I'm using Python 3.6 and trying to run the following code which is from here:
from __future__ import division
import numpy as np
import matplotlib.pyplot as plt
import scipy.interpolate
x = np.array([ 2., 1., 1., 2., 2., 4., 4., 3.])
y = np.array([ 1., 2., 3., 4., 2., 3., 2., 1.])
plt.plot(x,y, label='poly')
t = np.arange(x.shape[0], dtype=float)
t /= t[-1]
nt = np.linspace(0, 1, 100)
x1 = scipy.interpolate.spline(t, x, nt)
y1 = scipy.interpolate.spline(t, y, nt)
plt.plot(x1, y1, label='range_spline')
t = np.zeros(x.shape)
t[1:] = np.sqrt((x[1:] - x[:-1])**2 + (y[1:] - y[:-1])**2)
t = np.cumsum(t)
t /= t[-1]
x2 = scipy.interpolate.spline(t, x, nt)
y2 = scipy.interpolate.spline(t, y, nt)
plt.plot(x2, y2, label='dist_spline')
plt.legend(loc='best')
plt.show()
But it generates an error, AttributeError: module 'scipy.interpolate' has no attribute 'spline'.
Then I modify to the following by import make_interp_spline from scipy.interpolate:
from __future__ import division
import numpy as np
import matplotlib.pyplot as plt
import scipy.interpolate
from scipy.interpolate import make_interp_spline
x = np.array([ 2., 1., 1., 2., 2., 4., 4., 3.])
y = np.array([ 1., 2., 3., 4., 2., 3., 2., 1.])
plt.plot(x,y, label='poly')
t = np.arange(x.shape[0], dtype=float)
t /= t[-1]
nt = np.linspace(0, 1, 100)
x1 = make_interp_spline(t, x, nt)
y1 = make_interp_spline(t, y, nt)
plt.plot(x1, y1, label='range_spline')
t = np.zeros(x.shape)
t[1:] = np.sqrt((x[1:] - x[:-1])**2 + (y[1:] - y[:-1])**2)
t = np.cumsum(t)
t /= t[-1]
x2 = make_interp_spline(t, x, nt)
y2 = make_interp_spline(t, y, nt)
plt.plot(x2, y2, label='dist_spline')
plt.legend(loc='best')
plt.show()
I get an new error ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all().
Out:
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-9-2b54020d8fb1> in <module>
12 t /= t[-1]
13 nt = np.linspace(0, 1, 100)
---> 14 x1 = make_interp_spline(t, x, nt)
15 y1 = make_interp_spline(t, y, nt)
16 plt.plot(x1, y1, label='range_spline')
/usr/local/lib/python3.7/site-packages/scipy/interpolate/_bsplines.py in make_interp_spline(x, y, k, t, bc_type, axis, check_finite)
751
752 # special-case k=0 right away
--> 753 if k == 0:
754 if any(_ is not None for _ in (t, deriv_l, deriv_r)):
755 raise ValueError("Too much info for k=0: t and bc_type can only "
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()
Just wonder how to fix this issue? Thank you.
