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How can I solve coupled nonlinear hyperbolic equations?
CLAWPACK available under https://www.clawpack.org/ is an excellent solver for hyperbolic systems of differential equations. A...

4 years ago | 0

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How to add integral in a integral function
format long integral(@(x)sin(integral(@(a)sin(a),0,x)),0,1,'ArrayValued',true) integral(@(x)sin(1-cos(x)),0,1)

4 years ago | 0

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why while loop repeats so long?
If you output "count" for the numerical solution, it's about 14000. Now if you measure the time for one symbolic iteration in ...

4 years ago | 0

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Answered
vector and for-loop issues in ode solver
%Parameters input.n=10; % # in r input.Ea=63000; % [J/mol] input.R=8.314; % [J/mol/K] input...

4 years ago | 0

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Answered
Basis function regression for 3 parameters
Put the equations y(x1(i),x2(j),x3(k)) = a_0*f_0(x1(i), x2(j), x3(k)) + a_1*f_1(x1(i), x2(j), x3(k)) + a_2*f_2(x1(i), x2(j), x3...

4 years ago | 0

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Eigenvalues in symbolic matrix
Replace %% 2.stability analysis J=jacobian([gp(1)*vp(1)./(kp(1)+N0)*N*P1 - mp(1)*P1^2==0, ... gp(2)*vp(2)./(kp(2)...

4 years ago | 0

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Answered
sum of Bessel function
m = 0:250; x = linspace(-5*pi,5*pi,1000).'; A = 2./((2*m+1)*pi).*besselj(0,pi/2*m).*sin(1000*(2*m+1).*x-(2*m+1)*pi/2); f = su...

4 years ago | 0

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Finite difference temperature distribution with TDMA
You solve the system iteratively. But you were told to solve it with the Thomas-Algorithm. So apply this algorithm to the matrix...

4 years ago | 0

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Answered
How to solve a system of 8 equations having integrals!
d0 = ones(1,8); d = fsolve(@fun,d0) norm(fun(d)) function res = fun(D) d=1.18; E=27000000; L=121.53; I=(pi*d^4)...

4 years ago | 1

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Answered
In fmincon I set the linear constraint x1+x2+x3=12, but the sum of decision variables in the iteration result does not meet the condition
Tighten your ConstraintTolerance, and you'll see that fmincon converges to an infeasible point for n=12 and n=13. 1st： (main.m)...

4 years ago | 2

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Answered
unable to plot RungeKutta trajectory graph, potentially initial conditions?
Your code produces NaN values for z(1,:) and z(3,:), most probably caused by thetad and thetav. alpha = pi/4; tend = 2; v0 = ...

4 years ago | 0

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bvp4c/bvp5c error
Did you create a function with name "eps" ? Then you should rename it because "eps" is an internal MATLAB function.

4 years ago | 0

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Answered
How to solve f'(x)=0?
You want to find x symbolically or numerically ? Numerically use "fzero". Symbolically use "solve".

4 years ago | 0

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Trying to find area under my plot
https://de.mathworks.com/matlabcentral/answers/514107-how-to-find-area-enclosed-by-a-closed-curve To get the positive and negat...

4 years ago | 0

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I want to use a matrix and a function to then create another function
theta1 = -50; theta2 = 30; theta3 = 15; theta4 = -75; theta5 = -45; theta6 = -60; DH = [theta1, 486.5, 150, -90;... ...

4 years ago | 0

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Solving system of 9 nonlinear equaitons in 16 variables
x0 = -10*ones(16,1); AB = [13 15 -1;9 24 0;7 2 35]; options = optimset('TolFun',1e-16,'TolX',1e-16); x = fmincon(@(x)fun(x,AB...

4 years ago | 2

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Answered
the same value resulted from the linear optimization problem
You define w(k)=beta(k)*(-k_(k) *w_k(k)-k_(k)*log2(lamda(k)*(1-tau^2))*Pt + 2*k_(k)*log2(sqrt(segma_squared))-v_k(k)); and w...

4 years ago | 0

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Hello guys, I need to solve this system of nonlinear symbolic equation; the variables known are X,Y,Z and I already know the solution for q1; so I just need to find q2 and q3.
syms d1 d5 a2 a3 a4 q1 q2 q3 X Y Z % Square eq1 and eq2, add both sides of the equations and take sqrt % Check for other solu...

4 years ago | 0

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Answered
What's the simplest way to determine the mass of a sphere from a plot of its density varying in r?
If r and rho are column vectors where r is ordered as r(1) < r(2) < ... < r(n) and rho is the density at position r, an approxim...

4 years ago | 2

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Answered
Index exceeds the number of array elements. Index must not exceed 1.
Pb is a scalar. So Pb(ii) does not exist. You can use Fbump(ii)=Pb/VA(ii); %this line of code is givig me the error but I don...

4 years ago | 0

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Erro in calling function using horner()
I don't understand what you intend by using the lines [pz,b] = horner(a,x); [dpz,b]= horner(b,x); [pz ,a] = horner(a,x) The...

4 years ago | 0

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Answered
Solving an integral when the parameters is a matrix - Controllability Gramian
You mean syms t t0 tf A = [0 1 0 0;0 0 -4.91 0;0 0 0 1;0 0 73.55 0]; B = [0;2;0;-10]; [M,J] = jordan(A); phi_s=M * expm(J...

4 years ago | 0

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Answered
sum of Bessel function
syms x syms m integer A = 2/((2*m+1)*pi)*besselj(0,pi/2*m)*sin((2*m+1)*1000*x-(2*m+1)*pi/2) g = symsum(A,m,0,Inf) fplot(g...

4 years ago | 0

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Solving Laplace equation using Finite difference
If L = 3 and H = 1, you cannot choose the same number of points in x and y direction if you update U as if you use a grid with e...

4 years ago | 0

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solve matrix differential equations with ode45
syms t y1(t) y2(t) A = [0 1;8 -2]; Y = dsolve(diff([y1;y2],t)==A*[y1;y2]) y1 = Y.y1; y2 = Y.y2; diff(y1,t)-y2 diff(y2,t)-8...

4 years ago | 0

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How do I use meshgrid and quiver3 in a system of differential equations?
https://web.sha1.bfh.science/Labs/F2/ODE/VectorFields.pdf

4 years ago | 0

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How can I solve this matrix question using for loop?
Not the most efficient solution, but maybe best to understand what's happening. A=[0 0 0 ;6 5 7;12 14 30;35 40 42;75 55 50;85 6...

4 years ago | 0

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Answered
myfunction not working when applied on a meshgrid
x= 0:0.01:2*pi; %629 element. y= 0:0.001:1; %1001 element. [X, Y]= meshgrid(x,y); z=zeros(1001,629); %% for X and Y are bot...

4 years ago | 1

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Answered
How to find the actual value of d,b,t and D in the maximum value of sac?
close all clear all clc % Constants c = 340; % Speed of sound rho = 1.204; % ...

4 years ago | 0

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Need to solve this with Runge-Kutta 4th order method in MatLab.
fy=@(x,y,z) z; fz=@(x,y,z) (1-y^2)*z-y; x(1)=0; z(1)=0; y(1)=1; h=0.1; xfinal=10; N=ceil((xfinal-x(1))/h); for j=1:N ...

4 years ago | 0

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