gtsam/base/numericalDerivative.h

250 lines
8.6 KiB
C++

/**
* @file numericalDerivative.h
* @brief Some functions to compute numerical derivatives
* @author Frank Dellaert
*/
// \callgraph
#pragma once
#include <boost/function.hpp>
#include <boost/bind.hpp>
#include "Lie.h"
#include "Matrix.h"
//#define LINEARIZE_AT_IDENTITY
namespace gtsam {
/*
* Note that all of these functions have two versions, a boost.function version and a
* standard C++ function pointer version. This allows reformulating the arguments of
* a function to fit the correct structure, which is useful for situations like
* member functions and functions with arguments not involved in the derivative:
*
* Usage of the boost bind version to rearrange arguments:
* for a function with one relevant param and an optional derivative:
* Foo bar(const Obj& a, boost::optional<Matrix&> H1)
* Use boost.bind to restructure:
* boost::bind(bar, _1, boost::none)
* This syntax will fix the optional argument to boost::none, while using the first argument provided
*
* For member functions, such as below, with an instantiated copy instanceOfSomeClass
* Foo SomeClass::bar(const Obj& a)
* Use boost bind as follows to create a function pointer that uses the member function:
* boost::bind(&SomeClass::bar, ref(instanceOfSomeClass), _1)
*
* For additional details, see the documentation:
* http://www.boost.org/doc/libs/1_43_0/libs/bind/bind.html
*/
/**
* Numerically compute gradient of scalar function
* Class X is the input argument
* The class X needs to have dim, expmap, logmap
*/
template<class X>
Vector numericalGradient(boost::function<double(const X&)> h, const X& x, double delta=1e-5) {
double factor = 1.0/(2.0*delta);
const size_t n = x.dim();
Vector d(n,0.0), g(n,0.0);
for (size_t j=0;j<n;j++) {
d(j) += delta; double hxplus = h(expmap(x,d));
d(j) -= 2*delta; double hxmin = h(expmap(x,d));
d(j) += delta; g(j) = (hxplus-hxmin)*factor;
}
return g;
}
template<class X>
Vector numericalGradient(double (*h)(const X&), const X& x, double delta=1e-5) {
return numericalGradient<X>(boost::bind(h, _1), x, delta);
}
/**
* Compute numerical derivative in argument 1 of unary function
* @param h unary function yielding m-vector
* @param x n-dimensional value at which to evaluate h
* @param delta increment for numerical derivative
* Class Y is the output argument
* Class X is the input argument
* @return m*n Jacobian computed via central differencing
* Both classes X,Y need dim, expmap, logmap
*/
template<class Y, class X>
Matrix numericalDerivative11(boost::function<Y(const X&)> h, const X& x, double delta=1e-5) {
Y hx = h(x);
double factor = 1.0/(2.0*delta);
const size_t m = dim(hx), n = dim(x);
Vector d(n,0.0);
Matrix H = zeros(m,n);
for (size_t j=0;j<n;j++) {
d(j) += delta; Vector hxplus = logmap(hx, h(expmap(x,d)));
d(j) -= 2*delta; Vector hxmin = logmap(hx, h(expmap(x,d)));
d(j) += delta; Vector dh = (hxplus-hxmin)*factor;
for (size_t i=0;i<m;i++) H(i,j) = dh(i);
}
return H;
}
template<class Y, class X>
Matrix numericalDerivative11(Y (*h)(const X&), const X& x, double delta=1e-5) {
return numericalDerivative11<Y,X>(boost::bind(h, _1), x, delta);
}
/**
* Compute numerical derivative in argument 1 of binary function
* @param h binary function yielding m-vector
* @param x1 n-dimensional first argument value
* @param x2 second argument value
* @param delta increment for numerical derivative
* @return m*n Jacobian computed via central differencing
* All classes Y,X1,X2 need dim, expmap, logmap
*/
template<class Y, class X1, class X2>
Matrix numericalDerivative21(boost::function<Y(const X1&, const X2&)> h,
const X1& x1, const X2& x2, double delta=1e-5) {
Y hx = h(x1,x2);
double factor = 1.0/(2.0*delta);
const size_t m = dim(hx), n = dim(x1);
Vector d(n,0.0);
Matrix H = zeros(m,n);
for (size_t j=0;j<n;j++) {
d(j) += delta; Vector hxplus = logmap(hx, h(expmap(x1,d),x2));
d(j) -= 2*delta; Vector hxmin = logmap(hx, h(expmap(x1,d),x2));
d(j) += delta; Vector dh = (hxplus-hxmin)*factor;
for (size_t i=0;i<m;i++) H(i,j) = dh(i);
}
return H;
}
template<class Y, class X1, class X2>
Matrix numericalDerivative21(Y (*h)(const X1&, const X2&),
const X1& x1, const X2& x2, double delta=1e-5) {
