#!/usr/bin/env python


import unittest
from numpy import zeros, array, allclose
from math import sqrt, pi
from anuga.pyvolution.config import epsilon

from numerical_tools import *

def test_function(x, y):
    return x+y

class Test_Numerical_Tools(unittest.TestCase):
    def setUp(self):
        pass

    def tearDown(self):
        pass


    def test_angle(self):
        assert allclose(angle([1.0, 1.0])/pi*180, 45.0)


    def test_anglediff(self):
        assert allclose(anglediff([0.0, 1.], [1.0, 1.0])/pi*180, 45.0)



	
    def test_ensure_numeric(self):
        from numerical_tools import ensure_numeric
        from numpy import ArrayType, Float, array

        A = [1,2,3,4]
        B = ensure_numeric(A)
        assert type(B) == ArrayType
        assert B.dtype.char == 'l'
        assert B[0] == 1 and B[1] == 2 and B[2] == 3 and B[3] == 4


        A = [1,2,3.14,4]
        B = ensure_numeric(A)
        assert type(B) == ArrayType
        assert B.dtype.char == 'd'
        assert B[0] == 1 and B[1] == 2 and B[2] == 3.14 and B[3] == 4


        A = [1,2,3,4]
        B = ensure_numeric(A, Float)
        assert type(B) == ArrayType
        assert B.dtype.char == 'd'
        assert B[0] == 1.0 and B[1] == 2.0 and B[2] == 3.0 and B[3] == 4.0


        A = [1,2,3,4]
        B = ensure_numeric(A, Float)
        assert type(B) == ArrayType
        assert B.dtype.char == 'd'
        assert B[0] == 1.0 and B[1] == 2.0 and B[2] == 3.0 and B[3] == 4.0


        A = array([1,2,3,4])
        B = ensure_numeric(A)
        assert type(B) == ArrayType
        assert B.dtype.char == 'l'
        assert (A == B).all()    
        assert A is B   #Same object


        A = array([1,2,3,4])
        B = ensure_numeric(A, Float)
        assert type(B) == ArrayType
        assert B.dtype.char == 'd'        
        assert (A == B).all()            
        assert A is not B   #Not the same object


    def test_gradient(self):
        x0 = 0.0; y0 = 0.0; z0 = 0.0
        x1 = 1.0; y1 = 0.0; z1 = -1.0
        x2 = 0.0; y2 = 1.0; z2 = 0.0

        zx, zy = gradient(x0, y0, x1, y1, x2, y2, z0, z1, z2)

        assert zx == -1.0
        assert zy == 0.0

    def test_gradient_more(self):
        x0 = 2.0/3; y0 = 2.0/3
        x1=  8.0/3; y1 = 2.0/3
        x2 = 2.0/3; y2 = 8.0/3

        q0 = 2.0+2.0/3
        q1 = 8.0+2.0/3
        q2 = 2.0+8.0/3

        #Gradient of fitted pwl surface
        a, b = gradient(x0, y0, x1, y1, x2, y2, q0, q1, q2)

        assert abs(a - 3.0) < epsilon
        assert abs(b - 1.0) < epsilon


    def test_gradient2(self):
        """Test two-point gradient
        """
        
        x0 = 5.0; y0 = 5.0; z0 = 10.0
        x1 = 8.0; y1 = 2.0; z1 = 1.0
        x2 = 8.0; y2 = 8.0; z2 = 10.0

        #Reference
        zx, zy = gradient(x0, y0, x1, y1, x2, y2, z0, z1, z2)
        a, b = gradient2(x0, y0, x1, y1, z0, z1)

        assert zx == a
        assert zy == b

        z2_computed = z0 + a*(x2-x0) + b*(y2-y0)
        assert z2_computed == z2
        
    def test_gradient2_more(self):
        """Test two-point gradient more
        """
        x0 = 2.0; y0 = 2.0
        x1 = 8.0; y1 = 3.0
        x2 = 1.0; y2 = 8.0

        q0 = 2.0
        q1 = 8.0
        q2 = q0

        #Gradient of fitted pwl surface
        a_ref, b_ref = gradient(x0, y0, x1, y1, x2, y2, q0, q1, q2)
        a, b = gradient2(x0, y0, x1, y1, q0, q1)        

        assert a == a_ref
        assert b == b_ref


    def test_histogram(self):
        """Test histogram with different bin boundaries
        """
        
        a = [1,1,1,1,1,2,1,3,2,3,1,2,3,4,1]


        #There are four elements greater than or equal to 3
        bins = [3]
        assert allclose(histogram(a, bins), [4])


        bins = [ min(a) ]
        assert allclose(histogram(a, bins), [len(a)])


        bins = [ max(a)+0.00001 ]
        assert allclose(histogram(a, bins), [0])        

        
        bins = [1,2,3,4]
        assert allclose(histogram(a, bins), [8,3,3,1])


        bins = [0.5,1.5,2,3]
        assert allclose(histogram(a, bins), [8,0,3,4])


        

    def test_that_C_extension_compiles(self):
        FN = 'util_ext.c'
        try:
            import util_ext
        except:
            from compile import compile

            try:
                compile(FN)
            except:
                raise 'Could not compile %s' %FN
            else:
                import util_ext


    def test_gradient_C_extension(self):
        from util_ext import gradient as gradient_c

        x0 = 2.0/3; y0 = 2.0/3
        x1=  8.0/3; y1 = 2.0/3
        x2 = 2.0/3; y2 = 8.0/3

        q0 = 2.0+2.0/3
        q1 = 8.0+2.0/3
        q2 = 2.0+8.0/3

        #Gradient of fitted pwl surface
        a, b = gradient_c(x0, y0, x1, y1, x2, y2, q0, q1, q2)

        assert abs(a - 3.0) < epsilon
        assert abs(b - 1.0) < epsilon


    def test_gradient_C_extension3(self):
        from util_ext import gradient as gradient_c

        from numpy.random import uniform, seed
        seed((17,53))

        x0, x1, x2, y0, y1, y2 = uniform(0.0,3.0,6)

        q0 = uniform(0.0, 10.0, 4)
        q1 = uniform(1.0, 3.0, 4)
        q2 = uniform(7.0, 20.0, 4)


        for i in range(4):
            #Gradient of fitted pwl surface
            a_ref, b_ref = gradient_python(x0, y0, x1, y1, x2, y2,
                                           q0[i], q1[i], q2[i])

            #print a_ref, b_ref
            a, b = gradient_c(x0, y0, x1, y1, x2, y2,
                              q0[i], q1[i], q2[i])

            #print a, a_ref, b, b_ref
            assert abs(a - a_ref) < epsilon
            assert abs(b - b_ref) < epsilon

        


#-------------------------------------------------------------
if __name__ == "__main__":
    suite = unittest.makeSuite(Test_Numerical_Tools,'test')
    runner = unittest.TextTestRunner()
    runner.run(suite)