Risposto
Time interation error while trying to solve a partial differential equation which describes pore diffusion resistance combined with with surface kinetics.
One error, one problem: The error: qr = De; must be replaced by qr = 1; because the boundary condition is given by p+q*f =...

quasi 2 anni fa | 0

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Numerical differentiation and integration
t = [0,5:10:115]; s = [0, 4892.3, 14041.3, 22371.3, 29926.1, 36764.4, 42965.4, 48634.8, 53910.3, 58961.8, 63981.6, 69165.5, 74...

quasi 2 anni fa | 0

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error in runge kutta -Unable to perform assignment because the left and right sides have a different number of elements.
You always have to use the variables at the ith time step, not the complete array in the assignments. I didn't check your compl...

quasi 2 anni fa | 0

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How to plot the temperature unit which is small circle raised at the left of C upper case?
Maybe by adding the interpreter ? In R2024b, your title is correctly plotted without any modifications. x=0:0.1:1; y=x.^2; pl...

quasi 2 anni fa | 0

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The method of how to calculate the FWHM.
xmax = 0; ymax = 4; x = xmax:0.01:3; f = -x.^2 + ymax; FWHM = 2*interp1(f,x,ymax/2) Or directly use the inverse function of...

quasi 2 anni fa | 0

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Risposto
How to make my code run faster
Maybe your system does not have a solution. sol = fsolve(@fun,[1 1 0.1]); fun(sol) sol = 1./sol function equations = fun(par...

quasi 2 anni fa | 0

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Finding more than one root for nonlinear equation
Equations (5) and (6) are two linear equations in q_t, beta and q_dot_b. Use them to express q_t and beta as linear functions o...

quasi 2 anni fa | 0

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How would I Solve this System of Trigonometric Equations for Inverse Kinematics?
Solve eqn2 for t1 Insert the result for t1 in eqn1 and solve for t2 Insert the result for t2 in eqn3 and solve for d1

quasi 2 anni fa | 0

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How to convert a fourth-order ordinary differential equation into a system of first-order ordinary differential equations in order to solve it.
If all conditions are given at x = 0, it's an easy problem: Define z(x) = integral_{x'=0}^{x'=x} d*sqrt(1+y'(x')^2) dx' The ...

quasi 2 anni fa | 1

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How can I correctly implement this Meijer G-function in MATLAB for the given equation with specific parameters ?
a,b,gamma,y1 and y2 are given as numerical values ? Then use a = ...; b = ...; ggamma = ...; y1 = ...; y2 = ...; a1 = -y1...

quasi 2 anni fa | 0

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Risposto
How to solve a five equations systems to get the five unknown
Directly use the five experimental values (T_exp,theta) as numerical data and "lsqcurvefit" or "fmincon" to solve for the five u...

quasi 2 anni fa | 0

Risposto
piece wise function for thermal properties in PDE solver
When creating the geometry for your problem, I'd already take into account these two spatial regions where the different thermal...

quasi 2 anni fa | 0

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Risposto
Netwon algorithm with backtracking is failing
rng('default') n = 2; m = 20; c = sym('c',[n 1]); A = sym('A',[m n]); b = sym('b',[m 1]); x = sym('x',[n 1]); f = c.'*x - ...

quasi 2 anni fa | 0

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Averaging specified number of points around the minimum value
data(ix-5:ix-1) are the 5 points left to the minimum, data(ix+1:ix+5) are the five points right to the minimum. So the code sho...

quasi 2 anni fa | 1

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Risposto
Can anyone help me to run this coding?
OdeBVP returns NaN for ff(3) at the start (see above). You will have to find out the reason (initial values for y, x, parameters...

quasi 2 anni fa | 0

Risposto
Trying to create code which solves a BVP using a second-order finite difference scheme and Newton-Raphson method
% Code to calculate the solution to a % nonlinear BVP with Dirichlet and Robin BCs % Some physical parameter. mu = 10; % De...

quasi 2 anni fa | 0

Risposto
finding the value at a specific time from second-order ODE
The easiest (maybe slightly inaccurate) way is to use interpolation: f_conv = interp1(time,x,2.5) f_ode45 = interp1(time,y(:,1...

quasi 2 anni fa | 2

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Inverse fft doesn't match analytical formulation
syms w F = 1/w^2; ifourier(F); disp(char(ans))

quasi 2 anni fa | 1

Risposto
How do I convert symbolic values to numerical for uitable ?
syms x f = x^2-2; xsol = solve(f==0) class(xsol) xvpa = vpa(xsol) class(xvpa) xnum = double(xsol) class(xnum)

quasi 2 anni fa | 0

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Risposto
I am getting the error message "unable to find symbolic solution" using dsolve.
What exactly am I doing wrong? Nothing. "dsolve" is simply not able to find an analytical solution because the problem is too ...

quasi 2 anni fa | 0

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I keep getting the "not enough inputs error" and I don't know how to fix it
m1 = 135; m2 = 30.3455; w1a = .220; w1w = .780; w1m = .000; w2m = .202; w2w = .798; w2a = .000; syms x [6 1]; F(1) = w1...

quasi 2 anni fa | 0

Risposto
Nonlinear constraints depend on the output of optimization objective
Define the constraints using a lower bound of 0 for x(1) (you can prescribe this in the array lb) and one linear constraint (you...

quasi 2 anni fa | 1

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Risposto
Solving ODE with explicit equations
If you have a mixture of differential and algebraic equations, you need to define the mass matrix appropriately. In your case -...

quasi 2 anni fa | 1

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Error in running the Example script of pdepe
As you can see, the code runs under MATLAB R2024b (and should be no problem under R2023b, too). I suggest contacting Technical ...

quasi 2 anni fa | 0

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Risposto
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...

quasi 2 anni fa | 0

Risposto
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...

quasi 2 anni fa | 0

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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.

quasi 2 anni fa | 1

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Risposto
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 % ...

quasi 2 anni fa | 3

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

quasi 2 anni fa | 0

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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) ...

quasi 2 anni fa | 0