Scilab Function

portr3d - 3 dimensional phase portrait.

### Calling Sequence

  `[]=portr3d(f,[odem,xdim,npts,pinit])`

### Parameters

- `f` : 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
  - `odem` : gives the integration method to use. The value "default" can be used, otherwise see ode for a complete set of possibilities
  - `npts` : 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])
  - `xdim` : [xmin,xmax,ymin,ymax,zmin,zmax] the boundaries of the graphic frame.
  - `pinit` : 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)].

### Description

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 )

### See Also

`ode` ,