gtsam/gtsam/linear/JacobianFactor.cpp

710 lines
25 KiB
C++

/* ----------------------------------------------------------------------------
* GTSAM Copyright 2010, Georgia Tech Research Corporation,
* Atlanta, Georgia 30332-0415
* All Rights Reserved
* Authors: Frank Dellaert, et al. (see THANKS for the full author list)
* See LICENSE for the license information
* -------------------------------------------------------------------------- */
/**
* @file JacobianFactor.cpp
* @author Richard Roberts
* @author Christian Potthast
* @author Frank Dellaert
* @date Dec 8, 2010
*/
#include <gtsam/linear/linearExceptions.h>
#include <gtsam/linear/GaussianConditional.h>
#include <gtsam/linear/JacobianFactor.h>
#include <gtsam/linear/HessianFactor.h>
#include <gtsam/linear/GaussianFactorGraph.h>
#include <gtsam/linear/VectorValues.h>
#include <gtsam/inference/VariableSlots.h>
#include <gtsam/inference/Ordering.h>
#include <gtsam/base/debug.h>
#include <gtsam/base/timing.h>
#include <gtsam/base/Matrix.h>
#include <gtsam/base/FastMap.h>
#include <gtsam/base/cholesky.h>
#include <boost/assign/list_of.hpp>
#include <boost/foreach.hpp>
#include <boost/format.hpp>
#include <boost/make_shared.hpp>
#include <boost/array.hpp>
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-variable"
#endif
#include <boost/bind.hpp>
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
#include <boost/range/algorithm/copy.hpp>
#include <boost/range/adaptor/indirected.hpp>
#include <boost/range/adaptor/map.hpp>
#include <cmath>
#include <sstream>
#include <stdexcept>
using namespace std;
using namespace boost::assign;
namespace gtsam {
/* ************************************************************************* */
JacobianFactor::JacobianFactor() :
Ab_(cref_list_of<1>(1), 0) {
getb().setZero();
}
/* ************************************************************************* */
JacobianFactor::JacobianFactor(const GaussianFactor& gf) {
// Copy the matrix data depending on what type of factor we're copying from
if (const JacobianFactor* rhs = dynamic_cast<const JacobianFactor*>(&gf))
*this = JacobianFactor(*rhs);
else if (const HessianFactor* rhs = dynamic_cast<const HessianFactor*>(&gf))
*this = JacobianFactor(*rhs);
else
throw std::invalid_argument(
"In JacobianFactor(const GaussianFactor& rhs), rhs is neither a JacobianFactor nor a HessianFactor");
}
/* ************************************************************************* */
JacobianFactor::JacobianFactor(const Vector& b_in) :
Ab_(cref_list_of<1>(1), b_in.size()) {
getb() = b_in;
}
/* ************************************************************************* */
JacobianFactor::JacobianFactor(Key i1, const Matrix& A1, const Vector& b,
const SharedDiagonal& model) {
fillTerms(cref_list_of<1>(make_pair(i1, A1)), b, model);
}
/* ************************************************************************* */
JacobianFactor::JacobianFactor(const Key i1, const Matrix& A1, Key i2,
const Matrix& A2, const Vector& b, const SharedDiagonal& model) {
fillTerms(cref_list_of<2>(make_pair(i1, A1))(make_pair(i2, A2)), b, model);
}
/* ************************************************************************* */
JacobianFactor::JacobianFactor(const Key i1, const Matrix& A1, Key i2,
const Matrix& A2, Key i3, const Matrix& A3, const Vector& b,
const SharedDiagonal& model) {
fillTerms(
cref_list_of<3>(make_pair(i1, A1))(make_pair(i2, A2))(make_pair(i3, A3)),
b, model);
}
/* ************************************************************************* */
JacobianFactor::JacobianFactor(const HessianFactor& factor) :
Base(factor), Ab_(
VerticalBlockMatrix::LikeActiveViewOf(factor.matrixObject(),
factor.rows())) {
// Copy Hessian into our matrix and then do in-place Cholesky
Ab_.full() = factor.matrixObject().full();
// Do Cholesky to get a Jacobian
size_t maxrank;
bool success;
boost::tie(maxrank, success) = choleskyCareful(Ab_.matrix());
// Check for indefinite system
if (!success)
