Package lib :: Package dispersion :: Module mmq_cr72
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Module mmq_cr72

source code

The CR72 model extended for MMQ CPMG data, called the MMQ CR72 model.

Description

This module is for the function, gradient and Hessian of the MMQ CR72 model.

References

The Carver and Richards (1972) 2-site model for all times scales was extended for multiple-MQ (MMQ) CPMG data by:

Links

More information on the MMQ CR72 model can be found in the:

Functions [hide private]
 
r2eff_mmq_cr72(r20=None, pA=None, pB=None, dw=None, dwH=None, kex=None, k_AB=None, k_BA=None, cpmg_frqs=None, inv_tcpmg=None, tcp=None, back_calc=None, num_points=None, power=None)
The CR72 model extended to MMQ CPMG data.
source code
Variables [hide private]
  __package__ = 'lib.dispersion'

Imports: arccosh, cos, cosh, log, sin, sqrt


Function Details [hide private]

r2eff_mmq_cr72(r20=None, pA=None, pB=None, dw=None, dwH=None, kex=None, k_AB=None, k_BA=None, cpmg_frqs=None, inv_tcpmg=None, tcp=None, back_calc=None, num_points=None, power=None)

source code 

The CR72 model extended to MMQ CPMG data.

This function calculates and stores the R2eff values.

Parameters:
  • r20 (float) - The R2 value in the absence of exchange.
  • pA (float) - The population of state A.
  • pB (float) - The population of state B.
  • dw (float) - The chemical exchange difference between states A and B in rad/s.
  • dwH (float) - The proton chemical exchange difference between states A and B in rad/s.
  • kex (float) - The kex parameter value (the exchange rate in rad/s).
  • k_AB (float) - The rate of exchange from site A to B (rad/s).
  • k_BA (float) - The rate of exchange from site B to A (rad/s).
  • cpmg_frqs (numpy rank-1 float array) - The CPMG nu1 frequencies.
  • inv_tcpmg (float) - The inverse of the total duration of the CPMG element (in inverse seconds).
  • tcp (numpy rank-1 float array) - The tau_CPMG times (1 / 4.nu1).
  • back_calc (numpy rank-1 float array) - The array for holding the back calculated R2eff values. Each element corresponds to one of the CPMG nu1 frequencies.
  • num_points (int) - The number of points on the dispersion curve, equal to the length of the tcp and back_calc arguments.
  • power (numpy int16, rank-1 array) - The matrix exponential power array.