Respondida
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...

casi 10 años hace | 0

Respondida
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))...

casi 10 años hace | 1

Respondida
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...

casi 10 años hace | 0

Respondida
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...

casi 10 años hace | 0

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

casi 10 años hace | 0

Respondida
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...

casi 10 años hace | 1

Respondida
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)...

casi 10 años hace | 0

Respondida
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 : ...

casi 10 años hace | 0

Respondida
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...

casi 10 años hace | 0

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

casi 10 años hace | 0

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

casi 10 años hace | 0

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

casi 10 años hace | 0

| aceptada

Respondida
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...

casi 10 años hace | 0

| aceptada

Respondida
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...

casi 10 años hace | 0

Respondida
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=...

casi 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

| aceptada

Respondida
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 : ...

alrededor de 10 años hace | 0

| aceptada

Respondida
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...

alrededor de 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

| aceptada

Respondida
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...

alrededor de 10 años hace | 1

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

alrededor de 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

Respondida
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))); ...

alrededor de 10 años hace | 0

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

alrededor de 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

Respondida
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...

alrededor de 10 años hace | 0

Respondida
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]; ...

alrededor de 10 años hace | 0