rk_adaptive

rk_adaptive ((expr, vars, vars_initval, var,) — Function

startval, endval, params1…)

Tries to solve the ODE whose derivates are defined by expr to the variables vars, starting at their initial values vars_initval. The independent variable (in physics: normally time) is var, being stepped from startval to endval.

Sometimes it speeds up the calculation to use a floating-point number as startval, as using floars will prevent all results from becoming endless rational numbers.

The following optional parameters are accepted:

maxstep=num: The maximum step size to be used.

minstep=num: The minimum step size to be used.

timestep_initial=num: The initial guess for the optimum time step to start with.

maxabserr=num: The maximum absolute error of the resulting curves.

maxrelerr=num: The maximum relative error of the resulting curves as a fallback for variables with big values for which maxabserr might be too sensitive.

See also rk.

Example:

maxima
(%i1) pnts:rk_adaptive(-1/10*x,x,1,t,0,100)  $

See also: rk.