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

# ***************************************************************************
# *   Copyright (C) 2011-2012 by Andreas Kührmann [kuean@users.sf.net]      *
# *                                                                         *
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# *   This program is free software; you can redistribute it and/or modify  *
# *   the Free Software Foundation; either version 3 of the License, or     *
# *   (at your option) any later version.                                   *
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# *   This program is distributed in the hope that it will be useful,       *
# *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
# *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
# *   GNU General Public License for more details.                          *
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# *   You should have received a copy of the GNU General Public License     *
# *   along with this program; if not, write to the                         *
# *   Free Software Foundation, Inc.,                                       *
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# ***************************************************************************

import numpy as np

from d2pcamberline import D2PCamberLine

__all__ = ['D3PCamberLine']

[docs]class D3PCamberLine(D2PCamberLine):
"""
some documentation
"""

def __init__(self):
super(D3PCamberLine, self).__init__()
# properties (initialized by user)
self.__angle_of_outflow = fdn.Uninit('angle_of_outflow')
# add user properties to initialization summary
self._properties.append('angle_of_outflow')

@property
def angle_of_outflow(self):
r"""
Type: int or float - values between (exclusive) 0 and :math:\pi
only
"""
return self.__angle_of_outflow

@angle_of_outflow.setter
@fdn.restrict(new_angle_of_outflow=fdn.OpenInterval(0, np.pi))
[docs]    def angle_of_outflow(self, new_angle_of_outflow):
if self.__angle_of_outflow != new_angle_of_outflow:
self.__angle_of_outflow = new_angle_of_outflow
self.update()

def __get_coefficients(self):
self._check_initialization('angle_of_inflow', 'angle_of_outflow')
slop_inlet = np.tan(self.angle_of_inflow - np.pi / 2.)
slop_outlet = np.tan(np.pi / 2. - self.angle_of_outflow)
a_3 = slop_inlet - np.tan(slop_outlet)
a_2 = -slop_inlet - a_3
a_1 = slop_inlet
return a_1, a_2, a_3

@fdn.memoize
[docs]    def get_derivations(self):
"""
get_derivations()

Returns: ndarray

Calculates camber line derivations and returns them in an array.

.. note:: **Note**

The return value will be cached. Recalling this method returns the
cached value, if the attribues are unchanged.
"""
self._check_initialization()
self._cached = True
x = self.distribution(self.sample_rate)
a_1, a_2, a_3 = self.__get_coefficients()
return x * (x * 3 * a_3 + 2 * a_2) + a_1

@fdn.memoize
[docs]    def as_array(self):
"""
as_array()

Returns: ndarray

Calculates camber line coordinates and returns them in an array.

.. note:: **Note**

The return value will be cached. Recalling this method returns the
cached value, if the attribues are unchanged.
"""
self._check_initialization()
self._cached = True
x = self.distribution(self.sample_rate)
a_1, a_2, a_3 = self.__get_coefficients()
y = x * (x * (x * a_3 + a_2) + a_1)
return np.reshape(np.append(x, y), (-1, 2), "F")