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I'm trying two solve two ode using ODE 45 ,But it shows some error,How to call multiple functions in ode 45?
w0=[w10;w20]; [t,w]=ode45(@ODE,T,w0); w1=w(1); w2=w(2); 1st possibilty: function dx=ODE(t,w) ...

8 years ago | 0

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Answered
I'm trying two solve two ode using ODE 45 ,But it shows some error,How to call multiple functions in ode 45?
Put the two ODEs in one function, not in two. Or use one driver function "ODE" to be called by the integrator and call "ODE1"...

8 years ago | 0

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Fitting the numerical solution of a PDE with one parameter to some data
https://de.mathworks.com/matlabcentral/answers/43439-monod-kinetics-and-curve-fitting The procedure can easily be adapted to w...

8 years ago | 0

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I have four equations and four variables, I need to assume value of one variable, calculate the rest and then back-calculate the first variable till the assumed and calculated value converges. How do I do this using while?
a = 2; a1 = 1; k = 0 ; while abs(a-a1) > 1e-8 a = a1; b = a + 2; c = a + b + 1; d = a - b + c; ...

8 years ago | 0

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Error using integral (line 85) A and B must be floating point scalars. Error in hawt3 (line 30) Torque(i)= integral(fun,'r',a1,b1);
close all clear all Vwind=10; BladeRadius=40; % aoa=5 deg TSR=[2 3 4 5 6 7 8 9]; Numblades=3; n= leng...

8 years ago | 0

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solution of coupled first order odes numerically
Use the mass matrix option of the ODE solvers. Or explicitly solve your equations for diff(var1) and diff(var2) (2 linear equ...

8 years ago | 0

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How can I do the best fit of a power function with my original data
xdata = ...; ydata = ...; a0 = 1/2.33; fun = @(a)sum((ydata-xdata.^a).*xdata.^a.*log(xdata)); a = fzero(fun,a0) ...

8 years ago | 0

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Error using fzero (line 306) FZERO cannot continue because user-supplied function_handle ==> @(x)((x(i)/gemmai(i))*(exp(D(i)/x(i))-1)+x(i)-C(i)) failed with the error below. Index exceeds array bounds. Error in abc (line 6) y=fzero(fun,12);
fun=@(x)((x/gemmai(i))*(exp(D(i)/x)-1)+x-C(i));

8 years ago | 0

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Answered
two coupled first oredr ODE plot
% Constant parameters DeltaE = 0 ; omega = 0.1 ; kesi = 8e-5 ; Omega = 1e-2 ; q = 1e-5 ; % Initial ...

8 years ago | 0

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Answered
Solving homogeneous systems of linear equations
If I execute A=[ 5529.6571965113201121628855218102,-3000 -3000, 1627.5873313951778400904919565612]; null(A)...

8 years ago | 0

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Convolution of a CDF and a PDF
ANOF=@(t)-log(1-integral(@(y)wblcdf(t-y,100,2).*normpdf(y,2.2,0.1),0,t,'ArrayValued',true)); ANOF(50) ANOF(100) Best ...

8 years ago | 0

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Integration of a function
function main A=...; B=...; C=...; fun=@(t,y)A*(1-y(1)/B)*exp(C*y(1)); tspan=[0 1]; y0=0; ...

8 years ago | 0

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Singular Jacobian with BVP4c used to solve eigenvalue problem
Use a=(a small value) instead of a=0. Best wishes Torsten.

8 years ago | 1

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bvp4c setup for second order ODE
sol = bvp4c(@(x)odefcn(x,D_ij,k_1,k_2,k_3,d_1,d_2,d_3,K_1,K_2,K_3,K_4,K_i,N_T),@twobc,solinit);

8 years ago | 0

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how to solve the below error
function main timespan=[0 15]; y0 = [0 1 0 1 0 1]; [t,y] = ode45(@repressilator,timespan,y0); figure() plot(t,...

8 years ago | 0

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Solve an equation with 3 variables
https://de.mathworks.com/help/matlab/ref/fimplicit3.html Best wishes Torsten.

8 years ago | 0

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Answered
How to solve an integral with symbolic values as borders in another integral?
Use integral2: scale = 0.00095; shape = 8.907; lambda = 0.00174; func1 = @(x) (wblpdf(k_1t-tr+x,1/scale,shape))/(1...

8 years ago | 0

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CurveFitting given only derivative
You don't need to put a derivative in lsqcurvefit since there is an analytical solution for your ODE from above: https://www....

8 years ago | 0

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I have a system of nonlinear equations an i would like to use a genetic algorithm to solve it .How do i go about it.
function res= TRIAL3(x,V1,W1,W,w,z,Z1,Z,p,p1,q1,q,c1,V,v,j) a=[x(1);x(2);x(3);x(4);x(5)]; r=[x(6);x(7);x(8);x(9);x(10)];...

8 years ago | 0

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Porblem to use Symprod for exponential product
lambda=2*10^-4; R_th=[27.23 32.65 15.23 18.02 10.25 32.20]; R_2=[14.25 11.02 10.99 1.25 9.36 40.35]; a=lambda.*...

8 years ago | 0

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Answered
How to solve an ODE which has a parameter that is obtained from solving a different ODE?
Instead of solving for x1-x4 and z1-z3 separately, solve both systems together as one. This way, you get rid of defining u and i...

8 years ago | 0

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I am trying to use the fsolve function to solve a non linear equation .In the function i created all the constants are matrices.and i expect a vector of the unknown.I keep getting error of not enough input argument.Iwould much appreciate your help.
fun = @(x)TRIAL3(x, V1,W1 ,W, w, z, Z1,Z, p, p1, q1, q, c1, V, v, j); Xo = [1 1 1 1 1 1 1]; X = fsolve(fun,Xo)

8 years ago | 0

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Answered
how can i plot "L(1) L(2)*cosd(t) -
xi=...; xf=...; L = [... ;... ;...]; T = xi:0.1:xf; J = zeros(numel(T),1); for i=1:numel(T) t = T(i); ...

8 years ago | 1

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Please help a student: How can you estimate these 5 parameters by using nonlinear least squares?
1. p0 has 6 elements, but you only use 5 paramters. This should be modified. 2. In the last term of the denominator, replace ...

8 years ago | 1

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Answered
fitting a 3-parameter of Weibull PDF using mle
custpdf = @(data,a,b,c) (data>c).*(b/a).*(((data-c)/a).^(b-1)).*exp(-((data-c)/a).^b); opt = statset('MaxIter',1e5,'MaxFunE...

8 years ago | 0

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Answered
how I Found the minimum of function using the fminbnd ??
You can't. fminbnd is for functions of one variable - your f is a function of two variables. Use "fmincon" instead. Best w...

8 years ago | 0

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Solve command in matlab not working?
Setting L*F*DMR = a, you can see that in reality, you don't have 4 equations in 4 unknowns, but only 4 equations in 2 unknowns. ...

8 years ago | 1

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Answered
Two-level Recurrence in Matlab
You could try to insert the solution expression for b(n) in the calculation for a(n). Another way: <https://www.wolframalp...

8 years ago | 0

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Solving a set of equations with PDEPE for PSA
Total mass balance, Energy balance for walls, Mass transfer rate and Ergun equation don't fit in the scheme of pdepe. Thus y...

8 years ago | 0

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Plotting a function defined by a system of ODEs
tspan = [0 100]; z0 = [0.01 0.01 0.01 0.01]; [t,z] = ode45(@(t,z) odefun(t,z), tspan, z0); z1 = (t+1).*z(:,1); plo...

8 years ago | 0

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