Answered
Fsolve and initial guesses
You already received several responses for this question here: https://uk.mathworks.com/matlabcentral/answers/1973704-interpret...

3 years ago | 1

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Find value at which a line changes its slope
Plot gradient(y)./gradient(x) over x to get an approximation of the derivative of your curve and see if this curve can give you ...

3 years ago | 1

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Why do i keep on receiving the same error? Please show me how to fix the code!
Your function "predprey" must return a row vector, not a column vector: Use function yp = predprey(t, y, a, b, c, d) yp = [a ...

3 years ago | 0

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Answered
Check ode45 for a certain value and start a new solver when these limitations are reached
That's exactly what the Event facility of the ODE integrators does. Look at the "ballode" example: https://uk.mathworks.com/he...

3 years ago | 1

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Answered
Error using fmincon line 619
Why do you solve a linear optimization problem with "fmincon" ? Use "linprog" instead. R = [120.97, 462.26, 231.65, 140.94, 26...

3 years ago | 1

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MatLab Multiple graphs in one axis
That your measurement curves overlap and those in the literature don't is a fact. You won't be able to hide this by any special...

3 years ago | 0

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How to do a Taylor expansion with a matrix
Maybe you mean: G = [0,4;4,0]; Gexp = expm(G) or syms t G = [0,4;4,0]*t; Gexp = simplify(taylor(expm(G),t,'ExpansionPoint'...

3 years ago | 1

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Answered
How to use Runge-Kutta orde 4 in sigmoid equation. I want to plot sigmoid equation with Runge kutta orde 4th but my graph is linear. I need help
Why do you use a method for ordinary differential equations to integrate a simple function of the independent variable ? Use "...

3 years ago | 0

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Interpreting the results of 'fsolve'
Can I trust the variable solutions that is computed for me? An error norm of 0.000177715 is not bad, but "fsolve" couldn't do b...

3 years ago | 0

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Answered
Show more than plot at the same time
help figure https://uk.mathworks.com/help/matlab/ref/figure.html help subplot/tiledlayout https://uk.mathworks.com/help/matla...

3 years ago | 0

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Nested differentiation in nested integral
I would (without mathematical scruple) differentiate with respect to "r" under both integrals, then use "integral2" to integrate...

3 years ago | 0

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Answered
How would I remove multiple specific elements from an array.
Data = [923 916 932 927 908 931 953 926 919 963]; B = sort(Data,'ascend'); n = numel(B); xmin = B(1); xmax = B(n); Q1 = rou...

3 years ago | 0

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Trying to apply a general exponential fit to data
As written in the output from CFtool: x is normalized by mean 9.301 and std 6.055. Thus, for x in the equation, you have to ins...

3 years ago | 0

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Answered
Vectorizing Loops over Matrix Elements
If the function f "knows" how to cope with two vectors as inputs that don't have the same size: Yes. E.g. n = 3; m = 5; f = ...

3 years ago | 0

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Answered
hello. how I create function?
You should ask the authors of the code why they didn't include the function "checkHexagonal". Maybe these are the additional fu...

3 years ago | 0

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Fsolve with different combinations of parameters
Varying the initial values for the unknown variables should be the first step. Try "MultiStart". Varying parameters is usually ...

3 years ago | 0

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Answered
Matlab unable to find symbolic solutions for an ode
Do you mean diff(- FgE + FgM + Ft,t) instead of diff(t)*(-FgE + FgM + Ft) ? Because diff(t) does not make much sense to me. If ...

3 years ago | 0

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how to solve a system of linear equation in matlab for gridded data
As said, you can't estimate z and a separately. Say you have y = z + a and data for y. Say you get z = 4 and a = 2 as solutio...

3 years ago | 1

Answered
Error using odearguments due to vector incoherent
Use dxdl=[dx1dl;dx2dl;dr1dl;dr2dl;dTdl]; instead of dxdl=@(l,x) [dx1dl;dx2dl;dr1dl;dr2dl;dTdl]; But nothing will be plotted ...

3 years ago | 1

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Answered
Fourth order nonlinear DE solution where forcing function interpolation is known
You will have to use bvp4c, not ode45. And interpolation in the function where you define the derivative function can be done v...

3 years ago | 0

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Answered
Empty sym: 0-by-1 in solving a system of equations
MATLAB is correct: your system has no solution. You have a linear system of equations, and the vector of the right-hand side is ...

3 years ago | 0

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Answered
Surf a function with different values
Define the function as f = @(x,y) (y>=2*x) + 2*(y<2*x); and make a surface plot.

3 years ago | 0

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Answered
symbolic substituiton with logical operators
syms B L m = [0 0 3;1 2 0]; m = sym(m); idx = m > 1; m(idx) = B; m = subs(m,1,L)

3 years ago | 1

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Answered
How to code multiple "if" conditions in app designer?
if a < b < c does not work. You have to split the condition in two: if a < b & b < c And if a = b does not work. A logic...

3 years ago | 0

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the loop is not converging it is giving me an infinite value(it is increasing)
Why do you think your fixed-point iteration should converge ? If the absolute values of the eigenvalues of A were all < 1, it ...

3 years ago | 1

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graph of iterative sequence
Add the command plot(1:n+1,x) at the end of your code.

3 years ago | 0

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Answered
Solving system of 4 equation
Try "fsolve": e0 = [e10;e20;e30;e40]; % initial guesses for i = 1:25 fun = @(e1,e2,e3,e4) [((nco+v3*e1+v22*e2+v41*e4)^2...

3 years ago | 0

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Time dependent InternalHeatSource where the heat input is in a vector.
Is there a way to pass a vector of heat inputs and the PDE solver using the same time steps as specified in my time vector? No....

3 years ago | 1

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Answered
how do i properly code a formula with multiple summations in matlab?
% parameters: M_array = 1:100; % Number of BS antennas SNR0_dB = 0; % SNR of the desired UE (in dB) SNR0 = 10.^(SNR0_dB/10...

3 years ago | 0

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Answered
Problem with solving an ODE
Use bcfcn = @(ya,yb)[ya(1)-(5+ya(2)*2)/0.49;yb(2)-1]; instead of bcfcn = @(ya,yb)[ya(1)-y0;yb(2)-1]; in your code.

3 years ago | 0

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