orb_slam3_details/Thirdparty/Sophus/py/sophus/so2.py

187 lines
5.7 KiB
Python

import sympy
import sys
import unittest
import sophus
import functools
class So2:
""" 2 dimensional group of orthogonal matrices with determinant 1 """
def __init__(self, z):
""" internally represented by a unit complex number z """
self.z = z
@staticmethod
def exp(theta):
""" exponential map """
return So2(
sophus.Complex(
sympy.cos(theta),
sympy.sin(theta)))
def log(self):
""" logarithmic map"""
return sympy.atan2(self.z.imag, self.z.real)
def __repr__(self):
return "So2:" + repr(self.z)
@staticmethod
def hat(theta):
return sympy.Matrix([[0, -theta],
[theta, 0]])
def matrix(self):
""" returns matrix representation """
return sympy.Matrix([
[self.z.real, -self.z.imag],
[self.z.imag, self.z.real]])
def __mul__(self, right):
""" left-multiplication
either rotation concatenation or point-transform """
if isinstance(right, sympy.Matrix):
assert right.shape == (2, 1), right.shape
return self.matrix() * right
elif isinstance(right, So2):
return So2(self.z * right.z)
assert False, "unsupported type: {0}".format(type(right))
def __getitem__(self, key):
return self.z[key]
@staticmethod
def calc_Dx_exp_x(x):
return sympy.Matrix(2, 1, lambda r, c:
sympy.diff(So2.exp(x)[r], x))
@staticmethod
def Dx_exp_x_at_0():
return sympy.Matrix([0, 1])
@staticmethod
def calc_Dx_exp_x_at_0(x):
return So2.calc_Dx_exp_x(x).limit(x, 0)
def calc_Dx_this_mul_exp_x_at_0(self, x):
return sympy.Matrix(2, 1, lambda r, c:
sympy.diff((self * So2.exp(x))[r], x))\
.limit(x, 0)
@staticmethod
def Dxi_x_matrix(x, i):
if i == 0:
return sympy.Matrix([[1, 0],
[0, 1]])
if i == 1:
return sympy.Matrix([[0, -1],
[1, 0]])
@staticmethod
def calc_Dxi_x_matrix(x, i):
return sympy.Matrix(2, 2, lambda r, c:
sympy.diff(x.matrix()[r, c], x[i]))
@staticmethod
def Dx_exp_x_matrix(x):
R = So2.exp(x)
Dx_exp_x = So2.calc_Dx_exp_x(x)
l = [Dx_exp_x[j] * So2.Dxi_x_matrix(R, j) for j in [0, 1]]
return functools.reduce((lambda a, b: a + b), l)
@staticmethod
def calc_Dx_exp_x_matrix(x):
return sympy.Matrix(2, 2, lambda r, c:
sympy.diff(So2.exp(x).matrix()[r, c], x))
@staticmethod
def Dx_exp_x_matrix_at_0():
return So2.hat(1)
@staticmethod
def calc_Dx_exp_x_matrix_at_0(x):
return sympy.Matrix(2, 2, lambda r, c:
sympy.diff(So2.exp(x).matrix()[r, c], x)
).limit(x, 0)
class TestSo2(unittest.TestCase):
def setUp(self):
self.theta = sympy.symbols(
'theta', real=True)
x, y = sympy.symbols('c[0] c[1]', real=True)
p0, p1 = sympy.symbols('p0 p1', real=True)
self.a = So2(sophus.Complex(x, y))
self.p = sophus.Vector2(p0, p1)
def test_exp_log(self):
for theta in [0., 0.5, 0.1]:
w = So2.exp(theta).log()
self.assertAlmostEqual(theta, w)
def test_matrix(self):
R_foo_bar = So2.exp(self.theta)
Rmat_foo_bar = R_foo_bar.matrix()
point_bar = self.p
p1_foo = R_foo_bar * point_bar
p2_foo = Rmat_foo_bar * point_bar
self.assertEqual(sympy.simplify(p1_foo - p2_foo),
sophus.ZeroVector2())
def test_derivatives(self):
self.assertEqual(sympy.simplify(So2.calc_Dx_exp_x_at_0(self.theta) -
So2.Dx_exp_x_at_0()),
sympy.Matrix.zeros(2, 1))
for i in [0, 1]:
self.assertEqual(sympy.simplify(So2.calc_Dxi_x_matrix(self.a, i) -
So2.Dxi_x_matrix(self.a, i)),
sympy.Matrix.zeros(2, 2))
self.assertEqual(sympy.simplify(
So2.Dx_exp_x_matrix(self.theta) -
So2.calc_Dx_exp_x_matrix(self.theta)),
sympy.Matrix.zeros(2, 2))
self.assertEqual(sympy.simplify(
So2.Dx_exp_x_matrix_at_0() -
So2.calc_Dx_exp_x_matrix_at_0(self.theta)),
sympy.Matrix.zeros(2, 2))
def test_codegen(self):
stream = sophus.cse_codegen(So2.calc_Dx_exp_x(self.theta))
filename = "cpp_gencode/So2_Dx_exp_x.cpp"
# set to true to generate codegen files
if False:
file = open(filename, "w")
for line in stream:
file.write(line)
file.close()
else:
file = open(filename, "r")
file_lines = file.readlines()
for i, line in enumerate(stream):
self.assertEqual(line, file_lines[i])
file.close()
stream.close
stream = sophus.cse_codegen(
self.a.calc_Dx_this_mul_exp_x_at_0(self.theta))
filename = "cpp_gencode/So2_Dx_this_mul_exp_x_at_0.cpp"
# set to true to generate codegen files
if False:
file = open(filename, "w")
for line in stream:
file.write(line)
file.close()
else:
file = open(filename, "r")
file_lines = file.readlines()
for i, line in enumerate(stream):
self.assertEqual(line, file_lines[i])
file.close()
stream.close
if __name__ == '__main__':
unittest.main()