Scilab Function fchamp - direction field of a 2D first order ODE
Calling Sequence
- fchamp(f,t,xr,yr,[arfact,rect,strf])
- fchamp(f,t,xr,yr,<opt_args>)
Parameters
- f
: An external (function or character string) or a list which describes the ODE.
- -
It can be a function name f, where f is supposed to be a function of type y=f(t,xy [p1,..pn]). f returns a column vector of size 2, y, which gives the value of the direction field f at point xy=[x,y] and at time t.
- -
It can also be an object of type list, list(f,P1,..Pn) where f is a function of type y=f(t,xy,p1,..pn) and Pi gives the value of the parameter pi.
- t
: The selected time.
- xr,yr
: Two row vectors of size n1 and n2 which define the grid on which the direction field is computed.
- <opt_args>
: This represents a sequence of statements key1=value1, key2=value2,... where key1, key2,... can be one of the following: arfact, rect, strf (see below).
- arfact,rect,strf
: Optional arguments, see champ.
Description
fchamp is used to draw the direction field of a 2D first order ODE
defined by the external function f. Note that if the ODE is autonomous,
argument t is useless, but it must be given.
Enter the command fchamp() to see a demo.
Examples
deff("[xdot] = derpol(t,x)",..
["xd1 = x(2)";..
"xd2 = -x(1) + (1 - x(1)**2)*x(2)";..
"xdot = [ xd1 ; xd2 ]"])
xf= -1:0.1:1;
yf= -1:0.1:1;
fchamp(derpol,0,xf,yf)
xbasc()
fchamp(derpol,0,xf,yf,1,[-2,-2,2,2],"011")
See Also
Author