Dimension mismatch for using Runge Kutta 4 order methods

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Phong Pham
Phong Pham 2012-8-15
No longer available
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Walter Roberson
Walter Roberson 2012-8-15
When you encounter the problem, what are the size() of k1, k2, k3, k4 ?
Walter Roberson
Walter Roberson 2012-8-16
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回答（1 个）

Kye Taylor
Kye Taylor 2012-8-15
If dx/dt = [0,0,.4,0] for a vector x, then the exact solution is
x(t) = [x0, x1, 0.4*t+x2, x3]
where x0,x1,x2,x3 are initial conditions (position).
Is func really indepenent of t and x(i)?
The issue with your code is that func will return a row vector, but x(:,1) is intialized as a column vector. Then the right-hand-side defining x(:,2) is column vector plus row vector -- this produces an error.
It is because func seemingly returns a row vector, independent of its inputs size or value, that your code is actually working. Perhaps there is more to func?

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