Source code for sas.models.GaussLorentzGelModel

""" 
    Provide I(q) = I_0 exp ( - R_g^2 q^2 / 3.0)
    GaussLorentzGel function as a BaseComponent model
"""
from sas.models.BaseComponent import BaseComponent
import math

[docs]class GaussLorentzGelModel(BaseComponent): """ Class that evaluates a GaussLorentzGel model. I(q) = scale_g*exp(- q^2*Z^2 / 2)+scale_l/(1+q^2*z^2) + background List of default parameters: scale_g = Gauss scale factor Z = Static correlation length scale_l = Lorentzian scale factor z = Dynamic correlation length background = Incoherent background """ def __init__(self): """ Initialization """ # Initialize BaseComponent first, then sphere BaseComponent.__init__(self) ## Name of the model self.name = "GaussLorentzGel" self.description = """I(q)=scale_g*exp(-q^2*Z^2/2)+scale_l/(1+q^2*z^2) + background List of default parameters: scale_g = Gauss scale factor stat_colength = Static correlation length scale_l = Lorentzian scale factor dyn_colength = Dynamic correlation length background = Incoherent background """ ## Define parameters self.params = {} self.params['scale_g'] = 100.0 self.params['stat_colength'] = 100.0 self.params['scale_l'] = 50.0 self.params['dyn_colength'] = 20.0 self.params['background'] = 0.0 ## Parameter details [units, min, max] self.details = {} self.details['scale_g'] = ['', None, None] self.details['stat_colength'] = ['A', None, None] self.details['scale_l'] = ['', None, None] self.details['dyn_colength'] = ['A', None, None] self.details['background'] = ['[1/cm]', None, None] #list of parameter that cannot be fitted self.fixed = [] def _gausslorentzgel(self, x): """ Model definition """ inten = self.params['scale_g'] \ *math.exp(-1.0*x*x*self.params['stat_colength']* \ self.params['stat_colength']/2.0) + self.params['scale_l']/ \ (1.0 + (x*self.params['dyn_colength'])* \ (x*self.params['dyn_colength'])) + self.params['background'] return inten
[docs] def run(self, x = 0.0): """ Evaluate the model @param x: input q-value (float or [float, float] as [r, theta]) @return: (guinier value) """ if x.__class__.__name__ == 'list': return self._gausslorentzgel(x[0]) elif x.__class__.__name__ == 'tuple': raise ValueError, "Tuples are not allowed as input to models" else: return self._gausslorentzgel(x)
[docs] def runXY(self, x = 0.0): """ Evaluate the model @param x: input q-value (float or [float, float] as [qx, qy]) @return: guinier value """ if x.__class__.__name__ == 'list': q = math.sqrt(x[0]**2 + x[1]**2) return self._gausslorentzgel(q) elif x.__class__.__name__ == 'tuple': raise ValueError, "Tuples are not allowed as input to models" else: return self._gausslorentzgel(x)