Beantwortet
recreating roots of a derivative of bessel funtion of first order
Hi fv, Here is a function for the first q zeros of both Jn(x) and dJn(x) /dx. As an example, to find the first 100 zeros of th...

11 Monate vor | 1

Beantwortet
Picking Branch Cut of Square Root
Hi bil, Here is a function that does that job. It appears that you want to do the division (a-i)/(a+i) before taking the squar...

11 Monate vor | 2

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Beantwortet
Find the nonzero maximum frequency corresponding to FFT graph.
Hi Zahra, the peak at zero frequency is because your signal does not have average value of zero, but has a DC offset. To elimi...

12 Monate vor | 0

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Beantwortet
Find combination of 12 matrix rows, fulfilling certain criterion, from matrix of size 3432 *7
Hi Ernesto, Once you have a single 12x7 solution you can make many more by random element swapping of elements in that matrix. ...

12 Monate vor | 0

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I know it is a redundant question, but i have no idea why solve keeps returning 0
Hello Andrei, First of all, all these expressions are functions of (x1-x2) and (y1-y2) only. That means if x1,x2,y1,y2 is a so...

fast ein Jahr vor | 2

Beantwortet
atanh of negative complex numbers
Hi Derek, For the troublesome subplot, try semilogx(f,unwrap(imag(2*x*gamma))/(2*x)) The idea is that the phase is proportion...

etwa ein Jahr vor | 0

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Beantwortet
Solving systems of trig equations
Hi Jon, Here is one method. To come up with values of r and g that work, it appears to be easier to think in terms of R = r^2 ...

etwa ein Jahr vor | 1

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Change the period/frequency of a Van der Pol Oscillator
Hi Alexis, If you want to preserve the shape you will have to have a larger set of parameters. I am taking as given your equa...

etwa ein Jahr vor | 0

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Beantwortet
Cconditional subtraction of 2 vectors of different lengths
Hi salah, You can do quite a bit if the two vectors are sorted. Assume you have two sorted vectors sx and sy of length Nx and ...

etwa ein Jahr vor | 0

Beantwortet
Get "Matrix is is singular to working precision" when attempting a global stiffness matrix with four nodes
Hi Declan, I am not sure how you are getting the error message. Running the code with k changed to K d(range) = K(range,range...

etwa ein Jahr vor | 1

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Beantwortet
energy signal
Hi k.v. For a given real signal y(n) of length N, n = 1 to N, the power at any point n is y(n)^2, the average power P is Pave ...

mehr als ein Jahr vor | 0

Beantwortet
How can I evaluate a complex definite integral?
Hi Valentin, It's not strictly necessary (see Paul's vpa solution) but it is advantageous to scale things properly before doing...

mehr als ein Jahr vor | 0

Beantwortet
How to use sinc function
Hi Ricardo, while it might be nice to have the Signal Processing toolbox, you certainly don't need to buy any toolboxes to do t...

mehr als ein Jahr vor | 0

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how to find concave angle between three points
Hi Eliska, One thing that does not seem to be mentioned so far is your use of the norm function on the determinant. That makes...

mehr als ein Jahr vor | 0

Beantwortet
calculation error in hyperbolic function
one possibility: (tanh(-10))^2 ans = 1.0000 % correct although tanh(-(10)^2) % traveling parenthesis ans =...

mehr als ein Jahr vor | 0

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Partial derivative with respect to x^2
Hi Yadavindu, df/d(x^2) = (df/dx) / (d(x^2)/dx) = (df/dx) / (2*x) which you can code up without the issue you are seeing.

mehr als ein Jahr vor | 1

Beantwortet
Solving a system of Non-linear Equations with Complex numbers
Hellol Aravindhan, not solved by Matlab, but a bit of algebra shows that with x(1) = 2000*a x(2) = 2000*b x(3) = theta/5 t...

mehr als ein Jahr vor | 0

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Increasing the caclulation speed while using loops
Hi Hamid, Hi Hamid, I have not speed checked this but it should be faster (the range in your example is different from the draw...

mehr als ein Jahr vor | 2

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Beantwortet
How to introduce a phase shift to a existing vector
I assume that you are given the oscillatory function V in an array, with no accompanying array for the independent variable to s...

mehr als ein Jahr vor | 0

Beantwortet
Average of random variables from two Poisson distributions?
Hi Jonne, I assume you want to look at the distribution for a period of one minute, whenever that might occur. As opposed to l...

mehr als ein Jahr vor | 1

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Beantwortet
How to extrapolate a plot?
What is being fitted is T vs. C, with the idea of extrapolating to T=0. The C variable, C=log((A0-A1)./(A-A1)) contains A, wh...

mehr als ein Jahr vor | 0

Beantwortet
z transfer function evaluates to inaccurate value near z=1
Hi Ashish, This function, ((1-1/z^2)/(1-1/z))^6 is identically equal to ((z+1)/z)^6 so you can just use that. And it does ...

mehr als ein Jahr vor | 0

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Why am I getting wrong spectrum applying FFT comparing with correct spectrum?
Hi Jiang, There are a couple of things going on here. The expression for FFT is not correct. Since you are taking the real pa...

mehr als ein Jahr vor | 0

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Solve system of equations with some knowns and unknowns in the same matrix
Hi Yusuf, I'm later on an answer (and losing the race more often, to the extent that there is a race, which to be honest there ...

mehr als ein Jahr vor | 0

Beantwortet
How can I code a contour integral representation of cosine?
Hi Richard, this integral converges very slowly along the vertical path gamma-i*inf to gamma+i*inf. Convergence depends on wha...

mehr als ein Jahr vor | 1

Beantwortet
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 ...

mehr als ein Jahr vor | 1

Beantwortet
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 ...

mehr als ein Jahr vor | 0

Beantwortet
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...

mehr als ein Jahr vor | 0

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Beantwortet
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...

mehr als ein Jahr vor | 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) = []; ...

mehr als ein Jahr vor | 0