portr3d - 3 dimensional phase portrait.
: a Scilab external which gives the field of the dynamical system. Hence it can be a macro name which computes the field at time t and point x [y]=f(t,x,[u]) or a list list(f1,u1) where f1 is a macro of type [y]=f1(t,x,u) or a character string
- .I rest
: The other parameters are optional. If omitted they will be asked interactively
: gives the integration method to use. The value "default" can be used, otherwise see ode for a complete set of possibilities
: a vector of size (2,10) [number-of-points,step] gives the step for integration and the number of requested points. The solution will be calculated and drawn for time=0:step:(step*[number-of-points])
: [xmin,xmax,ymin,ymax,zmin,zmax] the boundaries of the graphic frame.
: initial values for integration. A set of initial points can be given in a matrix
pinit = [x0(1), x1(1),...., xn(1)
x0(2), x1(2),...., xn(2)
x0(3), x1(3),...., xn(3)].
Interactive integration and display of a 3 dimensional phase portrait
of a dynamical system dx/dt=f(t,x,[u]) (where u is an optional parameter )