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how can i change the dimension of the matrix?
You must first decide where you want element (i,j,k) of the old matrix be placed in the new matrix. But usually MATLAB's "resha...

4 years ago | 0

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how to calculate a difference of function with any parameter
function main h = 1e-6; xleft = -pi; xright = pi; n = 200; dx = (xright-xleft)/n; x = xleft:dx:xright; chan...

4 years ago | 0

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Answered
Hi, I have an optimization question that should be solved with the constraints which are written. λ is a constant greater than one and ρ is total power budget that we have.
Solution is simple: rho1 = rho, rho2 = 0.

4 years ago | 0

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the projected distances between the line and edge A
You will have to check for correctness: % Project p1 on plane ABC (gives point p1-proj) Mat = [(B-A)*(B-A).' , (B-A)*(C-A).';(...

4 years ago | 0

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Coding a system of differential equations
Numerically solving the original system will make difficulties because of the singularity at t=0 for y. So let's first rewrite ...

4 years ago | 0

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Product of vector elements where the vector has a large size
Product_V = exp(sum(log(V(1,:)))/numel(V))

4 years ago | 0

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The output of ode45 does not make much sense
function main n0 = 1.0; %assume value for n(0) epsilonmax0 = 10; %assume value for epsilonmax x0 = ...

4 years ago | 0

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Runge kutta 4 probelm
function main g = 9.81; m = 71; k = 1000; l_0 = 8; tstart = 0.0; tend = 10.0; h = 0.01; T = (tstart:h:te...

4 years ago | 1

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One of the constant input variable need to be changed based on previous step's output in ODE, Can anyone kindly help?
Either you insert some delay elements (PT1 or similar) or you have to solve a delay differential equation (e.g. using dde23).

4 years ago | 0

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Given an equation and data points, find the best fit coefficients of the equation
x = 0:5; y = [1 3 9 27 81 243]; A = [ones(6,1),exp(x.')]; b = y.'; a = A\b; f = @(x) a(1)+a(2)*exp(x); plot(...

4 years ago | 0

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Answered
Why is ySol(t) = Dsolve(ode,cond) wrong? What should it be instead?
syms Cs t y(t) ode = diff(y,t) == 40*Cs-40/280*y; cond = y(0) == Cs; ySol(t) = dsolve(ode,cond); ysol_num = subst(ySol,Cs,C)...

4 years ago | 1

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Utilizing the Euler Method
In the if-statement in Flight.m, set x3 to x(3,i-1) and calculate the other variables x4,x5,f,u1,u2,u3,V_ver,C_D,Cl and p only f...

4 years ago | 0

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Anisotropic f coefficient for PDE solving
Maybe page 2-79 under http://uk.mathworks.com/help/pdf_doc/pde/pde.pdf ?

4 years ago | 0

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how to solve this motion equation?
function main y0 = [0 pi/2 0 pi/2]; %[y1 y2 y3 y4]=[theta1 theta1dot theta2 theta2dot] tspan = [0 144*pi]; [T,Y] = ode...

4 years ago | 0

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How can I solve this differential equation?
function main %% defining parameter P = [80;120;100;80;120;80;120;100;80;120;80;80;100;120;100]; % Pressure, bar T = [8...

4 years ago | 0

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Solve a system of ODEs with varying coefficients
function dyds_x = xcomp(sx, yx, s, kappa, tau) kappax = interp1(s,kappa,sx); taux = interp1(s,tau,sx); dyds_x = zeros(3,1);...

4 years ago | 0

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Euler and FD method
function main v=10^4; % cm/s D=2; %cm c=0.099; %cm^-1 b=0.097; %cm^-1 dx=1; %cm Diffrence for x dt=0.248; a=50; %cm ...

4 years ago | 0

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Problems with the application of Newton's method
function main %UNTITLED Summary of this function goes here % Detailed explanation goes here x0 = 20; maxiter = 200; tol =...

4 years ago | 1

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select a range of coefficients of a polynme
What do you mean by "gives me coefficient from 1" ? If you want to suppress the coefficient of x1^5, use c = coeffs(Polynome)...

4 years ago | 0

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Answered
How to write the linear equations in the form of matrix
If you want it fast, you will have to define the matrix once by hand. Number the unknowns U1 = u_{0,0}, U2 = u_{0,1},...,U(N+1...

4 years ago | 0

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Solving a system of ODEs whose coefficients are piecewise functions
function main T = []; Z = []; z0=[0.001 0.001]; tspan1 = [-10 -1]; iflag = 1; [t,z] = ode45(@(t,z) systode(t,z...

4 years ago | 0

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How to solve a system of integro differential equation using numerical method?
function main tspan = [0 10]; y0 = [1; 1; 0; 0]; [T,Y] = ode45(@fun,tspan,y0); plot(T,[Y(:,1),Y(:,2)]) end function dy =...

4 years ago | 0

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Interpolating various dimension matrix
F = scatteredInterpolant(x(1,1:54),x(2,1:54),y(1,1:54)); y_q = F(x_q(1),x_q(2))

4 years ago | 0

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Answered
Writing an equation in terms of specific variables where relationship is known.
syms m a b t r t_eq = solve(r - a*b*t^2==0,t); r = a*b*t^2; F = m * diff(r,t); F = subs(F,t,t_eq)

4 years ago | 0

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Answered
Write a MATLAB implementation that applies the classical fourth order RK method
Here is your corrected code: B=4; f1=@(t,u,v) v; f2=@(t,u,v) 5*exp(-2*t)-2*exp(-(B+2)*t)+exp(-(B*t))+t-v*exp(-B*t)-u; f_exac...

4 years ago | 0

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Answered
Find the roots of a complicated expression
syms x expr_orig = -190 + 100/(1+0.01+x) + 80/(1+0.02+x)^2 + 20/(1+0.03+x)^3; expr = expr_orig*(1+0.01+x)*(1+0.02+x)^2*(1+0.03...

4 years ago | 0

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How can I get output in terms of x and y?
syms u v x y z S = solve([x==u+v,y==exp(v)],[u v]) x = u+v; y = exp(v); z = log(x^2-2*y); dz_du = diff(z,u) dz_dv = diff(z...

4 years ago | 1

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I can not solve 6e quation 6 unkonwn problem.
You have a linear system of equations in the unknowns T1,T2,T3,T4,T5 and T6. So you can put it in the form A*T = b with a 6x...

4 years ago | 1

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Fourier Series Expansion of a Periodic Square Wave
n = 49; fun = @(t) 4/pi*sum(sin((1:2:n)*t)./(1:2:n)); T = linspace(0,2*pi,100); X = arrayfun(fun,T); plot(T,X)

4 years ago | 0

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5 equations in 5 unknowns with fsolve
This code starts running although producing Inf and NaN values: function main P0 = rand(5,1); P = fsolve(@myfun,P0) end f...

4 years ago | 0