eppy_failed_test

test_tilt.py

import numpy as np
from math import acos as arccos
from math import sqrt as sqrt
from tinynumpy import array as array
from pytest_helpers import almostequal
import math

def angle2vecs(vec1,vec2):
    # vector a * vector b = |a|*|b|* cos(angle between vector a and vector b)
    dot = np.dot(vec1,vec2)
    vec1_modulus = sqrt((vec1*vec1).sum())
    vec2_modulus = sqrt((vec2*vec2).sum())
    if (vec1_modulus * vec2_modulus) == 0:
        cos_angle = 1
    else: cos_angle = dot / (vec1_modulus * vec2_modulus)
    return math.degrees(arccos(cos_angle))

#unit normal vector of plane defined by points a, b, and c
def unit_normal(a, b, c):
    x = np.linalg.det([[1,a[1],a[2]],[1,b[1],b[2]],[1,c[1],c[2]]])
    y = np.linalg.det([[a[0],1,a[2]],[b[0],1,b[2]],[c[0],1,c[2]]])
    z = np.linalg.det([[a[0],a[1],1],[b[0],b[1],1],[c[0],c[1],1]])
    magnitude = (x**2 + y**2 + z**2)**.5
    mag = (x/magnitude, y/magnitude, z/magnitude)
    if magnitude < 0.00000001: mag = (0,0,0)
    return mag
## end of http://code.activestate.com/recipes/578276/ }}}

def tilt(poly):
    """Tilt of a polygon poly"""
    N = len(poly) - 1
    vec = unit_normal(poly[0], poly[1], poly[N])
    vec_alt = array([vec[0], vec[1], vec[2]])
    vec_z = array([0,0,1])
    # return (90 - angle2vecs(vec_alt, vec_z)) # update by Santosh
    return (angle2vecs(vec_alt, vec_z))

def test_tilt():
    """test the tilt of a polygon poly"""
    data = (([(0,0,0), (1,0,0), (1,1,0), (0,1,0)],0),# polygon, answer,
            #([(0,0,0), (5,0,0), (5,0,8), (0,0,8)],90),
            #([(0,0,0), (1,0,0), (1,1,1), (0,1,1)],45),
            #([(3.571913,-9.390334,1.487381), (10.905826,-6.194443,1.487381),
             #(8.998819,-1.818255,0.0), (1.664906, -5.014146, 0.0)],90-72.693912),
            )
    for poly,answer in data:
        result = tilt(poly)
        assert almostequal(answer, result, places=3) == True

test_tilt()