def test_create_line_from_start_and_end_vertical_line(self):
start_x = 1
start_y = 5
end_x = 1
end_y = 25
model = LineModel.create_line_from_2points(start_x, start_y, end_x,
end_y)
expected_B = 0
expected_x_intercept = start_x
self.assertAlmostEqual(model.B, 0)
self.assertAlmostEqual(model.C / model.A, -expected_x_intercept)
def test_create_line_from_start_and_end_horizontal_line(self):
start_x = 0
start_y = 1
end_x = 1
end_y = 2
model = LineModel.create_line_from_2points(start_x, start_y, end_x,
end_y)
#equation ax+by+c=0
#slope=-a/b
#yinter=-c/b
expected_slope = 1
expected_y_intercept = 1
self.assertAlmostEqual(model.A / model.B, -expected_slope)
self.assertAlmostEqual(model.C / model.B, -expected_y_intercept)
def test_generate_points_at_regular_intervals_stline(self):
start_x = 0
start_y = 1
end_x = 10
end_y = 11
model = LineModel.create_line_from_2points(start_x, start_y, end_x,
end_y)
slope = -model.A / model.B
yintercept = -model.C / model.B
gap = 5
new_points = LineModel.generate_points_at_regular_intervals_stline(
start_x, start_y, end_x, end_y, gap)
count_of_new_points = len(new_points)
self.assertTrue(count_of_new_points > 0)
self.assertTrue(count_of_new_points < 4)
for new_point in new_points:
new_x = new_point.X
new_y = new_point.Y
expected_y = slope * new_x + yintercept
self.assertAlmostEqual(new_y, expected_y)