def akima_interp(xpt, ypt, x):
"""convenience method for those who don't want derivatives
and don't want to evaluate the same spline multiple times"""
p0, p1, p2, p3 = _akima.setup(xpt, ypt, delta_x=0.0)
npt = len(xpt)
zeros = np.zeros((npt-1, npt))
y, dydx, dydxpt, dydypt = _akima.interp(x, xpt, p0, p1, p2, p3,
zeros, zeros, zeros, zeros, zeros, zeros, zeros, zeros)
return y
def interp(self, x):
"""interpolate at new values
Parameters
----------
x : array_like
x values to sample spline at
Returns
-------
y : nd_array
interpolated values y = fspline(x)
dydx : nd_array
the derivative of y w.r.t. x at each point
dydxpt : 2D nd_array (only returned if delta_x != 0.0)
dydxpt[i, j] the derivative of y[i] w.r.t. xpt[j]
dydypt : 2D nd_array (only returned if delta_x != 0.0)
dydypt[i, j] the derivative of y[i] w.r.t. ypt[j]
"""
x = np.asarray(x)
try:
len(x)
isFloat = False
except TypeError: # if x is just a float
x = np.array([x])
isFloat = True
if x.size == 0: # error check for empty array
y = np.array([])
dydx = np.array([])
dydxpt = np.array([])
dydypt = np.array([])
else:
y, dydx, dydxpt, dydypt = _akima.interp(
x, self.xpt, self.p0, self.p1, self.p2, self.p3, self.dp0_dxpt,
self.dp1_dxpt, self.dp2_dxpt, self.dp3_dxpt, self.dp0_dypt,
self.dp1_dypt, self.dp2_dypt, self.dp3_dypt)
if isFloat:
y = y[0]
dydx = dydx[0]
dydxpt = dydxpt[0, :]
dydypt = dydypt[0, :]
if self.delta_x == 0.0:
return y, dydx
else:
return y, dydx, dydxpt, dydypt
def interp(self, x):
"""interpolate at new values
Parameters
----------
x : array_like
x values to sample spline at
Returns
-------
y : nd_array
interpolated values y = fspline(x)
dydx : nd_array
the derivative of y w.r.t. x at each point
dydxpt : 2D nd_array (only returned if delta_x != 0.0)
dydxpt[i, j] the derivative of y[i] w.r.t. xpt[j]
dydypt : 2D nd_array (only returned if delta_x != 0.0)
dydypt[i, j] the derivative of y[i] w.r.t. ypt[j]
"""
x = np.asarray(x)
try:
len(x)
isFloat = False
except TypeError: # if x is just a float
x = np.array([x])
isFloat = True
if x.size == 0: # error check for empty array
y = np.array([])
dydx = np.array([])
dydxpt = np.array([])
dydypt = np.array([])
else:
y, dydx, dydxpt, dydypt = _akima.interp(x,
self.xpt, self.p0, self.p1, self.p2, self.p3,
self.dp0_dxpt, self.dp1_dxpt, self.dp2_dxpt, self.dp3_dxpt,
self.dp0_dypt, self.dp1_dypt, self.dp2_dypt, self.dp3_dypt)
if isFloat:
y = y[0]
dydx = dydx[0]
dydxpt = dydxpt[0, :]
dydypt = dydypt[0, :]
if self.delta_x == 0.0:
return y, dydx
else:
return y, dydx, dydxpt, dydypt
def akima_interp(xpt, ypt, x):
"""convenience method for those who don't want derivatives
and don't want to evaluate the same spline multiple times"""
p0, p1, p2, p3 = _akima.setup(xpt, ypt, delta_x=0.0)
npt = len(xpt)
zeros = np.zeros((npt - 1, npt))
y, dydx, dydxpt, dydypt = _akima.interp(x, xpt, p0, p1, p2, p3, zeros,
zeros, zeros, zeros, zeros, zeros,
zeros, zeros)
return y
