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

# ***************************************************************************
# *   Copyright (C) 2011-2013 by Andreas Kührmann [kuean@users.sf.net] and  *
# *   Fabian Schäffer                                                       *
# *                                                                         *
# *   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.                                   *
# *                                                                         *
# *   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.                          *
# *                                                                         *
# *   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.,                                       *
# *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
# ***************************************************************************

import numpy as np

__all__ = ['JoukowskiCamberLine']

[docs]class JoukowskiCamberLine(bcls.AnalyticalCamberLine):
"""
The Joukowski-Camberline is characterized by the maximum camber.
Its geometry results from the Joukowski-Transformation, the camberline
is defined for small bulges in the following form:
"""

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

@property
def max_camber(self):
return self.__max_camber

@max_camber.setter
@fdn.restrict(new_max_camber=(int, float))
def max_camber(self, new_max_camber):
"""
Type: int or float
"""
if self.__max_camber != new_max_camber:
self.__max_camber = new_max_camber
self.update()

@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)
return self.max_camber * (1 - 2 * x)

@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)
y = self.max_camber * x * (1 - x)
return np.reshape(np.append(x, y), (-1, 2), "F")