Correct exmap is indeed correct, but derivatives *still* do not check out. I'm starting to suspect numericalDerivative.

release/4.3a0
Frank Dellaert 2010-03-02 17:56:26 +00:00
parent 32beb8c712
commit 190e87afb9
3 changed files with 144 additions and 55 deletions

View File

@ -46,17 +46,24 @@ namespace gtsam {
#ifdef SLOW_BUT_CORRECT_EXPMAP
/** Agrawal06iros versions of expmap and logmap*/
template<> Pose3 expmap(const Vector& d) {
Vector w = vector_range<const Vector>(d, range(0,3));
Vector u = vector_range<const Vector>(d, range(3,6));
double t = norm_2(w);
if (t < 1e-5)
return Pose3(Rot3(), expmap<Point3> (u));
/** Modified from Murray94book version (which assumes w and v normalized?) */
template<> Pose3 expmap(const Vector& xi) {
// get angular velocity omega and translational velocity v from twist xi
Point3 w(xi(0),xi(1),xi(2)), v(xi(3),xi(4),xi(5));
double theta = norm(w);
if (theta < 1e-5) {
static const Rot3 I;
return Pose3(I, v);
}
else {
Matrix W = skewSymmetric(w/t);
Matrix A = I3 + ((1 - cos(t)) / t) * W + ((t - sin(t)) / t) * (W * W);
return Pose3(expmap<Rot3> (w), expmap<Point3> (A * u));
Point3 n(w/theta); // axis unit vector
Rot3 R = rodriguez(n.vector(),theta);
double vn = dot(n,v); // translation parallel to n
Point3 n_cross_v = cross(n,v); // points towards axis
Point3 t = (n_cross_v - R*n_cross_v)/theta + vn*n;
return Pose3(R, t);
}
}
@ -67,7 +74,7 @@ namespace gtsam {
return concatVectors(2, &w, &T);
else {
Matrix W = skewSymmetric(w/t);
Matrix Ainv = I3 - 0.5*t* W + ((2*sin(t)-t*(1+cos(t)))/2*sin(t)) * (W * W);
Matrix Ainv = I3 - (0.5*t)*W + ((2*sin(t)-t*(1+cos(t)))/(2*sin(t))) * (W * W);
Vector u = Ainv*T;
return concatVectors(2, &w, &u);
}
@ -152,7 +159,7 @@ namespace gtsam {
Matrix Dcompose1(const Pose3& p1, const Pose3& p2) {
#ifdef SLOW_BUT_CORRECT_EXPMAP
// actually does NOT pan out at the moment
return AdjointMap(p2);
return AdjointMap(inverse(p2));
#else
const Rot3& R2 = p2.rotation();
const Point3& t2 = p2.translation();

View File

@ -172,4 +172,11 @@ namespace gtsam {
return wedge(xi(0),xi(1),xi(2),xi(3),xi(4),xi(5));
}
/**
* Calculate Adjoint map
* Ad_pose is 6*6 matrix that when applied to twist xi, returns Ad_pose(xi)
*/
Matrix AdjointMap(const Pose3& p);
inline Vector Adjoint(const Pose3& p, const Vector& xi) {return AdjointMap(p)*xi; }
} // namespace gtsam

