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Apply Dirichlet BC on Vertex
Is there a way to use a function and logic (example below) to have the code use Neumann on edges 1 & 4 but when x=xmax and y=ymi...

1 year ago | 0

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Answered
I have a problem with 2D heat conduction develop a computer code to solve the 2D heat conduction equation:∂2T /∂x2 + ∂2T/ ∂y2 = 0, gradient don't change when iterations increase, please help me
The maximum gradient is always in the left and right upper corner point with value (1-0)/(1/40) = 40. So it won't change in the ...

1 year ago | 1

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Answered
How to solve a thermal model? NEED HELP!!
I get these curves with your equations and your data. T0 = 298.15; T_air = 293.15; G_air = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 22...

1 year ago | 0

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quadgk AbsTol/RelTol parameters combinations
umin = 1e-16; f = @(t,u) exp(-t*u.^2)./(u.*(besselj(0,u).^2+bessely(0,u).^2)); g = @(u) pi/2 * atan((2*double(eulergamma)-log(...

1 year ago | 0

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Solve not returning values after first iteration?
You overwrite omega3 and omega4 as symbolic variables with numerical values. Replace % Solve the system sol = solve([eq1, eq2...

1 year ago | 0

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BVP unknown parameter 2 column vector
You forgot to include "C_L_aoa" as global variable in the script part of your code. clear all clc close all %%%%%%%%%%%%%%%%...

1 year ago | 1

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Answered
Nonlinear Curve fitting with integrals
This code works for your supplied data: Delta = 0.075; delta = 0.002; D = 0.098E-9; gamma = 2.675E8; Rmin = 0.01e-6; Rmax ...

1 year ago | 0

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Answered
How to graph coupled differential equations
% Parameters m1 = 4.0; m2 = 6.0; L = 1.5; k = 100.0; % Added missing parameter g = 9.81; F0 = 100; tF = 1; % Initial st...

1 year ago | 0

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Nonlinear Curve fitting with integrals
It takes too long to run the code online - try if it produces reasonable results. Maybe you have to set lower and upper bounds f...

1 year ago | 0

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Matlab function that tells the full path of from where the function has been called
What about passing the full path where the function is located from the respective functions 2,3,4,5... to function1 ? See htt...

1 year ago | 0

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how to deal with discontinuities in solutions to differential equations using ode45
Usually, the differential equations to be solved are much more complicated than yours which makes it impossible to foresee possi...

1 year ago | 2

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Answered
How to rename a new matrix obtained by adding a row to the previous matrix
A = [1:5; 6:10] B = [A;11*ones(1,size(A,2))]

1 year ago | 0

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Answered
eventfunction for stopping solver when output becomes complex doesn't work
Try options = odeset('Events', @(t,y)stop(t, y, Vb0, lambda, mb, rhog0, Cw)); [t, y] = ode45(@(t, y) DE(t,y, Vb0, lambda, mb,...

1 year ago | 0

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Drawing Bessel function is not possible in that it give me an error
Maybe this is what you want: x=(0:0.01:5).'; i=0:20; hold on for m=0:5 j=sum((-1).^i./(factorial(i).*gamma(i+m+1)).*(x/...

1 year ago | 0

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Answered
Facing problems in nonlinear system
"pdepe" gives a different solution than your method. Maybe the nonlinear systems have multiple solutions. %%%% Problem_01 %%%% ...

1 year ago | 0

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Answered
How to code a 1D ODE in MATLAB
Usually, the equation reads dW/dt + U*dW/dx = C (1) If U in this equation is positive, your flow goes from left to right,...

1 year ago | 0

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Answered
lsqcurvefit Surface Fitting Troubleshooting
There is a problem with your "poly_fun". You have to use poly_fun = @(c,XY) c(1)*XY(:,:,1).^1 + c(2)*XY(:,:,2).^1 + c(3)*XY(:,:...

1 year ago | 2

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Answered
I have this system of linear equations and i need to solve it for unknowns. how i can solve it in MATLAB? we have 8 unknowns and 8 equations.
@javeria If you want to avoid writing your system as A*X = B, you can use a nonlinear solver like "fsolve". As the system is l...

1 year ago | 0

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Finding one real solution with vpasolve
lambda = vpasolve(LCG/B*1/lambda_t==0.75-1/(5.236*CV^2/lambda_t^2+2.4) == 0, lambda_t, [0,inf]);

1 year ago | 0

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make function from matrix
t = linspace(0,10,3000).'; a = rand(3000,1); f = @(x)interp1(t,a,x); f(8.336)

1 year ago | 0

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I am struggling to format and run a pde as part of a liquid-liquid packed column
K_M = 0.1252; xb_meth = 0.0054; Rho_FAME0 = 0.915; Phid_cho = 0.2352; Vd = 6.1006e-4; kod_meth = 1.0157e-5; ap = 204; Vc ...

1 year ago | 0

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Answered
trouver un angle avec l'equation de trajectoire d'un projectile
x0 = 0.08; y0 = 0.05; v0 = 2; g = 9.81; syms t x theta eqn1 = x == v0*t*cos(theta) + x0; eqn2 = 0 == v0*t*sin(theta) - 0.5...

1 year ago | 0

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using bvp5c evaluate velocity and temperature at specific points
yeval = deval(S,[-1,-0.4,0,0.4,1]); veval = yeval(1,:) thetaeval = yeval(2,:)

1 year ago | 0

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Answered
Verifying my code for this problem, are these the right solution and graphs?
Look at the contour plot. The temperature at x = 0 should be at T_b = 50°C. This is not the case in your graphics. Maybe you int...

1 year ago | 0

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Optimization method based on the Nonlinear least squares as well as fmincon for the defined objective function (Non-linear function).
You can add a multiple of the vector you obtain by the below command "double(null(A))" to "estimated_T", and you will still get ...

1 year ago | 0

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Error in ode45 and 'Events' of a Satellite Tracking Radar Model
The "tspan" vector you provide for "ode45" has no influence on the internal time steps taken by the integrator. In zones with st...

1 year ago | 0

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I have been trying to derivate equation under to find the formula for 3 parameters Weibull distribution as same as picture. Can someone please help me fix it?
This code works, but it will not give you the result you want. syms m sigma_i sigma_0 sigma_th i N lnL = symsum(log((m/sigma_0...

1 year ago | 0

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How to vectorize analytical derivative functions for bvp4c?
Only the computation of the vector-valued derivatives function f can be vectorized, not the computation of its analytical deriva...

1 year ago | 0

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Answered
can't run applyBoundaryCondition
"applyBoundaryConditions" is used for general PDE models. You want to use the "thermal" model. The available properties and ob...

1 year ago | 0

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pdepe boundary condition help!!
Note that the f you define in "pdefun" doesn't fit the formula from the paper. You forgot to multiply both terms with m_d/lambda...

1 year ago | 0

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