Custom Error Measures

Custom error measures must inherit from pycast.errors.BaseErrorMeasure and implement the following functions:

• _calculate(self, startingPercentage, endPercentage)
• local_error(self, originalValue, calculatedValue)

Code to start with

To implement your custom error measrue, it is recommended to start with the following example:

#!/usr/bin/env python
# -*- coding: UTF-8 -*-

#Copyright (c) 2012-2015 Christian Schwarz
#
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#distribute, sublicense, and/or sell copies of the Software, and to
#permit persons to whom the Software is furnished to do so, subject to
#the following conditions:
#
#The above copyright notice and this permission notice shall be
#included in all copies or substantial portions of the Software.
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#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
#EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
#MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
#NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
#LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
#OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
#WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

from pycast.errors import BaseErrorMeasure

class CustomErrorMeasure(BaseErrorMeasure):
    """Implements your custom error measure.

    Please provide some explanation here!
    """

    def _calculate(self, startingPercentage, endPercentage):
        """This is the error calculation function that gets called by :py:meth:`BaseErrorMeasure.get_error`.

        Both parameters will be correct at this time.

        :param Float startingPercentage: Defines the start of the interval. This has to be a value in [0.0, 100.0].
            It represents the value, where the error calculation should be started.
            25.0 for example means that the first 25% of all calculated errors will be ignored.
        :param Float endPercentage:    Defines the end of the interval. This has to be a value in [0.0, 100.0].
            It represents the vlaue, after which all error values will be ignored. 90.0 for example means that
            the last 10% of all local errors will be ignored.

        :return:    Returns a float representing the error.
        :rtype:     Float

        :raise:    Raises a :py:exc:`NotImplementedError` if the child class does not overwrite this method.
        """
        ## get the defined subset of error values
        errorValues = self._get_error_values(startingPercentage, endPercentage)

        ## Implement the error calculation here!

    def local_error(self, originalValue, calculatedValue):
        """Calculates the error between the two given values.

        :param Numeric originalValue:    Value of the original data.
        :param Numeric calculatedValue:    Value of the calculated TimeSeries that
            corresponds to originalValue.

        :return:    Returns the error measure of the two given values.
        :rtype:     Numeric

        :raise:    Raises a :py:exc:`NotImplementedError` if the child class does not overwrite this method.
        """
        ## Implement the local error calculation here!