View File

@ -3,30 +3,29 @@
* @brief Unit tests for Pose3 class
*/
#include <math.h>
#include <CppUnitLite/TestHarness.h>
#include "numericalDerivative.h"
#include "Pose3.h"
using namespace std;
using namespace gtsam;
Rot3 R = rodriguez(0.3,0,0);
Point3 t(3.5,-8.2,4.2);
Pose3 T(R,t);
Point3 P(0.2,0.7,-2);
Rot3 r1 = rodriguez(-90, 0, 0);
Pose3 pose1(r1, Point3(1, 2, 3));
static Point3 P(0.2,0.7,-2);
static Rot3 R = rodriguez(0.3,0,0);
static Pose3 T(R,Point3(3.5,-8.2,4.2));
static Pose3 T2(rodriguez(0.3,0.2,0.1),Point3(3.5,-8.2,4.2));
static Pose3 T3(rodriguez(-90, 0, 0), Point3(1, 2, 3));
double error = 1e-8;
#define PI 3.14159265358979323846
/* ************************************************************************* */
TEST( Pose3, equals)
{
Pose3 pose2 = pose1;
CHECK(pose1.equals(pose2));
Pose3 pose2 = T3;
CHECK(T3.equals(pose2));
Pose3 origin;
CHECK(!pose1.equals(origin));
CHECK(!T3.equals(origin));
}
/* ************************************************************************* */
@ -50,13 +49,14 @@ TEST(Pose3, expmap_b)
CHECK(assert_equal(expected, p2));
}
/* ************************************************************************* *
#ifdef SLOW_BUT_CORRECT_EXPMAP
/* ************************************************************************* */
// test case for screw motion in the plane
namespace screw {
double a=0.3, c=cos(a), s=sin(a), w=0.3;
Vector xi = Vector_(6, 0.0, 0.0, w, w, 0.0, 0.0);
Vector xi = Vector_(6, 0.0, 0.0, w, w, 0.0, 1.0);
Rot3 expectedR(c, -s, 0, s, c, 0, 0, 0, 1);
Point3 expectedT(0.29552, 0.0446635, 0);
Point3 expectedT(0.29552, 0.0446635, 1);
Pose3 expected(expectedR, expectedT);
}
@ -66,34 +66,114 @@ TEST(Pose3, expmap_c)
CHECK(assert_equal(screw::expected, expmap<Pose3>(screw::xi),1e-6));
}
/* ************************************************************************* */
// assert that T*exp(xi)*T^-1 is equal to exp(Ad_T(xi))
TEST(Pose3, Adjoint)
{
// assert that T*exp(xi)*T^-1
Pose3 expected = T * expmap<Pose3>(screw::xi) * inverse(T);
// is equal to exp(Ad_T(xi))
Vector xiprime = Adjoint(T, screw::xi);
CHECK(assert_equal(expected, expmap<Pose3>(xiprime), 1e-6));
Pose3 expected2 = T2 * expmap<Pose3>(screw::xi) * inverse(T2);
Vector xiprime2 = Adjoint(T2, screw::xi);
CHECK(assert_equal(expected2, expmap<Pose3>(xiprime2), 1e-6));
Pose3 expected3 = T3 * expmap<Pose3>(screw::xi) * inverse(T3);
Vector xiprime3 = Adjoint(T3, screw::xi);
CHECK(assert_equal(expected3, expmap<Pose3>(xiprime3), 1e-6));
}
/* ************************************************************************* */
/** Agrawal06iros version */
using namespace boost::numeric::ublas;
Pose3 Agrawal06iros(const Vector& xi) {
Vector w = vector_range<const Vector>(xi, range(0,3));
Vector v = vector_range<const Vector>(xi, range(3,6));
double t = norm_2(w);
if (t < 1e-5)
return Pose3(Rot3(), expmap<Point3> (v));
else {
Matrix W = skewSymmetric(w/t);
Matrix A = eye(3) + ((1 - cos(t)) / t) * W + ((t - sin(t)) / t) * (W * W);
return Pose3(expmap<Rot3> (w), expmap<Point3> (A * v));
}
}
/* ************************************************************************* */
TEST(Pose3, expmaps_galore)
{
Vector xi; Pose3 actual;
xi = Vector_(6,0.1,0.2,0.3,0.4,0.5,0.6);
actual = expmap<Pose3>(xi);
CHECK(assert_equal(expm<Pose3>(xi), actual,1e-6));
CHECK(assert_equal(Agrawal06iros(xi), actual,1e-6));
CHECK(assert_equal(xi, logmap(actual),1e-6));
xi = Vector_(6,0.1,-0.2,0.3,-0.4,0.5,-0.6);
for (double theta=1.0;0.3*theta<=M_PI;theta*=2) {
Vector txi = xi*theta;
actual = expmap<Pose3>(txi);
CHECK(assert_equal(expm<Pose3>(txi,30), actual,1e-6));
CHECK(assert_equal(Agrawal06iros(txi), actual,1e-6));
Vector log = logmap(actual);
CHECK(assert_equal(actual, expmap<Pose3>(log),1e-6));
CHECK(assert_equal(txi,log,1e-6)); // not true once wraps
}
// Works with large v as well, but expm needs 10 iterations!
xi = Vector_(6,0.2,0.3,-0.8,100.0,120.0,-60.0);
actual = expmap<Pose3>(xi);
CHECK(assert_equal(expm<Pose3>(xi,10), actual,1e-5));
CHECK(assert_equal(Agrawal06iros(xi), actual,1e-6));
CHECK(assert_equal(xi, logmap(actual),1e-6));
}
/* ************************************************************************* */
TEST(Pose3, Adjoint_compose)
{
// To debug derivatives of compose, assert that
// T1*T2*exp(Adjoint(inv(T2),x) = T1*exp(x)*T2
const Pose3& T1 = T;
Vector x = Vector_(6,0.1,0.1,0.1,0.4,0.2,0.8);
Pose3 expected = T1 * expmap<Pose3>(x) * T2;
Vector y = Adjoint(inverse(T2), x);
Pose3 actual = T1 * T2 * expmap<Pose3>(y);
