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small code optim

release/4.3a0
thduynguyen 2014-12-24 14:00:33 -05:00
parent 7dfbcc04e9
commit ea4e9a5ac6
1 changed files with 9 additions and 4 deletions
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13
gtsam/geometry/Pose2.cpp
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@ -137,6 +137,7 @@ Matrix3 Pose2::adjointMap(const Vector& v) {
/* ************************************************************************* */
Matrix3 Pose2::ExpmapDerivative(const Vector3& v) {
double alpha = v[2];
Matrix3 J;
if (fabs(alpha) > 1e-5) {
// Chirikjian11book2, pg. 36
/* !!!Warning!!! Compare Iserles05an, formula 2.42 and Chirikjian11book2 pg.26
@ -149,7 +150,7 @@ Matrix3 Pose2::ExpmapDerivative(const Vector3& v) {
*/
double sZalpha = sin(alpha)/alpha, c_1Zalpha = (cos(alpha)-1)/alpha;
double v1Zalpha = v[0]/alpha, v2Zalpha = v[1]/alpha;
return (Matrix(3,3) <<
J = (Matrix(3,3) <<
sZalpha, -c_1Zalpha, v1Zalpha + v2Zalpha*c_1Zalpha - v1Zalpha*sZalpha,
c_1Zalpha, sZalpha, -v1Zalpha*c_1Zalpha + v2Zalpha - v2Zalpha*sZalpha,
0, 0, 1).finished();
@ -157,30 +158,34 @@ Matrix3 Pose2::ExpmapDerivative(const Vector3& v) {
else {
// Thanks to Krunal: Apply L'Hospital rule to several times to
// compute the limits when alpha -> 0
return (Matrix(3,3) << 1,0,-0.5*v[1],
J = (Matrix(3,3) << 1,0,-0.5*v[1],
0,1, 0.5*v[0],
0,0, 1).finished();
}
return J;
}
/* ************************************************************************* */
Matrix3 Pose2::LogmapDerivative(const Vector3& v) {
double alpha = v[2];
Matrix3 J;
if (fabs(alpha) > 1e-5) {
double alphaInv = 1/alpha;
double halfCotHalfAlpha = 0.5*sin(alpha)/(1-cos(alpha));
double v1 = v[0], v2 = v[1];
return (Matrix(3,3) <<
J = (Matrix(3,3) <<
alpha*halfCotHalfAlpha, -0.5*alpha, v1*alphaInv - v1*halfCotHalfAlpha + 0.5*v2,
0.5*alpha, alpha*halfCotHalfAlpha, v2*alphaInv - 0.5*v1 - v2*halfCotHalfAlpha,
0, 0, 1).finished();
}
else {
return (Matrix(3,3) << 1,0, 0.5*v[1],
J = (Matrix(3,3) << 1,0, 0.5*v[1],
0,1, -0.5*v[0],
0,0, 1).finished();
}
return J;
}
/* ************************************************************************* */