eckity.genetic_encodings.gp.tree.utils

 1"""
 2This module implements some utility functions. 
 3"""
 4
 5
 6def create_terminal_set(X):
 7    """
 8    Create a terminal set from a 2D-shaped numpy array. 
 9
10    Example: \n
11        X = array([[  4,   7,  -7, -10],  \n
12                   [  7,  -3,   3,  -8],  \n
13                   [  8,  -5,  -3,  -1]])
14
15    Returns the list: \n
16        ['x0', 'x1', 'x2', 'x3']
17
18    Parameters
19    ----------
20    X : 2d numpy array
21        The array from which we wish to extract features -- which will become terminals.
22
23    Returns
24    -------
25    Terminal set (a list).
26
27    """
28    
29    return [f'x{i}' for i in range(X.shape[1])]
30
31
32def _generate_args(X):
33    """
34    Generate keyword arguments from a 2d array for passing to GPTree.execute.
35    
36    Example: \n 
37        X = array([[  4,   7,  -7, -10],  \n
38                   [  7,  -3,   3,  -8],  \n
39                   [  8,  -5,  -3,  -1]])
40
41    Returns the dict: \n
42        {'x0': array([4, 7, 8]), \n
43         'x1': array([ 7, -3, -5]), \n
44         'x2': array([-7,  3, -3]), \n
45         'x3': array([-10,  -8,  -1])}     
46
47    Returns
48    -------
49    kwargs : dict
50        A keyword dictionary that includes a value for every variable x_i in the terminal set. 
51
52    """
53    
54    kwargs = dict()
55    for i in range(X.shape[1]):
56        kwargs[f'x{i}'] = X[:, i]
57    return kwargs