#Script to illustrate how to draw direction field with supplied command
#draw_dirfield().

#Define right side of ODE u' = f(t,u)
def f(t,u):
    return t*cos(u) - sin(t)

#Load in command
load('draw_dirfield.sage')

#Construct phase portrait on range 0 <= t <= 5, 0 <= u <= 5.
draw_dirfield(f, [0,5,0,5])

#Construct phase portrait with solutions satisfying u(1) = 2, u(2) = 3,
#and u(3) = 1
draw_dirfield(f, [0,5,0,5], [[1,2],[2,3],[3,1]])