source: sasview/sansmodels/src/sans/models/BaseComponent.py @ 07b5556d

#!/usr/bin/env python

""" 
Provide base functionality for all model components
"""

# imports   
import copy
import numpy
#TO DO: that about a way to make the parameter
#is self return if it is fittable or not  

class BaseComponent:
    """ 
    Basic model component
    
    Since version 0.5.0, basic operations are no longer supported.
    """

    def __init__(self):
        """ Initialization"""
        
        ## Name of the model
        self.name = "BaseComponent"
        
        ## Parameters to be accessed by client
        self.params = {}
        self.details = {}
        ## Dictionary used to store the dispersity/averaging
        #  parameters of dispersed/averaged parameters.
        self.dispersion = {}
        # string containing information about the model such as the equation
        #of the given model, exception or possible use
        self.description=''
        #list of parameter that can be fitted
        self.fixed = []
        #list of non-fittable parameter
        self.non_fittable = []
        ## parameters with orientation
        self.orientation_params = []
        ## store dispersity reference
        self._persistency_dict = {}
        ## independent parameter name and unit [string]
        self.input_name = "Q"
        self.input_unit = "A^{-1}"
        ## output name and unit  [string]
        self.output_name = "Intensity"
        self.output_unit = "cm^{-1}"
        
    def __str__(self):
        """ 
        :return: string representatio

        """
        return self.name
   
    def is_fittable(self, par_name):
        """
        Check if a given parameter is fittable or not
        
        :param par_name: the parameter name to check 
        
        """
        return par_name.lower() in self.fixed
        #For the future
        #return self.params[str(par_name)].is_fittable()
   
    def run(self, x): return NotImplemented
    def runXY(self, x): return NotImplemented  
    def calculate_ER(self): return NotImplemented  
    def evalDistribution(self, qdist):
        """
        Evaluate a distribution of q-values.
        
        * For 1D, a numpy array is expected as input:
        
            evalDistribution(q)
            
        where q is a numpy array.
        
        
        * For 2D, a list of numpy arrays are expected: [qx_prime,qy_prime],
          where 1D arrays,
        
        qx_prime = [ qx[0], qx[1], qx[2], ....]
        and
        qy_prime = [ qy[0], qy[1], qy[2], ....] 
        
        Then get
        q = numpy.sqrt(qx_prime^2+qy_prime^2)
        
        that is a qr in 1D array;
        q = [q[0], q[1], q[2], ....] 
        
        :Note: Due to 2D speed issue, no anisotropic scattering 
            is supported for python models, thus C-models should have
             their own evalDistribution methods.
        
        The method is then called the following way:
        
        evalDistribution(q)
        where q is a numpy array.
        
        :param qdist: ndarray of scalar q-values or list [qx,qy] 
                    where qx,qy are 1D ndarrays 
        
        """
        if qdist.__class__.__name__ == 'list':
            # Check whether we have a list of ndarrays [qx,qy]
            if len(qdist)!=2 or \
                qdist[0].__class__.__name__ != 'ndarray' or \
                qdist[1].__class__.__name__ != 'ndarray':
                    raise RuntimeError, "evalDistribution expects a list of 2 ndarrays"
                
            # Extract qx and qy for code clarity
            qx = qdist[0]
            qy = qdist[1]
            
            # calculate q_r component for 2D isotropic
            q = numpy.sqrt(qx**2+qy**2)
            # vectorize the model function runXY
            v_model = numpy.vectorize(self.runXY,otypes=[float])
            # calculate the scattering
            iq_array = v_model(q)

            return iq_array
                
        elif qdist.__class__.__name__ == 'ndarray':
                # We have a simple 1D distribution of q-values
                v_model = numpy.vectorize(self.runXY,otypes=[float])
                iq_array = v_model(qdist)

                return iq_array
            
        else:
            mesg = "evalDistribution is expecting an ndarray of scalar q-values"
            mesg += " or a list [qx,qy] where qx,qy are 2D ndarrays."
            raise RuntimeError, mesg
        
    
    
    def clone(self):
        """ Returns a new object identical to the current object """
        obj = copy.deepcopy(self)
        return self._clone(obj)
    
    def _clone(self, obj):
        """
        Internal utility function to copy the internal
        data members to a fresh copy.
        """
        obj.params     = copy.deepcopy(self.params)
        obj.details    = copy.deepcopy(self.details)
        obj.dispersion = copy.deepcopy(self.dispersion)
        obj._persistency_dict = copy.deepcopy( self._persistency_dict)
        return obj

    def setParam(self, name, value):
        """ 
        Set the value of a model parameter
    
        :param name: name of the parameter
        :param value: value of the parameter
        
        """
        # Look for dispersion parameters
        toks = name.split('.')
        if len(toks)==2:
            for item in self.dispersion.keys():
                if item.lower()==toks[0].lower():
                    for par in self.dispersion[item]:
                        if par.lower() == toks[1].lower():
                            self.dispersion[item][par] = value
                            return
        else:
            # Look for standard parameter
            for item in self.params.keys():
                if item.lower()==name.lower():
                    self.params[item] = value
                    return
            
        raise ValueError, "Model does not contain parameter %s" % name
        
    def getParam(self, name):
        """ 
        Set the value of a model parameter

        :param name: name of the parameter
        
        """
        # Look for dispersion parameters
        toks = name.split('.')
        if len(toks)==2:
            for item in self.dispersion.keys():
                if item.lower()==toks[0].lower():
                    for par in self.dispersion[item]:
                        if par.lower() == toks[1].lower():
                            return self.dispersion[item][par]
        else:
            # Look for standard parameter
            for item in self.params.keys():
                if item.lower()==name.lower():
                    return self.params[item]
            
        raise ValueError, "Model does not contain parameter %s" % name
     
    def getParamList(self):
        """ 
        Return a list of all available parameters for the model
        """ 
        list = self.params.keys()
        # WARNING: Extending the list with the dispersion parameters
        list.extend(self.getDispParamList())
        return list
    
    def getDispParamList(self):
        """ 
        Return a list of all available parameters for the model
        """ 
        list = []
        
        for item in self.dispersion.keys():
            for p in self.dispersion[item].keys():
                if p not in ['type']:
                    list.append('%s.%s' % (item.lower(), p.lower()))
                    
        return list
    
    # Old-style methods that are no longer used
    def setParamWithToken(self, name, value, token, member): return NotImplemented
    def getParamWithToken(self, name, token, member): return NotImplemented
    def getParamListWithToken(self, token, member): return NotImplemented
    def __add__(self, other): raise ValueError, "Model operation are no longer supported"
    def __sub__(self, other): raise ValueError, "Model operation are no longer supported"
    def __mul__(self, other): raise ValueError, "Model operation are no longer supported"
    def __div__(self, other): raise ValueError, "Model operation are no longer supported"