Source Code for Module generic_fns.nuclei

  1  ############################################################################### 
  2  #                                                                             # 
  3  # Copyright (C) 2003, 2004 Edward d'Auvergne                                  # 
  4  #                                                                             # 
  5  # This file is part of the program relax.                                     # 
  6  #                                                                             # 
  7  # relax is free software; you can redistribute it and/or modify               # 
  8  # it under the terms of the GNU General Public License as published by        # 
  9  # the Free Software Foundation; either version 2 of the License, or           # 
 10  # (at your option) any later version.                                         # 
 11  #                                                                             # 
 12  # relax is distributed in the hope that it will be useful,                    # 
 13  # but WITHOUT ANY WARRANTY; without even the implied warranty of              # 
 14  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               # 
 15  # GNU General Public License for more details.                                # 
 16  #                                                                             # 
 17  # You should have received a copy of the GNU General Public License           # 
 18  # along with relax; if not, write to the Free Software                        # 
 19  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA   # 
 20  #                                                                             # 
 21  ############################################################################### 
 22   
 23  from re import match 
 24   
 25   
 26 -class Nuclei: 
 27 -    def __init__(self, relax): 
 28          """Class containing the function to set the gyromagnetic ratio of the heteronucleus.""" 
 29   
 30          self.relax = relax 
 31   
 32   
 33 -    def find_nucleus(self): 
 34          """Function for finding the nucleus corresponding to 'self.relax.data.gx'.""" 
 35   
 36          # Not set. 
 37          if not hasattr(self.relax.data, 'gx'): 
 38              return 
 39   
 40          # Nitrogen. 
 41          if self.relax.data.gx == self.gn(): 
 42              return 'N' 
 43   
 44          # Carbon 
 45          if self.relax.data.gx == self.gc(): 
 46              return 'C' 
 47   
 48          # Oxygen. 
 49          if self.relax.data.gx == self.go(): 
 50              return 'O' 
 51   
 52          # Phosphate. 
 53          if self.relax.data.gx == self.gp(): 
 54              return 'P' 
 55   
 56   
 57 -    def gc(self): 
 58          """The 13C gyromagnetic ratio.""" 
 59   
 60          return 6.728e7 
 61   
 62   
 63 -    def gh(self): 
 64          """The 1H gyromagnetic ratio.""" 
 65   
 66          # Old, low precision gyromagnetic ratio. 
 67          #return 26.7522e7 
 68   
 69          return 26.7522212e7 
 70   
 71   
 72 -    def gn(self): 
 73          """The 15N gyromagnetic ratio.""" 
 74   
 75          return -2.7126e7 
 76   
 77   
 78 -    def go(self): 
 79          """The 17O gyromagnetic ratio.""" 
 80   
 81          return -3.628e7 
 82   
 83   
 84 -    def gp(self): 
 85          """The 31P gyromagnetic ratio.""" 
 86   
 87          return 1.0841e8 
 88   
 89   
 90 -    def set_values(self, heteronuc): 
 91          """Function for setting the gyromagnetic ratio of the heteronucleus.""" 
 92   
 93          # Nitrogen. 
 94          if match('[Nn]', heteronuc): 
 95              self.relax.data.gx = self.gn() 
 96   
 97          # Carbon 
 98          elif match('[Cc]', heteronuc): 
 99              self.relax.data.gx = self.gc() 
100   
101          # Oxygen. 
102          elif match('[Oo]', heteronuc): 
103              self.relax.data.gx = self.go() 
104   
105          # Phosphate. 
106          elif match('[Pp]', heteronuc): 
107              self.relax.data.gx = self.gp() 
108   
109          # Incorrect arguement. 
110          else: 
111              raise RelaxInvalidError, ('heteronucleus', heteronuc) 
112   
113          # Set the proton gyromagnetic ratio. 
114          self.relax.data.gh = self.gh() 
115   
116          # Calculate the ratio of the gyromagnetic ratios. 
117          self.relax.data.g_ratio = self.relax.data.gh / self.relax.data.gx 
118