python.trfUtils.Fit Class Reference

Low-level fitting class. More...

Collaboration diagram for python.trfUtils.Fit:

Public Member Functions
	__init__ (self, **kwargs)
	fit (self)
	value (self, t)
	set_chi2 (self)
	chi2 (self)
	set_slope (self)
	slope (self)
	set_intersect (self)
	intersect (self)

Protected Attributes
	_math = math()

Static Protected Attributes
str	_model = 'linear'
	_x = None
	_y = None
	_xm = None
	_ym = None
	_ss = None
	_ss2 = None
	_slope = None
	_intersect = None
	_chi2 = None

Detailed Description

Low-level fitting class.

Definition at line 1386 of file trfUtils.py.

Constructor & Destructor Documentation

__init__()

python.trfUtils.Fit.__init__	(		self,
		**	kwargs )

Definition at line 1398 of file trfUtils.py.

    def __init__(self, **kwargs):
        # extract parameters
        self._model = kwargs.get('model', 'linear')
        self._x = kwargs.get('x', None)
        self._y = kwargs.get('y', None)
        self._math = math()
 
        if not self._x or not self._y:
            msg.warning('input data not defined')
 
        if len(self._x) != len(self._y):
            msg.warning('input data (lists) have different lengths')
 
        # base calculations
        if self._model == 'linear':
            self._ss = self._math.sum_square_dev(self._x)
            self._ss2 = self._math.sum_dev(self._x, self._y)
            self.set_slope()
            self._xm = self._math.mean(self._x)
            self._ym = self._math.mean(self._y)
            self.set_intersect()
            self.set_chi2()
 
        else:
            msg.warning("\'{0}\' model is not implemented".format(self._model))
 

Member Function Documentation

chi2()

python.trfUtils.Fit.chi2

(

self

)

Definition at line 1443 of file trfUtils.py.

    def chi2(self):
        #Return the chi2 value.
        return self._chi2
 

fit()

python.trfUtils.Fit.fit

(

self

)

Definition at line 1424 of file trfUtils.py.

    def fit(self):
        #Return fitting object.
        return self
 

intersect()

python.trfUtils.Fit.intersect

(

self

)

Definition at line 1465 of file trfUtils.py.

    def intersect(self):
        #Return the intersect value.
        return self._intersect
 
 

set_chi2()

python.trfUtils.Fit.set_chi2

(

self

)

Definition at line 1432 of file trfUtils.py.

    def set_chi2(self):
        #Calculate and set the chi2 value.
        y_observed = self._y
        y_expected = []
        for x in self._x:
            y_expected.append(self.value(x))
        if y_observed and y_observed != [] and y_expected and y_expected != []:
            self._chi2 = self._math.chi2(y_observed, y_expected)
        else:
            self._chi2 = None
 

set_intersect()

python.trfUtils.Fit.set_intersect

(

self

)

Definition at line 1458 of file trfUtils.py.

    def set_intersect(self):
        #Calculate and set the intersect of the linear fit.
        if self._ym and self._slope and self._xm:
            self._intersect = self._ym - self._slope * self._xm
        else:
            self._intersect = None
 

set_slope()

python.trfUtils.Fit.set_slope

(

self

)

Definition at line 1447 of file trfUtils.py.

    def set_slope(self):
        #Calculate and set the slope of the linear fit.
        if self._ss2 and self._ss and self._ss != 0:
            self._slope = self._ss2 / self._ss
        else:
            self._slope = None
 

slope()

python.trfUtils.Fit.slope

(

self

)

Definition at line 1454 of file trfUtils.py.

    def slope(self):
        #Return the slope value.
        return self._slope
 

value()

python.trfUtils.Fit.value	(		self,
			t )

Definition at line 1428 of file trfUtils.py.

    def value(self, t):
        #Return the value y(x=t) of a linear fit y(x) = slope * x + intersect.
        return self._slope * t + self._intersect
 

Member Data Documentation

_chi2

python.trfUtils.Fit._chi2 = None

staticprotected

Definition at line 1396 of file trfUtils.py.

_intersect

python.trfUtils.Fit._intersect = None

staticprotected

Definition at line 1395 of file trfUtils.py.

_math

python.trfUtils.Fit._math = math()

protected

Definition at line 1403 of file trfUtils.py.

_model

python.trfUtils.Fit._model = 'linear'

staticprotected

Definition at line 1387 of file trfUtils.py.

_slope

python.trfUtils.Fit._slope = None

staticprotected

Definition at line 1394 of file trfUtils.py.

_ss

python.trfUtils.Fit._ss = None

staticprotected

Definition at line 1392 of file trfUtils.py.

_ss2

python.trfUtils.Fit._ss2 = None

staticprotected

Definition at line 1393 of file trfUtils.py.

_x

python.trfUtils.Fit._x = None

staticprotected

Definition at line 1388 of file trfUtils.py.

_xm

python.trfUtils.Fit._xm = None

staticprotected

Definition at line 1390 of file trfUtils.py.

_y

python.trfUtils.Fit._y = None

staticprotected

Definition at line 1389 of file trfUtils.py.

_ym

python.trfUtils.Fit._ym = None

staticprotected

Definition at line 1391 of file trfUtils.py.

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The documentation for this class was generated from the following file:

• trfUtils.py