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How to optimize an reduce the computation time
I don't understand the sense of your while-loop. If you want to define Psat as a function of fg, the problem becomes more compl...

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How to convert symbolic expression to numeric?
integrand_num = matlabFunction(subs(simplify(integrand))) gives you a function handle with y as input argument (see above). A...

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Concerned that matlabFunction( ), when converting from symbolic to numerical, changes the sizes of matrices and vectors,
As you can see M = reshape([...],[3 3]) Thus the expression in [ ] is 1x9, but it is finally reshaped to 3x3.

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Cannot subtract number of order smaller then e-4 from variable
It's just a question of how the numbers are displayed. Internally, the precision of computing is much higher. format long % ...

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Reduce the size of Matrix from 100x100 to 35x11
x1 = x1(1:35,1:11)

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best combination for lowest possible dose and lowest possible material cost
You mean bestDoseRate = Inf; bestCost = Inf; for index = 2:9261 if (mixDoseRate(index) <= bestDoseRate && mixCost(index) ...

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RK4 help (someone help fix this)
Use for i=1:n_nodes-1 instead of for i=1,n_nodes-1;

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Solving a set of complex trig equation
Do you see the problem ? Your R-values and your y- and z-values are not compatible (at least for n = 3). It must hold that R_v...

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Warning: Non-finite result. The integration was unsuccessful. Singularity likely. > In integral2Calc>integral2t (line 131)
fun(Phi0(1),Phi0(1)) gives NaN + 1i*NaN

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How to solve rachford - race function using newton method
Multiply the equation by product_{i=1}^{n_c} (1+f_Rg*(K_i-1)). This gives you a polynomial of degree n_c-1 in f_Rg which can be ...

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How can I evaluate the transition matrix using the fourth order Runge-Kutta ODEs
If it's still of interest: this code seems to work correctly. I don't know why using n = size(A,1); E = A(t+dt/2)*(eye(n)+dt/2...

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Why do I receive error using BVP5C "The boundary condition function BCFUN should return a column vector of length 1"?
You have one first-order ODE, but two boundary conditions. That's mathematically impossible - you can impose only one condition....

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Event function and ODE.
Don't use both events simultaneously in your event function. Start the solver with the first event function and integrate until...

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Trouble solving system of pdes with pdepe
"pdepe" is a solver for parabolic-elliptic partial differential equations. The positions with zero elements in the f-vector indi...

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Solving the differential equation gives unexpected results. How to fix that?
Better ? v(t) = v(0) - g*t - v0*log(m0/(m0-k*t))

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Define function for transient transient boundary condition
F1= 3.843e-8; F2= -3.482e-5; F3= 1.179e-2; F4= -1.95; F5= 23.69; Trefrig = @(location,state)F1*state.time^4 + F2*state.time...

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How to write an event function to stop at second or third x axis crossing.
I'd make the solver stop at each x-crossing. After it returns control to the calling program, add 1 to the number of crossings a...

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Why don't I need a comment character after an (...) ellipsis?
Most probably there is the convention that ... is the symbol to connect two subsequent lines and that everything behind the ... ...

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AYUDA EN CODIGO DE MATLAB PARA UN ESTRUCTURA DE PUNETE EN 3D
If you insert the lines % Calcular desplazamientos en los grados de libertad libres rank(K_aa) size(K_aa) before the command...

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Why Is Colon Operator Not Equivalent To linspace Command?
Both arrays seem to be generated differently such that floating point issues come into play: z1 = 0:.08:50000; z2 = linspace(0...

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How to draw the function relationship graph between two or three variables, where these variables are solved by a system of equations.
Here are the three possible solutions for VL given tc. % 定义符号变量 VL=20; syms tc t2 Q_out Vco Vcn VL %参数关系 L=100e-9; C=50e-6...

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Plotting a variable versus space and time
Use "slice": https://uk.mathworks.com/help/matlab/ref/slice.html

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checkGradients, but the objective function has two inputs: x and xdata?
valid = checkGradients(@(p)semiCircle(p, Q),p0)

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How can I evaluate the transition matrix using the fourth order Runge-Kutta ODEs
Seems to work. What's your problem ? Don't use the transition matrix to integrate in one pass. If you have to, generate it with...

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problem with vpa and symsum
The numerical bessel functions are not able to compute your sum correctly (for higher values of k, they return NaN) (see below)....

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getting singular jacobian error while using bvp4c solver
I can't interprete your solution curves, but it seems to be a problem for the solver that the Scaled Mass goes to 0 with increas...

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Empty sym: 0-by-1 : Don't understand why
I multiplied by the denominators and squared to get rid of the square roots. Your system seems to have 4 (complex-valued) solut...

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Non-linear least squares estimation with linear constraints in Simulink?
I vaguely remember that using "lsqcurvefit" within Simulink requires to use the Levenberg-Marquardt algorithm. I can't answer wh...

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Do I have a convergence issue?
B0 = 0.5; B = fsolve(@fun,B0) function residual = fun(B) g = 10; %m/s^2 Q = 70*1000; %N/m tau_L1 = 24*1000; %Pa t_w = 30...

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HOw to find displacement integrating velocity?
The equation from above describes the stationary velocity profile over the length L. Thus replacing v by dx/dt does not make sen...

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