth curve
Hi, yes, you can just return the output from psd() and plot it as you wish. psdest = psd(spectrum.periodogram,x,'Fs',Fs,'NF...

14 years ago | 0

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Calculate PSD and plot smooth curve
Hi JT, you can use spectrum.periodogram and spectrum.welch Fs = 1000; t = 0:1/Fs:1-1/Fs; x = cos(2*pi*100*t)+randn(si...

14 years ago | 0

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Answered
for loop
This is very similar to your other post: <http://www.mathworks.com/matlabcentral/answers/22660-for-loop-functions> was you...

14 years ago | 0

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using the same varible twice in a calculation
a = 1:10; c =cos(a)./tan(a+20)

14 years ago | 0

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I can't figure out how to use ecmnfish
Hi do you have that product installed? If you enter >>ver Do you see the Financial Toolbox in your installation?

14 years ago | 1

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Answered
generating impulse
Just create a vector of zeros the length you need and then place a 1 at the correct index in the vector. x = zeros(1e3,1)...

14 years ago | 0

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for loop/functions
There's no reason why you can't assign the output of a function to an array % initialize an array A = zeros(100,2); ...

14 years ago | 0

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Signal Processing Help
Hi, you do not need to use ifft(). You do not need to filter the time vector, just the data. output = filter(B,A,data); bu...

14 years ago | 0

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Plotting in 3D in MATLAB
First, you need a .* operator as I told you in my earlier answer. I think you're making it too complicated. Why are you ...

14 years ago | 0

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Cross Correlation - resulting vector not normalized properly? Help!
The 'coeff' option only produces a value of 1 or -1 if a given time shift (lag) results in a perfect positive or negative correl...

14 years ago | 0

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Subscripted assignment dimension mismatch
With the error that you are reporting, I suspect your problem is that your input image does not have X and Y dimensions that are...

14 years ago | 0

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Answered
Signal Processing Help
Hi, You do not want to use filter() on the frequency domain representation of the data. Use filter() directly on the time domain...

14 years ago | 0

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about ECG signal cheek state
You ECG signal is in microvolts. In my experience that is a very small amplitude for ECG. It is definitely a reasonable lev...

14 years ago | 0

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Plotting in 3D in MATLAB
Showing you how to plot this is the whole assignment so it's difficult to help you without simply giving you the answer. Note...

14 years ago | 0

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Answered
Undefined function or method 'fft' for input arguments of type 'sym'.
fft is not overloaded for symbolic inputs. fft() is only for numeric inputs. If you want the Fourier transform of a symbolic inp...

14 years ago | 0

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normxcorr2 function - spatial / frequency domain selection
Hi Sam, normxcorr2 computes an estimate of the computation time for spatial domain correlation vs. frequency domain. Whichever i...

14 years ago | 2

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Answered
error while using complex2real
complex2real is not a MATHWORKS' function. That error message is indicating that MATLAB does not know anything about that functi...

14 years ago | 0

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Answered
Use of PSD functions to obtain FRFs
Hi Craig, one problem is that you use one window for your coherence estimate that is the entire length of your data. This will a...

14 years ago | 1

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Answered
adding a gaussian filter to MSK
Hi Raj, Do you have the Communications System Toolbox? Use comm.GMSKModulator and comm.GMSKDemodulator

14 years ago | 0