throw IndeterminantLinearSystemException(factor.keys().front());
// Zero out lower triangle
Ab_.matrix().topRows(maxrank).triangularView<Eigen::StrictlyLower>() =
Matrix::Zero(maxrank, Ab_.matrix().cols());
// FIXME: replace with triangular system
Ab_.rowEnd() = maxrank;
model_ = SharedDiagonal(); // should be same as Unit::Create(maxrank);
}
/* ************************************************************************* */
// Helper functions for combine constructor
namespace {
boost::tuple<FastVector<DenseIndex>, DenseIndex, DenseIndex> _countDims(
const FastVector<JacobianFactor::shared_ptr>& factors,
const FastVector<VariableSlots::const_iterator>& variableSlots) {
gttic(countDims);
#ifdef GTSAM_EXTRA_CONSISTENCY_CHECKS
FastVector<DenseIndex> varDims(variableSlots.size(), numeric_limits<DenseIndex>::max());
#else
FastVector<DenseIndex> varDims(variableSlots.size(),
numeric_limits<DenseIndex>::max());
#endif
DenseIndex m = 0;
DenseIndex n = 0;
for (size_t jointVarpos = 0; jointVarpos < variableSlots.size();
++jointVarpos) {
const VariableSlots::const_iterator& slots = variableSlots[jointVarpos];
assert(slots->second.size() == factors.size());
bool foundVariable = false;
for (size_t sourceFactorI = 0; sourceFactorI < slots->second.size();
++sourceFactorI) {
const size_t sourceVarpos = slots->second[sourceFactorI];
if (sourceVarpos != VariableSlots::Empty) {
const JacobianFactor& sourceFactor = *factors[sourceFactorI];
if (sourceFactor.cols() > 1) {
foundVariable = true;
DenseIndex vardim = sourceFactor.getDim(
sourceFactor.begin() + sourceVarpos);
#ifdef GTSAM_EXTRA_CONSISTENCY_CHECKS
if(varDims[jointVarpos] == numeric_limits<DenseIndex>::max()) {
varDims[jointVarpos] = vardim;
n += vardim;
} else {
if(!(varDims[jointVarpos] == vardim)) {
cout << "Factor " << sourceFactorI << " variable " << DefaultKeyFormatter(sourceFactor.keys()[sourceVarpos]) <<
" has different dimensionality of " << vardim << " instead of " << varDims[jointVarpos] << endl;
exit(1);
}
}
#else
varDims[jointVarpos] = vardim;
n += vardim;
break;
#endif
}
}
}
if (!foundVariable)
throw std::invalid_argument(
"Unable to determine dimensionality for all variables");
}
BOOST_FOREACH(const JacobianFactor::shared_ptr& factor, factors) {
m += factor->rows();
}
#ifdef GTSAM_EXTRA_CONSISTENCY_CHECKS
BOOST_FOREACH(DenseIndex d, varDims) {
assert(d != numeric_limits<DenseIndex>::max());
}
#endif
return boost::make_tuple(varDims, m, n);
}
/* ************************************************************************* */
FastVector<JacobianFactor::shared_ptr> _convertOrCastToJacobians(
const GaussianFactorGraph& factors) {
gttic(Convert_to_Jacobians);
FastVector<JacobianFactor::shared_ptr> jacobians;
jacobians.reserve(factors.size());
BOOST_FOREACH(const GaussianFactor::shared_ptr& factor, factors) {
if (factor) {
if (JacobianFactor::shared_ptr jf = boost::dynamic_pointer_cast<
JacobianFactor>(factor))
jacobians.push_back(jf);
else
jacobians.push_back(boost::make_shared<JacobianFactor>(*factor));
}
}
return jacobians;
}
}
/* ************************************************************************* */
JacobianFactor::JacobianFactor(const GaussianFactorGraph& graph,
boost::optional<const Ordering&> ordering,
boost::optional<const VariableSlots&> variableSlots) {
gttic(JacobianFactor_combine_constructor);
// Compute VariableSlots if one was not provided
boost::optional<VariableSlots> computedVariableSlots;
if (!variableSlots) {
computedVariableSlots = VariableSlots(graph);
variableSlots = computedVariableSlots; // Binds reference, does not copy VariableSlots
}
// Cast or convert to Jacobians
FastVector<JacobianFactor::shared_ptr> jacobians = _convertOrCastToJacobians(
graph);
gttic(Order_slots);
// Order variable slots - we maintain the vector of ordered slots, as well as keep a list
// 'unorderedSlots' of any variables discovered that are not in the ordering. Those will then
// be added after all of the ordered variables.
