Package lib :: Package frame_order :: Module iso_cone_torsionless
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Source Code for Module lib.frame_order.iso_cone_torsionless

  1  ############################################################################### 
  2  #                                                                             # 
  3  # Copyright (C) 2009-2014 Edward d'Auvergne                                   # 
  4  #                                                                             # 
  5  # This file is part of the program relax (http://www.nmr-relax.com).          # 
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 21   
 22  # Module docstring. 
 23  """Module for the handling of Frame Order.""" 
 24   
 25  # Python module imports. 
 26  from math import cos, pi, sqrt 
 27  try: 
 28      from scipy.integrate import dblquad 
 29  except ImportError: 
 30      pass 
 31   
 32  # relax module imports. 
 33  from lib.frame_order.matrix_ops import pcs_pivot_motion_torsionless, pcs_pivot_motion_torsionless_qrint, rotate_daeg 
 34   
 35   
36 -def compile_2nd_matrix_iso_cone_torsionless(matrix, Rx2_eigen, cone_theta):
37 """Generate the rotated 2nd degree Frame Order matrix for the torsionless isotropic cone. 38 39 The cone axis is assumed to be parallel to the z-axis in the eigenframe. 40 41 42 @param matrix: The Frame Order matrix, 2nd degree to be populated. 43 @type matrix: numpy 9D, rank-2 array 44 @param Rx2_eigen: The Kronecker product of the eigenframe rotation matrix with itself. 45 @type Rx2_eigen: numpy 9D, rank-2 array 46 @param cone_theta: The cone opening angle. 47 @type cone_theta: float 48 """ 49 50 # Zeros. 51 for i in range(9): 52 for j in range(9): 53 matrix[i, j] = 0.0 54 55 # Repetitive trig calculations. 56 cos_tmax = cos(cone_theta) 57 cos_tmax2 = cos_tmax**2 58 59 # Diagonal. 60 matrix[0, 0] = (3.0*cos_tmax2 + 6.0*cos_tmax + 15.0) / 24.0 61 matrix[1, 1] = (cos_tmax2 + 10.0*cos_tmax + 13.0) / 24.0 62 matrix[2, 2] = (4.0*cos_tmax2 + 10.0*cos_tmax + 10.0) / 24.0 63 matrix[3, 3] = matrix[1, 1] 64 matrix[4, 4] = matrix[0, 0] 65 matrix[5, 5] = matrix[2, 2] 66 matrix[6, 6] = matrix[2, 2] 67 matrix[7, 7] = matrix[2, 2] 68 matrix[8, 8] = (cos_tmax2 + cos_tmax + 1.0) / 3.0 69 70 # Off diagonal set 1. 71 matrix[0, 4] = matrix[4, 0] = (cos_tmax2 - 2.0*cos_tmax + 1.0) / 24.0 72 matrix[0, 8] = matrix[8, 0] = -(cos_tmax2 + cos_tmax - 2.0) / 6.0 73 matrix[4, 8] = matrix[8, 4] = matrix[0, 8] 74 75 # Off diagonal set 2. 76 matrix[1, 3] = matrix[3, 1] = matrix[0, 4] 77 matrix[2, 6] = matrix[6, 2] = -matrix[0, 8] 78 matrix[5, 7] = matrix[7, 5] = -matrix[0, 8] 79 80 # Rotate and return the frame order matrix. 81 return rotate_daeg(matrix, Rx2_eigen)
82 83
84 -def pcs_numeric_int_iso_cone_torsionless(theta_max=None, c=None, r_pivot_atom=None, r_ln_pivot=None, A=None, R_eigen=None, RT_eigen=None, Ri_prime=None):
85 """Determine the averaged PCS value via numerical integration. 86 87 @keyword theta_max: The half cone angle. 88 @type theta_max: float 89 @keyword c: The PCS constant (without the interatomic distance and in Angstrom units). 90 @type c: float 91 @keyword r_pivot_atom: The pivot point to atom vector. 92 @type r_pivot_atom: numpy rank-1, 3D array 93 @keyword r_ln_pivot: The lanthanide position to pivot point vector. 94 @type r_ln_pivot: numpy rank-1, 3D array 95 @keyword A: The full alignment tensor of the non-moving domain. 96 @type A: numpy rank-2, 3D array 97 @keyword R_eigen: The eigenframe rotation matrix. 98 @type R_eigen: numpy rank-2, 3D array 99 @keyword RT_eigen: The transpose of the eigenframe rotation matrix (for faster calculations). 100 @type RT_eigen: numpy rank-2, 3D array 101 @keyword Ri_prime: The empty rotation matrix for the in-frame isotropic cone motion, used to calculate the PCS for each state i in the numerical integration. 102 @type Ri_prime: numpy rank-2, 3D array 103 @return: The averaged PCS value. 104 @rtype: float 105 """ 106 107 # Perform numerical integration. 108 result = dblquad(pcs_pivot_motion_torsionless, -pi, pi, lambda phi: 0.0, lambda phi: theta_max, args=(r_pivot_atom, r_ln_pivot, A, R_eigen, RT_eigen, Ri_prime)) 109 110 # The surface area normalisation factor. 111 SA = 2.0 * pi * (1.0 - cos(theta_max)) 112 113 # Return the value. 114 return c * result[0] / SA
