You can treat your equation as a system that happens to have just one dimension, and implement it the same way you would an n-dimensional system. I have attached code that solves the Solow equation (from economics); it is basically the same as the example in the reference manual, but modified for this first order equation. The jacobian is just the derivative of the right-hand side of the equation with respect to the dependent variable (x, in your case; k, for the Solow model).
Warren On Tue, Nov 10, 2009 at 12:09 PM, Earl, Joseph <[email protected] > wrote: > Hi, > > I am trying to solve a first-order ODE of the form > > x' = sqrt(1/3x - k + lx^2) > > using the GSL C++ library, where k and l are constants for a particular > solution. > > I have no problem at all using GSL to solve 2nd order (such as x'' = -x) > and higher ODEs, something is just confusing about the first order equations > and how to put them into the required form. > The Jacobian doesn't seem to make much sense with a 1st order ODE. > > Also the current documentation is pretty poor - there is only one example > of a 2nd order ODE which is repeated all over the net. So if anyone wants to > add a 1st order example to the help docs I'm sure that would be of some use > to others (and me!) in the future. > > Any help would be much appreciated (if you feel like writing out a full > working example that would be awesome). > > Regards, > Joseph Earl > Imperial College London > > _______________________________________________ > Help-gsl mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/help-gsl >
gsl_1d_ode.c
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