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2
votes
0answers
50 views

The idea behind Stiffness switching method with NDsolve [closed]

Does the Stiffness switching method with NDsolve switch just between multiple variants of 4th order Runge Kutta method or it uses also other methods?
0
votes
0answers
75 views

Using Mathematica to solve a recursive system of differential equations

I believe I have a difficult problem to work on specially because I don't have any previously experience using Mathematica in this kind of situation. So I'll try to describe it as best as I can hoping ...
3
votes
1answer
115 views

OutputResponse in V9 vs V10

I have same code that works in version 9.0.1, but not in version 10.0.1.0 (according to @Sektor, it works in 10.0.0.0, too). ...
1
vote
1answer
199 views

Is it possible to give the closed-form of the stiffness matrix of triangular prism element?

Suppose the vertices of triangular prism are 1, 2, 3 (bottom triangle), 4, 5, 6 (top triangle), the coordinates of the vertices are $$ (x_i, y_i, z_i), i=1,2,3,4,5,6. $$ We can write the stiffness ...
0
votes
0answers
44 views

How to generate closed-form stiff matrix of triangular prism element by mathematica [duplicate]

We can generate closed-form stiff matrix of tetrahedron by mathematica: http://library.wolfram.com/infocenter/Articles/3233/ Can we also generate closed-form stiff matrix of triangular prism element ...
1
vote
1answer
995 views

shooting method and stifness problem for NDSolve

I'm trying to solve numerically the following differential equation: 1/r[x]^5 + k/Sqrt[1 + r'[x]^2] - (k r[x]r''[x])/(1 + r'[x]^2)^(3/2) == 0 I can set boundary ...
9
votes
1answer
723 views

How to solve a stiff nonlinear second-order ode?

I want to solve a nonlinear second order ODE as an initial value problem (IVP). Unfortunately, for certain values of first derivative at starting point I get a stiff-problem. I tried to overtake this ...
1
vote
1answer
185 views

Changing ParametricNDSolveValue options for only part of the run

Here is an example of the system that I am running, ...
1
vote
0answers
1k views

NDSolve: methods and step size choosing

I am looking into the documentation of NDSolve[]; more precisely how this function chooses the StepSize and how it chooses which ...