return numericalDerivative21<Y,X1,X2>(boost::bind(h, _1, _2), x1, x2, delta);
}
/**
* Compute numerical derivative in argument 2 of binary function
* @param h binary function yielding m-vector
* @param x1 first argument value
* @param x2 n-dimensional second argument value
* @param delta increment for numerical derivative
* @return m*n Jacobian computed via central differencing
* All classes Y,X1,X2 need dim, expmap, logmap
*/
template<class Y, class X1, class X2>
Matrix numericalDerivative22
(boost::function<Y(const X1&, const X2&)> h,
const X1& x1, const X2& x2, double delta=1e-5)
{
Y hx = h(x1,x2);
double factor = 1.0/(2.0*delta);
const size_t m = dim(hx), n = dim(x2);
Vector d(n,0.0);
Matrix H = zeros(m,n);
for (size_t j=0;j<n;j++) {
d(j) += delta; Vector hxplus = logmap(hx, h(x1,expmap(x2,d)));
d(j) -= 2*delta; Vector hxmin = logmap(hx, h(x1,expmap(x2,d)));
d(j) += delta; Vector dh = (hxplus-hxmin)*factor;
for (size_t i=0;i<m;i++) H(i,j) = dh(i);
}
return H;
}
template<class Y, class X1, class X2>
Matrix numericalDerivative22
(Y (*h)(const X1&, const X2&),
const X1& x1, const X2& x2, double delta=1e-5) {
return numericalDerivative22<Y,X1,X2>(boost::bind(h, _1, _2), x1, x2, delta);
}
/**
* Compute numerical derivative in argument 1 of ternary function
* @param h ternary function yielding m-vector
* @param x1 n-dimensional first argument value
* @param x2 second argument value
* @param x3 third argument value
* @param delta increment for numerical derivative
* @return m*n Jacobian computed via central differencing
* All classes Y,X1,X2,X3 need dim, expmap, logmap
*/
template<class Y, class X1, class X2, class X3>
Matrix numericalDerivative31
(boost::function<Y(const X1&, const X2&, const X3&)> h,
const X1& x1, const X2& x2, const X3& x3, double delta=1e-5)
{
Y hx = h(x1,x2,x3);
double factor = 1.0/(2.0*delta);
const size_t m = dim(hx), n = dim(x1);
Vector d(n,0.0);
Matrix H = zeros(m,n);
for (size_t j=0;j<n;j++) {
d(j) += delta; Vector hxplus = logmap(hx, h(expmap(x1,d),x2,x3));
d(j) -= 2*delta; Vector hxmin = logmap(hx, h(expmap(x1,d),x2,x3));
d(j) += delta; Vector dh = (hxplus-hxmin)*factor;
for (size_t i=0;i<m;i++) H(i,j) = dh(i);
}
return H;
}
template<class Y, class X1, class X2, class X3>
Matrix numericalDerivative31
(Y (*h)(const X1&, const X2&, const X3&),
const X1& x1, const X2& x2, const X3& x3, double delta=1e-5) {
return numericalDerivative31<Y,X1,X2, X3>(boost::bind(h, _1, _2, _3), x1, x2, x3, delta);
}
// arg 2
template<class Y, class X1, class X2, class X3>
Matrix numericalDerivative32
(boost::function<Y(const X1&, const X2&, const X3&)> h,
const X1& x1, const X2& x2, const X3& x3, double delta=1e-5)
{
Y hx = h(x1,x2,x3);
double factor = 1.0/(2.0*delta);
const size_t m = dim(hx), n = dim(x2);
Vector d(n,0.0);
Matrix H = zeros(m,n);
for (size_t j=0;j<n;j++) {
d(j) += delta; Vector hxplus = logmap(hx, h(x1, expmap(x2,d),x3));
d(j) -= 2*delta; Vector hxmin = logmap(hx, h(x1, expmap(x2,d),x3));
d(j) += delta; Vector dh = (hxplus-hxmin)*factor;
for (size_t i=0;i<m;i++) H(i,j) = dh(i);
}
return H;
}
template<class Y, class X1, class X2, class X3>
Matrix numericalDerivative32
(Y (*h)(const X1&, const X2&, const X3&),
const X1& x1, const X2& x2, const X3& x3, double delta=1e-5) {
return numericalDerivative32<Y,X1,X2, X3>(boost::bind(h, _1, _2, _3), x1, x2, x3, delta);
}
// arg 3
template<class Y, class X1, class X2, class X3>
Matrix numericalDerivative33
(boost::function<Y(const X1&, const X2&, const X3&)> h,
const X1& x1, const X2& x2, const X3& x3, double delta=1e-5)
{
Y hx = h(x1,x2,x3);
double factor = 1.0/(2.0*delta);
const size_t m = dim(hx), n = dim(x3);
Vector d(n,0.0);
Matrix H = zeros(m,n);
for (size_t j=0;j<n;j++) {
d(j) += delta; Vector hxplus = logmap(hx, h(x1, x2, expmap(x3,d)));
d(j) -= 2*delta; Vector hxmin = logmap(hx, h(x1, x2, expmap(x3,d)));
d(j) += delta; Vector dh = (hxplus-hxmin)*factor;
for (size_t i=0;i<m;i++) H(i,j) = dh(i);
}
return H;
}
template<class Y, class X1, class X2, class X3>
Matrix numericalDerivative33
(Y (*h)(const X1&, const X2&, const X3&),
const X1& x1, const X2& x2, const X3& x3, double delta=1e-5) {
return numericalDerivative33<Y,X1,X2, X3>(boost::bind(h, _1, _2, _3), x1, x2, x3, delta);
}
}