Source Code for Module target_functions.potential

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 2  #                                                                             # 
 3  # Copyright (C) 2009 Edward d'Auvergne                                        # 
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 5  # This file is part of the program relax (http://www.nmr-relax.com).          # 
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21   
22  # Module docstring. 
23  """Functions for calculating various optimisation potentials.""" 
24   
25   
26 -def quad_pot(values, pot, lower, upper): 
27      """Calculate the flat-bottom quadratic energy potential. 
28   
29      The formula used is:: 
30   
31                              / (x - x+)^2    if x > x+, 
32                              |                          
33          V_pQuad(x;x+,x-) = <  (x - x-)^2    if x < x-, 
34                              |                          
35                              \ 0             otherwise. 
36   
37      Where x+ and x- are the absolute bounds. 
38   
39   
40      @param values:  An array of values of x. 
41      @type values:   numpy float array 
42      @param pot:     The array to place the potential values (V_pQuad) into.  This should have the 
43                      same dimensions as the values array. 
44      @type pot:      numpy float array 
45      @param lower:   The array of lower bounds.  This should have the same dimensions as the values 
46                      array. 
47      @type lower:    numpy float array 
48      @param upper:   The array of upper bounds.  This should have the same dimensions as the values 
49                      array. 
50      @type upper:    numpy float array 
51      """ 
52   
53      # Loop over the x values. 
54      for i in range(len(values)): 
55          # First condition. 
56          if values[i] > upper[i]: 
57              pot[i] = (values[i] - upper[i])**2 
58   
59          # Second contition. 
60          elif values[i] < lower[i]: 
61              pot[i] = (values[i] - lower[i])**2 
62   
63          # Otherwise clear the array element. 
64          else: 
65              pot[i] = 0.0 
66