def check_sproot(self):
a=0
b=15
N=20
x=a+(b-a)*arange(N+1,dtype=float)/float(N)
v=f1(x)
k=3
uspl = UnivariateSpline(x,v,k=k,s=0)
ex = array([0.0, pi, 2.0*pi, 3.0*pi, 4.0*pi])
assert_array_almost_equal(uspl.roots(),ex, decimal=3)
