Python <-> Julia Bridge¶
In [1]:
%load_ext julia.magic
julia_version = %julia VERSION
julia_version
Initializing Julia interpreter. This may take some time...
Out[1]:
<PyCall.jlwrap 0.5.2>
In [2]:
%%julia
@pyimport matplotlib.pyplot as plt
@pyimport numpy as np
In [3]:
%%julia
# Note how we mix numpy and julia:
t = linspace(0, 2*pi,1000); # use the julia `linspace` and `pi`
s = sin(3*t + 4*np.cos(2*t)); # use the numpy cosine and julia sine
fig = plt.gcf() # **** WATCH THIS VARIABLE ****
plt.plot(t, s, color="red", linewidth=2.0, linestyle="--", label="sin(3t+4.cos(2t))")
Out[3]:
[<matplotlib.lines.Line2D at 0x7f331c95f390>]
In [5]:
import numpy as np
fig = %julia fig
x = np.arange(0, 6, 0.01)
fig.axes[0].plot(x, np.sin(x), '--', label='sin')
fig.axes[0].set_title('A weird Julia function and Fib')
fig.axes[0].legend()
fig
Out[5]:
In [6]:
from __future__ import print_function
# julia fib function
jlfib = %julia _fib(n, pyfib) = n <= 2 ? 1 : pyfib(n-1, _fib) + pyfib(n-2, _fib)
def pyfib(n, _fib):
"""
Python fib function
"""
#print('(P', end='')
if n <= 2:
r = 1
else:
#print('(J', end='')
# here we tell julia (_fib) to recurse using Python
r = _fib(n-1, pyfib) + _fib(n-2, pyfib)
#print(')',end='')
#print(')',end='')
return r
fibonacci = lambda x: pyfib(x, jlfib)
fibonacci(10)
Out[6]:
55