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How to find spectrum envelope from wav file
Hilbert Transformation is used to obtain the envelope of signal, here is an example : The envelope is decreasing exponential...

10 years 前 | 0

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Identifying wave-number sign after FFT2
The general solution for a wave travelling in the +X direction is, at point X : y(0,t)=A exp(j(wt)) y(X,t)=A exp(j(wt-KX))...

10 years 前 | 1

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about High pass and low pass filter
The syntax for designing low pass filters is : b = fir1(n,Wn,'ftype',window); n is the number of coefficients, Wn is th...

10 years 前 | 0

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How do I graph this plane with three points?
you can use geometric construction with meshgrid function or use patch function as follows : patch([1 1 2],[2 2 1],[3 1 0],0...

10 years 前 | 0

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Wrong "step" function answer
According to the system you described, here the result i obtained : <</matlabcentral/answers/uploaded_files/22588/ST.jpg>> ...

10 years 前 | 0

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Plotting contours of a probability density
You have to use two dimensional arrays of x and z to produce two dimensional pdf, try : [x,z]=meshgrid(-6:0.01:6); r=sqrt...

10 years 前 | 1

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Plotting piece-wise functions with absolute value????
The algorithm you wrote is almost correct, inside the if conditions you need to use x(k), not x : x = linspace (-10,10,100)...

10 years 前 | 0

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Stand alone C file
If you mean reading a file with C, then you need to use pointer as the following, with apriori knowledge of array dimensions : ...

10 years 前 | 0

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Problem in computing the curl of 2D velocity vector field
Generally, the input velocity matrices may contain NaNs, try : sum(isnan(UU(:))); % must be zero if there is no NaN, same fo...

10 years 前 | 0

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matlab triple integral conical gravity
I think that working with symbolic variables will not permit the transformation of integral expressions to numeric type, however...

10 years 前 | 0

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Correlation between two images ..
if you mean correlation coefficient, you can program manually the function or use corr2 : corr2(A,B); % returns a scalar...

10 years 前 | 0

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I can I duplicate raws of variables?
try this standard method a=[1:3]; b=[]; for n=1:6 b=[b a]; end

10 years 前 | 0

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How to apply velocity + acceleration to a position?
@Roger gave the solution (Vx,Vy) . try to write a feedback of this solution. t=0:100e-3:20; V0x=1000; Alpha=0.0004; Beta...

10 years 前 | 0

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已回答
SVD & EVD of a Symmetric Matrix
Floating points problems occur as mentioned by @Jhon, you can verify if your matrix M is symmetric or not : norm(M-M') % mus...

10 years 前 | 0

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How to apply velocity + acceleration to a position?
You can verify this primary solution theoretically : t=0:100e-3:20; V0x=1000; Alpha=0.0004; Beta=0.25; Vx=...

10 years 前 | 0

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Time series syntax question
ts(i,1) means performing calculation of the elements of first column of matrix ts, ts(i,2) means the ith element on the second c...

10 years 前 | 0

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I have a question about RESAMPLE
This is an interesting remark, however in Documentation, it was mentioned that re-sampling has side effect because of filterin...

10 years 前 | 0

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I have a sine function y = a*sin(bx+c)+d and I have 4 points on the function: P1(0.835,0.720) P2(1.498,0.589) P3(2.866,0.236) P4(3.299,0.649)?
hi, if you have Math symbolic ToolBox, you can use the function solve, the output is a structure with symbolic variables : ...

10 years 前 | 0

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Integrating with trapz and calculate the error
The first remark is that names of built in functions must not be used as variables ( trapz in this case ), second remark is *int...

10 years 前 | 0

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Computing first derivative--image processing
In general diff(X,n) of N by 1 vector returns an N-n by 1 vector, second derivative is diff(X,2), using gradient is better beca...

10 years 前 | 0

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Using loglog for plotting a logarithmic graph
You have to use element wise operator ( . before any operator sign) : x = 10:19700; y=96818.90647.*sqrt(55327.8644...

10 years 前 | 0

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How to draw same size rectangle on different image location
Try to adjust this protocol to your problem : L=0.5; N=100; for n=1:N p=randn; p2=randn; r=p+L; r2=p2+L...

10 years 前 | 1

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variance equation of a white noise
you can program E or use *var* function, %var(x,0) %var(x,1)

10 years 前 | 0

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How to add noise to rect fuction (rectangle) ?
The solution exists for one dimensional function, when you apply the function, you obtain a logical array, you need to convert i...

10 years 前 | 0

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how to make fft2 surf plot with z axis in dB?
This problem does not occur with the following test : H=exp(-randn(10).^2); F=abs(fftshift(fft2(H,200,200))); F=F/m...

10 years 前 | 0

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Sine wave changing amplitude
Nuchto, That is the amplitude modulation, it is possible to simulate that type of signals: x=real(exp(j*2*pi*(0:0.1:10))); ...

10 years 前 | 0

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How from uint8 to 0 and 1?
rgb2gray(im2double(X));

10 years 前 | 0

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Draw a polar plot from cartesian plot of gain function
In the code, v is not defined, i assume is it omegat, try : figure; polar(omegat,abs(gainfunction)); % 20*log10(abs(gain...

10 years 前 | 0

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Question about coordinate system in matlab
You can start inspecting the x,y values in sample, to get an idea try : >>imshow('circuit.tif') Then go to *Tools* in men...

10 years 前 | 0

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Help generating a triangle using arrays, rotating triangle
Colin, you can try using the function *line* as the following : x1=[0 2]; y1=[0 0]; x2=[0 0]; y2=[0 1]; x3=[0 2]; ...

10 years 前 | 0