def roots(self):
""" Return the zeros of the spline.
Restriction: only cubic splines are supported by fitpack.
"""
k = self._data[5]
if k == 3:
z, m, ier = dfitpack.sproot(*self._eval_args[:2])
assert ier == 0, ` ier `
return z[:m]
raise NotImplementedError, "finding roots not supported for non-cubic splines"
def roots(self):
""" Return the zeros of the spline.
Restriction: only cubic splines are supported by fitpack.
"""
k = self._data[5]
if k==3:
z,m,ier = dfitpack.sproot(*self._eval_args[:2])
assert ier==0,`ier`
return z[:m]
raise NotImplementedError,\
'finding roots unsupported for non-cubic splines'
def roots(self):
""" Return the zeros of the spline.
Restriction: only cubic splines are supported by fitpack.
"""
k = self._data[5]
if k == 3:
z, m, ier = dfitpack.sproot(*self._eval_args[:2])
if not ier == 0:
raise ValueError("Error code returned by spalde: %s" % ier)
return z[:m]
raise NotImplementedError('finding roots unsupported for '
'non-cubic splines')
def roots(self):
""" Return the zeros of the spline.
Restriction: only cubic splines are supported by fitpack.
"""
k = self._data[5]
if k==3:
z,m,ier = dfitpack.sproot(*self._eval_args[:2])
if not ier == 0:
raise ValueError("Error code returned by spalde: %s" % ier)
return z[:m]
raise NotImplementedError('finding roots unsupported for '
'non-cubic splines')
def sproot(tck,mest=10):
"""Find the roots of a cubic B-spline.
Description:
Given the knots (>=8) and coefficients of a cubic B-spline return the
roots of the spline.
Inputs:
tck -- A length 3 sequence describing the given spline (See splev).
The number of knots must be >= 8. The knots must be a
montonically increasing sequence.
mest -- An estimate of the number of zeros (Default is 10).
Outputs: (zeros, )
zeros -- An array giving the roots of the spline.
See also:
splprep, splrep, splint, spalde, splev - evaluation, roots, integral
bisplrep, bisplev - bivariate splines
UnivariateSpline, BivariateSpline - an alternative wrapping
of the FITPACK functions
"""
t,c,k=tck
if k != 3:
raise ValueError, "Sproot only valid for cubic bsplines"
try:
c[0][0] # check if c is >1-d
parametric = True # it is
except TypeError: parametric = False # c is 1-d
if parametric:
return map(lambda c,t=t,k=k,mest=mest:sproot([t,c,k],mest),c)
else:
if len(t)<8:
raise TypeError,"The number of knots be >=8"
c = c.copy()
c.resize(len(t))
z,m,ier=dfitpack.sproot(t,c,mest)
if ier==10:
raise TypeError,"Invalid input data. t1<=..<=t4<t5<..<tn-3<=..<=tn" \
"must hold."
if ier==0: return z[0:m]
if ier==1:
print "Warning: the number of zeros exceeds mest"
return z
raise TypeError,"Unknown error"
