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hello, kindly help, I am getting the following error why?: Error using bvp4c Unable to solve the collocation equations -- a singular Jacobian encountered. Error (line 7)
Your initial guess of [ 0 0] resulted in NaN values for dydt. The code works now, but the results are weird. You should check y...

3年以上前 | 0

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Solving differential equation using ode45
Here is the solution of your problem for reference: x = linspace(0,1,25); t = linspace(0,2.5,25); m = 0; sol = pdepe(m,@heat...

3年以上前 | 1

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How do I solve this non linear equation that requires user defined inputs for each variable and determine the value of K
syms I I0 Ilim C C0 Kinv eqn = I == I0 + (Ilim-I0)/(2*C0)*((C0+C+Kinv)-sqrt((C0+C+Kinv)^2-4*C*C0)); sol = solve(eqn,Kinv); K ...

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Solve function not returning a zero
syms x y a = 3; b = 4; c = 1; d = 2; g = 2.5; eqn = (sqrt((x-a).^2 + (y-b).^2) - sqrt((x-c).^2 + (y-d).^2)).^2 == g.^2; s...

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how to right math functions
us = @(t) 4*(t>=0 & t<5) + 2*(t>=5); t = -10:0.1:10; plot(t,us(t),'r')

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Solving a system of differential equation using BVP4C but getting error - "The derivative function ODEFUN should return a column vector of length 4."
Replace your function "freq" by function dYdx = freq(x,Y,kGA,EIeff,rhoAom,rhoIom,Fhydro,Mb) Y0 = Y(1); Y1 = Y(2); Y3 = Y(3);...

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SOLVING SYSTEM OF ODEs
Write your three equations in the same independent variable (thus either t or tau). I assume all three equations are written in...

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What does hash X (#X) mean in a system of differential equations solution (dsolve)?
The solution depends on the roots of a polynomial of degree 3. The independent variable of the polynomial is denoted by #X. If ...

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Unable to solve the collocation equations -- a singular Jacobian encountered.
You have an ODE that has a singularity at x=0. Further, solving for D2y leads to two different differential equations. You must ...

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Implementation of 4-step Runge-Kutta
Change the order of the input arguments for f: f = @(t,y) ... instead of f = @(y,t) ...

3年以上前 | 1

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How to perform integration for the following condition?
alpha= (1 + (((H-Z)/H)*(fa-1)))*Kh*sin((2*pi/T)*(t-(H-x_d)/Vs_S)); m = @(z)Gamma*(H-z)*(tan(Beta)+cot(alpha)); K = @(z) alpha*...

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How to solve symbolic function
syms t ap eq=(ap^2*t^3)/2 - ap*t^3 + (ap*t^2)/2 - t^3/2 + t^2/2 + (127*t)/8 - 8 sol=solve(eq==0,'ReturnConditions',true,'MaxDe...

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I am trying to use Events option in ode45 for my program , please help!
Replace val=y(:,3)-1315; by val=y(3)-1315;

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Solving a PDE using PDE Toolbox
C.ri = 0.0125; C.ro = 0.0375; C.alpha = 1.905*10^-5; C.Ti = 673; C.T0 = 573; r = linspace(C.ri,C.ro,50); t = linspa...

3年以上前 | 0

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Solve linear equation in matrix form
Why don't you use pi0 = null((A0+R*B).'); if ~isempty(pi0) pi0 = pi0.'/(pi0.'*inv(I-R)*e) end

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determine the reaction parameter using regression method. i need to know about n, E, A
If you take the logarithm on both sides of your rate equation, you get a linear regression problem. Use \ to solve for the unkno...

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ODE45 to solve multiple degree of system free vibration
Maybe you mean m1=10; m2=10; m3=10; m4=10; k1=50; k2=50; k3=50; k4=50; M=[m1 0 0 0;0 m2 0 0;0 0 m3 0;0 0 0 m4]; K=[k1+k2 -k2...

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How to run please this example perfectly to get optimal solution .. Thank you
f = [0 ; -10 ; 0 ; -6; -20] ; A = [1 0 0 0 0 ; 0 1 0 0 0 ; 0 0 1 0 0 ; 0 0 0 1 0 ; 0 0 0 0 1] ; B = [...

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How to normalize plot?
x0 = -.02:0.001:.02;lambda=532*10^-9; y0 = -.02:0.001:.02;w0 = 0.002; omegax=1;omegay=2;zr=pi*w0^2/lambda; m = 2; s=1;k=0.00...

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How to Double integrate cell of array containing cell of array?
Works. If your problem is more complicated, you will have to include the code as plain text (no graphics) in order to see where ...

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How to produce Gaussian random variable between two vectors ?
sr = [1,2,2,2,3,3,3,4,5]; % various possible source for i = 1:numel(sr) pd{i} = makedist('Normal',0, sqrt(2)); %generate Gau...

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Solving Non-Linear Equations in Matlab by Iteration
First step: Give numerical values to all variables except "taf" Second step: Plot dhO2out+dhN2out+dhCO2+dhH2O - sum (v10) as...

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Problem Calculating Mean of Function
It's obvious that mean(x/y) does not equal mean(x)/mean(y) for arrays x and y. Test it for a simple example.

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Evaluating a function using kramers-kronig relation
syms omega omega0 Omega Gamma real kappa(omega) = 1/(2*pi) * Gamma^2/((omega-omega0)^2 + Gamma^2) ; nR(omega) = 1 + 2/pi*int(O...

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Solving BVP PDE in 3D
Would like to confirm if these are all my options or if there are others. Using MATLAB, these seem to be the only options. And ...

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Solving ODEs with variable updates at a set of discrete time points.
However, this is computationally expensive, and I'm looking for a way to incorporate these variable updates into a single simula...

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I am trying to solve those two coupled differential equations analyticaly or numericaly but I only received errors. I will appreciate any help
An analytical solution of your equations seems hopeless because of the exp(...) term. Use a numerical approach. ico=10; ...

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Error in line 53 when using linear interpolation
The name of the interpolation function is "interp1", not "interpl".

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Array indices must be positive integers or logical values.
You define a variable "length" as length = (3.76*(P/abreast) + 33.2); % Fuselage length in ft This conflicts with the MATLAB f...

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,v1Trying to solve a linear equation matrix with a log of X1-X5 in the matrix. Not sure how to use the log value in simulate to get correct result.
A = [1 0 0 0 0 0.05 0 0 0 0 0;-1 1 0 0 0 0 0.05 0 0 0 0;0 -1 1 0 0 0 0 0.05 0 0 0;0 0 -1 1 0 0 0 0 0.05 0 0;0 0 0 -1 1 0 0 0 0 0...

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