FastVector<VariableSlots::const_iterator> orderedSlots;
orderedSlots.reserve(variableSlots->size());
if (ordering) {
// If an ordering is provided, arrange the slots first that ordering
FastList<VariableSlots::const_iterator> unorderedSlots;
size_t nOrderingSlotsUsed = 0;
orderedSlots.resize(ordering->size());
FastMap<Key, size_t> inverseOrdering = ordering->invert();
for (VariableSlots::const_iterator item = variableSlots->begin();
item != variableSlots->end(); ++item) {
FastMap<Key, size_t>::const_iterator orderingPosition =
inverseOrdering.find(item->first);
if (orderingPosition == inverseOrdering.end()) {
unorderedSlots.push_back(item);
} else {
orderedSlots[orderingPosition->second] = item;
++nOrderingSlotsUsed;
}
}
if (nOrderingSlotsUsed != ordering->size())
throw std::invalid_argument(
"The ordering provided to the JacobianFactor combine constructor\n"
"contained extra variables that did not appear in the factors to combine.");
// Add the remaining slots
BOOST_FOREACH(VariableSlots::const_iterator item, unorderedSlots) {
orderedSlots.push_back(item);
}
} else {
// If no ordering is provided, arrange the slots as they were, which will be sorted
// numerically since VariableSlots uses a map sorting on Key.
for (VariableSlots::const_iterator item = variableSlots->begin();
item != variableSlots->end(); ++item)
orderedSlots.push_back(item);
}
gttoc(Order_slots);
// Count dimensions
FastVector<DenseIndex> varDims;
DenseIndex m, n;
boost::tie(varDims, m, n) = _countDims(jacobians, orderedSlots);
// Allocate matrix and copy keys in order
gttic(allocate);
Ab_ = VerticalBlockMatrix(varDims, m, true); // Allocate augmented matrix
Base::keys_.resize(orderedSlots.size());
boost::range::copy(
// Get variable keys
orderedSlots | boost::adaptors::indirected | boost::adaptors::map_keys,
Base::keys_.begin());
gttoc(allocate);
// Loop over slots in combined factor and copy blocks from source factors
gttic(copy_blocks);
size_t combinedSlot = 0;
BOOST_FOREACH(VariableSlots::const_iterator varslot, orderedSlots) {
JacobianFactor::ABlock destSlot(this->getA(this->begin() + combinedSlot));
// Loop over source jacobians
DenseIndex nextRow = 0;
for (size_t factorI = 0; factorI < jacobians.size(); ++factorI) {
// Slot in source factor
const size_t sourceSlot = varslot->second[factorI];
const DenseIndex sourceRows = jacobians[factorI]->rows();
if (sourceRows > 0) {
JacobianFactor::ABlock::RowsBlockXpr destBlock(
destSlot.middleRows(nextRow, sourceRows));
// Copy if exists in source factor, otherwise set zero
if (sourceSlot != VariableSlots::Empty)
destBlock = jacobians[factorI]->getA(
jacobians[factorI]->begin() + sourceSlot);
else
destBlock.setZero();
nextRow += sourceRows;
}
}
++combinedSlot;
}
gttoc(copy_blocks);
// Copy the RHS vectors and sigmas
gttic(copy_vectors);
bool anyConstrained = false;
boost::optional<Vector> sigmas;
// Loop over source jacobians
DenseIndex nextRow = 0;
for (size_t factorI = 0; factorI < jacobians.size(); ++factorI) {
const DenseIndex sourceRows = jacobians[factorI]->rows();
if (sourceRows > 0) {
this->getb().segment(nextRow, sourceRows) = jacobians[factorI]->getb();
if (jacobians[factorI]->get_model()) {
// If the factor has a noise model and we haven't yet allocated sigmas, allocate it.