CHECK(assert_equal(expected, actual, 1e-6));
}
#endif // SLOW_BUT_CORRECT_EXMAP
/* ************************************************************************* */
TEST( Pose3, compose )
{
Rot3 R = rodriguez(0.3,0.2,0.1);
Point3 t(3.5,-8.2,4.2);
Pose3 T(R,t);
Matrix actual = (T*T).matrix();
Matrix expected = T.matrix()*T.matrix();
Matrix actual = (T2*T2).matrix();
Matrix expected = T2.matrix()*T2.matrix();
CHECK(assert_equal(actual,expected,error));
Matrix numericalH1 = numericalDerivative21<Pose3,Pose3,Pose3>(compose, T, T, 1e-5);
Matrix actualDcompose1 = Dcompose1(T, T);
Matrix numericalH1 = numericalDerivative21<Pose3,Pose3,Pose3>(compose, T2, T2, 1e-5);
Matrix actualDcompose1 = Dcompose1(T2, T2);
CHECK(assert_equal(numericalH1,actualDcompose1));
Matrix actualDcompose2 = Dcompose2(T, T);
Matrix numericalH2 = numericalDerivative22<Pose3,Pose3,Pose3>(compose, T, T, 1e-5);
CHECK(assert_equal(numericalH2,actualDcompose2));}
Matrix actualDcompose2 = Dcompose2(T2, T2);
Matrix numericalH2 = numericalDerivative22<Pose3,Pose3,Pose3>(compose, T2, T2, 1e-5);
CHECK(assert_equal(numericalH2,actualDcompose2));
}
/* ************************************************************************* */
TEST( Pose3, compose2 )
{
const Pose3& T1 = T;
Matrix actual = (T1*T2).matrix();
Matrix expected = T1.matrix()*T2.matrix();
CHECK(assert_equal(actual,expected,error));
Matrix numericalH1 = numericalDerivative21<Pose3,Pose3,Pose3>(compose, T1, T2, 1e-5);
Matrix actualDcompose1 = Dcompose1(T1, T2);
CHECK(assert_equal(numericalH1,actualDcompose1));
Matrix actualDcompose2 = Dcompose2(T1, T2);
Matrix numericalH2 = numericalDerivative22<Pose3,Pose3,Pose3>(compose, T1, T2, 1e-5);
CHECK(assert_equal(numericalH2,actualDcompose2));
}
/* ************************************************************************* */
TEST( Pose3, inverse)
{
@ -216,7 +296,7 @@ TEST( Pose3, transform_to)
/* ************************************************************************* */
TEST( Pose3, transform_from)
{
Point3 actual = transform_from(pose1, Point3());
Point3 actual = transform_from(T3, Point3());
Point3 expected = Point3(1.,2.,3.);
CHECK(assert_equal(expected, actual));
}
@ -224,7 +304,7 @@ TEST( Pose3, transform_from)
/* ************************************************************************* */
TEST( Pose3, transform_roundtrip)
{
Point3 actual = transform_from(pose1, transform_to(pose1, Point3(12., -0.11,7.0)));
Point3 actual = transform_from(T3, transform_to(T3, Point3(12., -0.11,7.0)));
Point3 expected(12., -0.11,7.0);
CHECK(assert_equal(expected, actual));
}
@ -233,15 +313,15 @@ TEST( Pose3, transform_roundtrip)
TEST( Pose3, transformPose_to_origin)
{
// transform to origin
Pose3 actual = pose1.transform_to(Pose3());
CHECK(assert_equal(pose1, actual, error));
Pose3 actual = T3.transform_to(Pose3());
CHECK(assert_equal(T3, actual, error));
}
/* ************************************************************************* */
TEST( Pose3, transformPose_to_itself)
{
// transform to itself
Pose3 actual = pose1.transform_to(pose1);
Pose3 actual = T3.transform_to(T3);
CHECK(assert_equal(Pose3(), actual, error));
}
@ -286,7 +366,7 @@ TEST(Pose3, manifold)
{
//cout << "manifold" << endl;
Pose3 t1 = T;
Pose3 t2 = pose1;
Pose3 t2 = T3;
Pose3 origin;
Vector d12 = logmap(t1, t2);
CHECK(assert_equal(t2, expmap(t1,d12)));
@ -320,23 +400,18 @@ TEST(Pose3, manifold)
/* ************************************************************************* */
TEST( Pose3, between )
{
Rot3 R = rodriguez(0.3,0.2,0.1);
Point3 t(3.5,-8.2,4.2);
Pose3 T(R,t);
Pose3 expected = inverse(T) * pose1;
Pose3 expected = inverse(T2) * T3;
Matrix actualDBetween1,actualDBetween2;
Pose3 actual = between(T, pose1, actualDBetween1,actualDBetween2);
Pose3 actual = between(T2, T3, actualDBetween1,actualDBetween2);
CHECK(assert_equal(expected,actual));
Matrix numericalH1 = numericalDerivative21(between<Pose3> , T, pose1, 1e-5);
Matrix numericalH1 = numericalDerivative21(between<Pose3> , T2, T3, 1e-5);
CHECK(assert_equal(numericalH1,actualDBetween1)); // chain rule does not work ??
Matrix numericalH2 = numericalDerivative22(between<Pose3> , T, pose1, 1e-5);
Matrix numericalH2 = numericalDerivative22(between<Pose3> , T2, T3, 1e-5);
CHECK(assert_equal(numericalH2,actualDBetween2));
}
/* ************************************************************************* */
int main(){ TestResult tr; return TestRegistry::runAllTests(tr);}
/* ************************************************************************* */