115 116
117 -def pcs_numeric_int_iso_cone_torsionless_qrint(points=None, theta_max=None, c=None, full_in_ref_frame=None, r_pivot_atom=None, r_pivot_atom_rev=None, r_ln_pivot=None, A=None, R_eigen=None, RT_eigen=None, Ri_prime=None, pcs_theta=None, pcs_theta_err=None, missing_pcs=None, error_flag=False):
118 """Determine the averaged PCS value via numerical integration. 119 120 @keyword points: The Sobol points in the torsion-tilt angle space. 121 @type points: numpy rank-2, 3D array 122 @keyword theta_max: The half cone angle. 123 @type theta_max: float 124 @keyword c: The PCS constant (without the interatomic distance and in Angstrom units). 125 @type c: numpy rank-1 array 126 @keyword full_in_ref_frame: An array of flags specifying if the tensor in the reference frame is the full or reduced tensor. 127 @type full_in_ref_frame: numpy rank-1 array 128 @keyword r_pivot_atom: The pivot point to atom vector. 129 @type r_pivot_atom: numpy rank-2, 3D array 130 @keyword r_pivot_atom_rev: The reversed pivot point to atom vector. 131 @type r_pivot_atom_rev: numpy rank-2, 3D array 132 @keyword r_ln_pivot: The lanthanide position to pivot point vector. 133 @type r_ln_pivot: numpy rank-2, 3D array 134 @keyword A: The full alignment tensor of the non-moving domain. 135 @type A: numpy rank-2, 3D array 136 @keyword R_eigen: The eigenframe rotation matrix. 137 @type R_eigen: numpy rank-2, 3D array 138 @keyword RT_eigen: The transpose of the eigenframe rotation matrix (for faster calculations). 139 @type RT_eigen: numpy rank-2, 3D array 140 @keyword Ri_prime: The empty rotation matrix for the in-frame isotropic cone motion, used to calculate the PCS for each state i in the numerical integration. 141 @type Ri_prime: numpy rank-2, 3D array 142 @keyword pcs_theta: The storage structure for the back-calculated PCS values. 143 @type pcs_theta: numpy rank-2 array 144 @keyword pcs_theta_err: The storage structure for the back-calculated PCS errors. 145 @type pcs_theta_err: numpy rank-2 array 146 @keyword missing_pcs: A structure used to indicate which PCS values are missing. 147 @type missing_pcs: numpy rank-2 array 148 @keyword error_flag: A flag which if True will cause the PCS errors to be estimated and stored in pcs_theta_err. 149 @type error_flag: bool 150 """ 151 152 # Clear the data structures. 153 for i in range(len(pcs_theta)): 154 for j in range(len(pcs_theta[i])): 155 pcs_theta[i, j] = 0.0 156 pcs_theta_err[i, j] = 0.0 157 158 # Loop over the samples. 159 num = 0 160 for i in range(len(points)): 161 # Unpack the point. 162 theta, phi = points[i] 163 164 # Outside of the distribution, so skip the point. 165 if theta > theta_max: 166 continue 167 168 # Calculate the PCSs for this state. 169 pcs_pivot_motion_torsionless_qrint(theta_i=theta, phi_i=phi, full_in_ref_frame=full_in_ref_frame, r_pivot_atom=r_pivot_atom, r_pivot_atom_rev=r_pivot_atom_rev, r_ln_pivot=r_ln_pivot, A=A, R_eigen=R_eigen, RT_eigen=RT_eigen, Ri_prime=Ri_prime, pcs_theta=pcs_theta, pcs_theta_err=pcs_theta_err, missing_pcs=missing_pcs) 170 171 # Increment the number of points. 172 num += 1 173 174 # Calculate the PCS and error. 175 for i in range(len(pcs_theta)): 176 for j in range(len(pcs_theta[i])): 177 # The average PCS. 178 pcs_theta[i, j] = c[i] * pcs_theta[i, j] / float(num) 179 180 # The error. 181 if error_flag: 182 pcs_theta_err[i, j] = abs(pcs_theta_err[i, j] / float(num) - pcs_theta[i, j]**2) / float(num) 183 pcs_theta_err[i, j] = c[i] * sqrt(pcs_theta_err[i, j]) 184 print("%8.3f +/- %-8.3f" % (pcs_theta[i, j]*1e6, pcs_theta_err[i, j]*1e6))
185