def chebfun(f=None, domain=None, n=None):
"""Chebfun constructor
"""
# chebfun()
if f is None:
return Chebfun.initempty()
domain = DefaultPrefs.domain if domain is None else domain
# chebfun(lambda x: f(x), ... )
if hasattr(f, "__call__"):
return _initfun(f, domain, n)
# chebfun('x', ... )
if isinstance(f, str) and len(f) is 1 and f.isalpha():
if n:
return _initfun(lambda x: x, domain, n)
else:
return Chebfun.initidentity(domain)
try:
# chebfun(3.14, ... ), chebfun('3.14', ... )
return Chebfun.initconst(float(f), domain)
except:
raise ValueError(f)
def chebfun(f=None, domain=None, n=None):
"""Chebfun constructor
"""
# chebfun()
if f is None:
return Chebfun.initempty()
domain = DefaultPrefs.domain if domain is None else domain
# chebfun(lambda x: f(x), ... )
if hasattr(f, "__call__"):
return Chebfun.initfun(f, domain, n)
# chebfun('x', ... )
if isinstance(f, str) and len(f) is 1 and f.isalpha():
if n:
return Chebfun.initfun(lambda x: x, domain, n)
else:
return Chebfun.initidentity(domain)
try:
# chebfun(3.14, ... ), chebfun('3.14', ... )
return Chebfun.initconst(float(f), domain)
except:
raise ValueError(f)
def test_initidentity(self):
_doms = (
np.linspace(-1,1,2),
np.linspace(-1,1,11),
np.linspace(-10,17,351),
np.linspace(-9.3,-3.2,22),
np.linspace(2.5,144.3,2112),
)
for _dom in _doms:
ff = Chebfun.initidentity(_dom)
a, b = ff.support
xx = np.linspace(a, b, 1001)
tol = eps * ff.hscale
self.assertLessEqual(infnorm(ff(xx)-xx), tol)
# test the default case
ff = Chebfun.initidentity()
a, b = ff.support
xx = np.linspace(a, b, 1001)
tol = eps * ff.hscale
self.assertLessEqual(infnorm(ff(xx)-xx), tol)
def test_initidentity(self):
_doms = (
np.linspace(-1, 1, 2),
np.linspace(-1, 1, 11),
np.linspace(-10, 17, 351),
np.linspace(-9.3, -3.2, 22),
np.linspace(2.5, 144.3, 2112),
)
for _dom in _doms:
ff = Chebfun.initidentity(_dom)
a, b = ff.support
xx = np.linspace(a, b, 1001)
tol = eps * ff.hscale
self.assertLessEqual(infnorm(ff(xx) - xx), tol)
# test the default case
ff = Chebfun.initidentity()
a, b = ff.support
xx = np.linspace(a, b, 1001)
tol = eps * ff.hscale
self.assertLessEqual(infnorm(ff(xx) - xx), tol)