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# David Goodmanson

### David Goodmanson

Last seen: Today Active since 2012

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How to plot the magnitude and the phase of this function f(1/z)=(0.5 + 000i)*z^(−1 )+ (0.2500 − 0.4330i)*z^(−2) + (−0.2500 − 0.4330i)*z^(−3)?
Hello Aisha, technically this equation should read f(z)=(0.5 + 000i)*z.^(−1 )+ (0.2500 − 0.4330i)*z.^(−2) + (−0.2500 − 0.4330i...

2 días ago | 0

How to Plot Ramsey Phase Plane
HI ec, There are a couple of issues here. First, the cdot expression lacks a dot, should be k.^(alpha-1). Second, the grid ...

5 días ago | 0

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How the plot of the phase of the complex function look likes BY USING THE MATLAB?
Hi Aisha, Taking the second part first, a phase angle can be either positive or negative. The Matlab angle function uses the u...

9 días ago | 0

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Analytical solution for 1D heat equation
Hi Dominick, you have the sum of two sine terms for the boundary condition, sin(x) and (1/10) sin(10x). So consider a general ...

17 días ago | 0

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Why is 0 and 30 1/2?
Hi Alexander; This occurs because heaviside(-.3:.1:.3) ans = 0 0 0 0.5000 1.0000 1.0000 1.0000 ...

17 días ago | 0

Difference between numerical and analytical solution of ode?
Hi IG, Here is an almost-analytical solution for x0 and x1 (which are called x and y respectively). It's analytic for x, uses ...

29 días ago | 0

I want to plot an implicit equation
Hi mohd, This is not really an implicit equation since Vgs appears only once, by itself, on the lhs. So you can take all the o...

alrededor de 1 mes ago | 1

Circular Cross Correlation 2D Using FFT
Hi Ziv, yes, it works similarly. m = 5; n = 6; q = 4; A = randi(m,n,q); B = randi(m,n,q); C = zeros(size(A)); for j = 1:...

alrededor de 1 mes ago | 0

How to get coefficients for second degree polynomial with only two given boundary conditions (means with two equations but with three coefficients)?
Hi Ankit, x = [ 0 1 2 3]; E = [0 1 4.5 10.5]; c = polyfit(x,E,2) % fit a quadratic E1 = polyval(c,x) figure(1) plot(x,...

alrededor de 1 mes ago | 0

Is there any way to plot values that are exponent multiples of 10 as colorbar directly without having to take their log
Hi Mathan, The colorbars cover the same range in each case, but It's still apples and oranges. Consider the value 1e6 In log sp...

alrededor de 2 meses ago | 1

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Can anyone help me? How can I solve 4th order Ordinary differential equations (ODEs)?
Hi Jihweon, Fortunately the analytic solution is pretty straightforward. Denoting Sp by A, the A^-4 factor matches up with the...

alrededor de 2 meses ago | 1

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Getting complex value for real integration
Hi Mithun, One of the more straightforward methods is to forget about symbolics and just write down the solution for y. The el...

alrededor de 2 meses ago | 0

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finding the maxima/minima using lagrange mutlipliers
Hi Ikenna, Here is one way. If you plot the function on the ellipse th = linspace(0,2*pi,1000); xx = cos(th); yy = sin(th)/...

alrededor de 2 meses ago | 0

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Unitary matrix with non-orthogonal eigenvectors?
Hi Joshua, I believe this happens because W has at least one set of degenerate eigenvalues, and does not happen if all the eige...

alrededor de 2 meses ago | 0

Complex output after applying inverse fourier transform
Hi Brian, I beleive the result is due to asymmetric truncation of the image in the frequency domain. I am inferring that your ...

alrededor de 2 meses ago | 0

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Split array into subarrays
Hi David, if A is 200x1 the easiest way to do that is B = reshape(A,50,4) so now B is a matrix whose four columns are each 50...

alrededor de 2 meses ago | 1

How solve this problem in Matlab
Hi Davide, here is a method that uses one for loop instead of two: n = 5 m = 6 V = zeros(n,m); V(:,1) = 1:n; for k = 2:m ...

alrededor de 2 meses ago | 0

trigonometric equation solution help
Hi Giuseppe Although Matlab can't come up with an analytic solution with symbolics, you can still obtain a numerical solution t...

2 meses ago | 0

Efficient way of performing operation on array after performing cumsum
Hi Valentina, A = [1 2 3; 4 5 6; 7 8 9]; B = cumsum(A,2); C = (1:3).\B This gives the result that you show in your question....

2 meses ago | 1

Finding peak value of distorted sine wave signal with varying phase shift of harmonics
Hello Haroon, This answer addresses the first part, getting a maximum or "minimum-at-maximum" value. It's a lot easier to do t...

2 meses ago | 0

How to use syms to solve system of equations?
Hi NIcholas, This can be done without using syms. Syms of course can be slow, and the result in this case is a typically ponde...

2 meses ago | 2

How can I obtain the analytical expression (polynomial) of the spline curve from a curve fitting?
Hi Radu, x = 1:10; y = sin(x).^3; a = interp1(x,y,'spline','pp') a = struct with fields: form: 'pp' br...

3 meses ago | 0

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sum of a sum of a sum of a sum
Hi Marta, The code below does not address the algebra in the paper, but I am posting this because it is another way of doing th...

3 meses ago | 1

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How can I define proper frequency domain of FFT function in Matlab
Probably a bit late in the game, but the followiing code shows the peak at 300Thz. A couple of issues here: first to (a) get a...

3 meses ago | 0

Best way to get rid of/ prevent function from creating complex numbers?
Hello Jeffrey, Deleting unsatisfactory results is of course not a good way to deal with this. I ran case {15} from your matfil...

3 meses ago | 1

Can I input data with multiple column lengths into one matrix?
Hi Brice, If you preallocate as you mentioned then you can insert each column with t = zeros(300,numslugs); x = zeros(300,num...

3 meses ago | 0

Trying to plot a frequency response (magnitude and angle) using the equation of a forced vibration
Hi Bryanna, The problem statement asks for delta_t of .01, but you have .1 instead. Changing to .01 makes things clearer. The...

3 meses ago | 1

How do I get rid of certain values with the same X-axis value in a certain range?
Hi Michael, here is one way, assuming that x (many values of which are repeated) and y are two columns. tol = 10; a = polyfit...

3 meses ago | 0

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