source: sasview/src/sas/plottools/LineModel.py @ 225aca8

#!/usr/bin/env python
"""
Provide Line function (y= A + Bx)
"""

import math

class LineModel(object):
    """
    Class that evaluates a linear model.

    f(x) = A + Bx

    List of default parameters:
    A = 0.0
    B = 0.0
    """

    def __init__(self):
        """ Initialization """
        # # Name of the model
        self.name = "LineModel"

        # # Define parameters
        self.params = {}
        self.params['A'] = 1.0
        self.params['B'] = 1.0

        # # Parameter details [units, min, max]
        self.details = {}
        self.details['A'] = ['', None, None]
        self.details['B'] = ['', None, None]

    def getParam(self, name):
        """
            Return parameter value
        """
        return self.params[name.upper()]

    def setParam(self, name, value):
        """
            Set parameter value
        """
        self.params[name.upper()] = value

    def _line(self, x):
        """
        Evaluate the function

        :param x: x-value

        :return: function value

        """
        return  self.params['A'] + (x * self.params['B'])

    def run(self, x=0.0):
        """
        Evaluate the model

        :param x: simple value

        :return: (Line value)
        """
        if x.__class__.__name__ == 'list':
            return self._line(x[0] * math.cos(x[1])) * \
                                self._line(x[0] * math.sin(x[1]))
        elif x.__class__.__name__ == 'tuple':
            msg = "Tuples are not allowed as input to BaseComponent models"
            raise ValueError, msg
        else:
            return self._line(x)

    def runXY(self, x=0.0):
        """
        Evaluate the model

        :param x: simple value

        :return: Line value

        """
        if x.__class__.__name__ == 'list':
            return self._line(x[0]) * self._line(x[1])
        elif x.__class__.__name__ == 'tuple':
            msg = "Tuples are not allowed as input to BaseComponent models"
            raise ValueError, msg
        else:
            return self._line(x)