The main feature of the ** scipy.special** package is the definition of numerous special functions of mathematical physics. Available functions include airy, elliptic, bessel, gamma, beta, hypergeometric, parabolic cylinder, mathieu, spheroidal wave, struve, and kelvin. There are also some low-level stats functions that are not intended for general use as an easier interface to these functions is provided by the

**module. Most of these functions can take array arguments and return array results following the same broadcasting rules as other math functions in Numerical Python. Many of these functions also accept complex numbers as input. For a complete list of the available functions with a one-line description type**

`stats`

**da me non funziona đĄ Each function also has its own documentation accessible using help. If you donât see a function you need, consider writing it and contributing it to the library. You can write the function in either C, Fortran, or Python. Look in the source code of the library for examples of each of these kinds of functions.**

`help(special)`

,**Bessel**

Bessel functions are a family of solutions to Besselâs differential equation with real or complex order alpha:

Among other uses, these functions arise in wave propagation problems such as the vibrational modes of a thin drum head. Here is an example of a circular drum head anchored at the edge:

Inserisco il codice nel file ** bs.py** che eseguo con

**.**

`python3 bs.py`

`import numpy as np from scipy import special def drumhead_height(n, k, distance, angle, t): kth_zero = special.jn_zeros(n, k)[-1] return np.cos(t) * np.cos(n*angle) * special.jn(n, distance*kth_zero) theta = np.r_[0:2*np.pi:50j] radius = np.r_[0:1:50j] x = np.array([r * np.cos(theta) for r in radius]) y = np.array([r * np.sin(theta) for r in radius]) z = np.array([drumhead_height(1, 1, r, theta, 0.5) for r in radius]) import matplotlib.pyplot as plt from mpl_toolkits.mplot3d import Axes3D from matplotlib import cm fig = plt.figure() ax = Axes3D(fig) ax.plot_surface(x, y, z, rstride=1, cstride=1, cmap=cm.jet) ax.set_xlabel('X') ax.set_ylabel('Y') ax.set_zlabel('Z') fig.savefig('sp32.png')`

Ottengo un warning: UserWarning:

Matplotlib is building the font cache using fc-list. This may take a moment.

‘Matplotlib is building the font cache using fc-list.’

e alla fine ecco

**Cython Bindings per funzioni** `special`

Scipy also offers Cython bindings for scalar, typed versions of many of the functions in special. The following Cython code gives a simple example of how to use these functions:

Non ci sono riuscito. Se del caso sarĂ da approfondire ma la documentazione non mi sembra tanto chiara.

E cosĂŹ per tutto quanto riguarda Cython. ChissĂ se… Ă solo un problema di configurazione, pasticci dovuti ad Anaconda, se serve si puĂ˛ fare (*cit.*) đŻ