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reverse lookup table from vector multiplikation with unknown vectors
Hello Henning, Assuming that you want column vectors a and b such that their outer product C = a*b' is as close as possible to ...

1年以上前 | 1

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How to define color on matrix figure
Hi Jan, the following method comes up with black not just for values that are exactly zero (I don't know how likely that might ...

1年以上前 | 0

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Question using IFFT, try to transform continuous 1 from frequency in time domain
Hi Jan, In the secnd example the dirac value should be quite large, In fact it should be 3e5, the number of points, not half o...

1年以上前 | 0

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fminsearch for a function f(x,y) = x^4 -3xy+2y^2
Hi Ibraheem, While it's useful to find out about how to get fminsearch to cooperate, that's hardly necessary here. For the min...

1年以上前 | 0

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Random numbers generation problem
Hi Daniel, here is one way, basically the sieve of Eratosthenes. nmax = 1000; a = randi(nmax,1,1e6); a(rem(a,2)== 0) = []; ...

1年以上前 | 0

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different result of PCA function and my PCA
Hi Farshad, Each column vector in the cof matrix is arbitrary up to an overall constant of absolute value 1, which for the case...

1年以上前 | 0

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My code is outputting very illogical answers for the second block (my second vector loop equation).
Hi Emily, No one seems to have mentioned that there are two independent solutions for the angle pair angle3 and angle4, since i...

1年以上前 | 0

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My code is outputting very illogical answers for the second block (my second vector loop equation).
Hi Emily, If VLE1 and VLE2 are lined up typographically, you have VLE1 = @(x0) [(R2.*cos(theta2_all(i)) + R3.*cos(x0(1)) -...

1年以上前 | 0

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xcorr and finddelay giving erroneous results for offset sine waves
Hi James, This effect is due to a peculiarity in finding delays when your sample is cut off sharply at each end. The following...

1年以上前 | 1

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Would you tell me the code for Fisher Pearson skewness?
Hi Chris, y = rand(1,100); % some data m = mean(y); n = numel(y); scalc = (sum((y-m).^3)/n)/var(y,1)^(3/2) s = skewness...

1年以上前 | 1

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Why doesn't the kurtosis function work properly for complex numbers?
Hi Guillem, Both the standard deviation and the variance (std and var) work correctly for complex argument, so kurtosis appears...

1年以上前 | 1

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SIR model with recovered individuals may lose their immunity and become reinfected with the disease. But came with a failure about integration tolerances
Hi Julian, I have doubts about the equations, because with dq(1) = -S as you have, the equations are equivalent to S = -beta*S...

1年以上前 | 0

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what does the positive and negative values concave mean?.
Hello Aisha, You are looking at a polynomial function of z, with two roots as you stated. To see what is going on, it helps to...

1年以上前 | 0

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Differentiate with Respect to Derivative
Hello Mitra, what version of Matlab are you running? Running your code in 2021b gives D1 = m*diff(x(t), t) as desir...

1年以上前 | 1

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Huge difference between the result of fft function Matlab and analytical Fourier transform of the same function
Hi ST, Your frequency grid runs from -5 to 5, which for an fft is -fs/2 to fs/2 (fs being the sampling frequency), so fs = ...

1年以上前 | 0

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Plotting the theoretical maximum possible efficiency of a heat engine
Hi Aidan, It's possible to fix up the for loop, but easier and much more in the spirit of Matlab to do this with vectors. Tl1=...

1年以上前 | 0

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Compute wave energy converter power output using power matrix
Hi Ross, For the matrices SWH and T02, which I will call S and T, do they already meet the condition S contains integers from ...

1年以上前 | 0

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Finding PSD from Autocorrelation, FFT, Periodogram and Pwelch
Hello YK, Since you are using ffts, the appropriate correlation is going to be circular correlation. This can be done by using...

1年以上前 | 1

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is there any method to apply the for loop in this, I caN't see any pattern please help in this
Hi Sahil, This can be done by for loop but it is maybe better to do the whole thing with index manipulation. In the written-ou...

1年以上前 | 0

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How can I show Electric Potential due to a Dipole as a 3D surface?
Hi Luca, Since you can't show the values of the potential at every point in the 3d space, this is most commonly done by showing...

1年以上前 | 0

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What is the equation used for taylor window function 'taylorwin'
Hi Palguna, The equations are in the attachment. rect(t) is a rectagle function, = 1 for -1/2<= t <= 1/2, 0 otherwise. That's...

1年以上前 | 2

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Explanation for a function within xcorr
Hi big, rather than puzzle this out in place, it seemed easier to look at the output of the function for the first hundred valu...

1年以上前 | 0

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Got wrong normal vector
Hi AC, You were quite right in your suspicions of the 3d plot, which looks fishy. You might call this a configuration control ...

1年以上前 | 0

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fft vs nufft- scaling
Hi Nathan, In the fft case you are dividing by N = 1500 and multiplying by 2. For nufft you aren't doing that. Hence the fact...

1年以上前 | 0

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Why I got the dominant frequency as 1/time when I running fft?
Hi CS, here is an example, first with 800 points, then 400 points. The frequency scale is constructed differently in each one ...

1年以上前 | 0

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finding the orthogonal vectors for a series of vectors
Hi Pouya, Here is another method, somewhat related to Bruno's a = 2*rand(1000,3)-1; m1 = tril(ones(3,3)) -triu(ones(3,3)) ...

2年弱前 | 1

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spline for corner object
HI Mehri, try sorting by angle around a point in the center: x0 = 350; y0 = 325; theta = atan2(y-y0,x-x0); [~,ind] = sort(t...

2年弱前 | 1

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I want to solve this couple differential where the dot represent the derivative with respect to t/tp, where tp = 30E-9, is my code for solving this is correct? ?
Hi Sahil, Since the constants are all of order 10^-3 to 10^3 or so, it's evident that normalized units are in play. So you hav...

2年弱前 | 0

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Write a vectorial function from a scalar function
Hi Giuseppi, it looks like you intend, in this case, f = @(z,y) z.^2 + y^2 Here .^ gives the element-by-element square of z, ...

2年弱前 | 0

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What is the use case for ifft's trailing zero padding? Why is that the default?
Hi Kevin. Zeropaddinig has consequences. It also has its uses, but sometimes the results are unexpected. First of all, whatev...

2年弱前 | 1