if (!sigmas)
sigmas = Vector::Constant(m, 1.0);
sigmas->segment(nextRow, sourceRows) =
jacobians[factorI]->get_model()->sigmas();
if (jacobians[factorI]->isConstrained())
anyConstrained = true;
}
nextRow += sourceRows;
}
}
gttoc(copy_vectors);
if (sigmas)
this->setModel(anyConstrained, *sigmas);
}
/* ************************************************************************* */
void JacobianFactor::print(const string& s,
const KeyFormatter& formatter) const {
if (!s.empty())
cout << s << "\n";
for (const_iterator key = begin(); key != end(); ++key) {
cout
<< formatMatrixIndented(
(boost::format(" A[%1%] = ") % formatter(*key)).str(), getA(key))
<< endl;
}
cout << formatMatrixIndented(" b = ", getb(), true) << "\n";
if (model_)
model_->print(" Noise model: ");
else
cout << " No noise model" << endl;
}
/* ************************************************************************* */
// Check if two linear factors are equal
bool JacobianFactor::equals(const GaussianFactor& f_, double tol) const {
static const bool verbose = false;
if (!dynamic_cast<const JacobianFactor*>(&f_)) {
if (verbose)
cout << "JacobianFactor::equals: Incorrect type" << endl;
return false;
} else {
const JacobianFactor& f(static_cast<const JacobianFactor&>(f_));
// Check keys
if (keys() != f.keys()) {
if (verbose)
cout << "JacobianFactor::equals: keys do not match" << endl;
return false;
}
// Check noise model
if ((model_ && !f.model_) || (!model_ && f.model_)) {
if (verbose)
cout << "JacobianFactor::equals: noise model mismatch" << endl;
return false;
}
if (model_ && f.model_ && !model_->equals(*f.model_, tol)) {
if (verbose)
cout << "JacobianFactor::equals: noise modesl are not equal" << endl;
return false;
}
// Check matrix sizes
if (!(Ab_.rows() == f.Ab_.rows() && Ab_.cols() == f.Ab_.cols())) {
if (verbose)
cout << "JacobianFactor::equals: augmented size mismatch" << endl;
return false;
}
// Check matrix contents
constABlock Ab1(Ab_.range(0, Ab_.nBlocks()));
constABlock Ab2(f.Ab_.range(0, f.Ab_.nBlocks()));
for (size_t row = 0; row < (size_t) Ab1.rows(); ++row)
if (!equal_with_abs_tol(Ab1.row(row), Ab2.row(row), tol)
&& !equal_with_abs_tol(-Ab1.row(row), Ab2.row(row), tol)) {
if (verbose)
cout << "JacobianFactor::equals: matrix mismatch at row " << row << endl;
return false;
}
return true;
}
}
/* ************************************************************************* */
Vector JacobianFactor::unweighted_error(const VectorValues& c) const {
Vector e = -getb();
for (size_t pos = 0; pos < size(); ++pos)
e += Ab_(pos) * c[keys_[pos]];
return e;
}
/* ************************************************************************* */
Vector JacobianFactor::error_vector(const VectorValues& c) const {
if (model_)
return model_->whiten(unweighted_error(c));
else
return unweighted_error(c);
}
/* ************************************************************************* */
double JacobianFactor::error(const VectorValues& c) const {
if (empty())
return 0;
Vector weighted = error_vector(c);
return 0.5 * weighted.dot(weighted);
}
/* ************************************************************************* */
Matrix JacobianFactor::augmentedInformation() const {
if (model_) {
Matrix AbWhitened = Ab_.full();
model_->WhitenInPlace(AbWhitened);
return AbWhitened.transpose() * AbWhitened;
} else {
return Ab_.full().transpose() * Ab_.full();
}
}
/* ************************************************************************* */
Matrix JacobianFactor::information() const {
if (model_) {
Matrix AWhitened = this->getA();
model_->WhitenInPlace(AWhitened);
return AWhitened.transpose() * AWhitened;
} else {
return this->getA().transpose() * this->getA();
}
}
/* ************************************************************************* */
VectorValues JacobianFactor::hessianDiagonal() const {
VectorValues d;
for (size_t pos = 0; pos < size(); ++pos) {
Key j = keys_[pos];
size_t nj = Ab_(pos).cols();
Vector dj(nj);
for (size_t k = 0; k < nj; ++k) {
Vector column_k = Ab_(pos).col(k);
if (model_)
column_k = model_->whiten(column_k);
dj(k) = dot(column_k, column_k);
}
d.insert(j, dj);
}
return d;
}
/* ************************************************************************* */
// Raw memory access version should be called in Regular Factors only currently
void JacobianFactor::hessianDiagonal(double* d) const {
throw std::runtime_error("JacobianFactor::hessianDiagonal raw memory access is allowed for Regular Factors only");
}
/* ************************************************************************* */
map<Key, Matrix> JacobianFactor::hessianBlockDiagonal() const {
map<Key, Matrix> blocks;
for (size_t pos = 0; pos < size(); ++pos) {
Key j = keys_[pos];
Matrix Aj = Ab_(pos);
if (model_)
Aj = model_->Whiten(Aj);
blocks.insert(make_pair(j, Aj.transpose() * Aj));
}
return blocks;
}
/* ************************************************************************* */
Vector JacobianFactor::operator*(const VectorValues& x) const {
Vector Ax = zero(Ab_.rows());
if (empty())
return Ax;
// Just iterate over all A matrices and multiply in correct config part
for (size_t pos = 0; pos < size(); ++pos)
Ax += Ab_(pos) * x[keys_[pos]];
return model_ ? model_->whiten(Ax) : Ax;
}
/* ************************************************************************* */
void JacobianFactor::transposeMultiplyAdd(double alpha, const Vector& e,
VectorValues& x) const {
Vector E = alpha * (model_ ? model_->whiten(e) : e);
// Just iterate over all A matrices and insert Ai^e into VectorValues
for (size_t pos = 0; pos < size(); ++pos) {
Key j = keys_[pos];
// Create the value as a zero vector if it does not exist.
pair<VectorValues::iterator, bool> xi = x.tryInsert(j, Vector());
if (xi.second)
xi.first->second = Vector::Zero(getDim(begin() + pos));
gtsam::transposeMultiplyAdd(Ab_(pos), E, xi.first->second);
}
}
/* ************************************************************************* */
void JacobianFactor::multiplyHessianAdd(double alpha, const VectorValues& x,
VectorValues& y) const {
Vector Ax = (*this) * x;
transposeMultiplyAdd(alpha, Ax, y);
}
/* ************************************************************************* */
VectorValues JacobianFactor::gradientAtZero() const {
VectorValues g;
Vector b = getb();
// Gradient is really -A'*b / sigma^2
// transposeMultiplyAdd will divide by sigma once, so we need one more
Vector b_sigma = model_ ? model_->whiten(b) : b;
this->transposeMultiplyAdd(-1.0, b_sigma, g); // g -= A'*b/sigma^2
return g;
}
/* ************************************************************************* */
// Raw memory access version should be called in Regular Factors only currently
void JacobianFactor::gradientAtZero(double* d) const {
throw std::runtime_error("JacobianFactor::gradientAtZero raw memory access is allowed for Regular Factors only");
}
/* ************************************************************************* */
Vector JacobianFactor::gradient(Key key, const VectorValues& x) const {
// TODO: optimize it for JacobianFactor without converting to a HessianFactor
HessianFactor hessian(*this);
return hessian.gradient(key, x);
}
/* ************************************************************************* */
pair<Matrix, Vector> JacobianFactor::jacobian() const {
pair<Matrix, Vector> result = jacobianUnweighted();
// divide in sigma so error is indeed 0.5*|Ax-b|
if (model_)
model_->WhitenSystem(result.first, result.second);
return result;
}
/* ************************************************************************* */
pair<Matrix, Vector> JacobianFactor::jacobianUnweighted() const {
Matrix A(Ab_.range(0, size()));
Vector b(getb());
return make_pair(A, b);
}
/* ************************************************************************* */
Matrix JacobianFactor::augmentedJacobian() const {
Matrix Ab = augmentedJacobianUnweighted();
if (model_)
model_->WhitenInPlace(Ab);
return Ab;
}
/* ************************************************************************* */
Matrix JacobianFactor::augmentedJacobianUnweighted() const {
return Ab_.range(0, Ab_.nBlocks());
}
/* ************************************************************************* */
JacobianFactor JacobianFactor::whiten() const {
JacobianFactor result(*this);
if (model_) {
result.model_->WhitenInPlace(result.Ab_.full());
result.model_ = SharedDiagonal();
}
return result;
}
/* ************************************************************************* */
GaussianFactor::shared_ptr JacobianFactor::negate() const {
HessianFactor hessian(*this);
return hessian.negate();
}
/* ************************************************************************* */
std::pair<boost::shared_ptr<GaussianConditional>,
boost::shared_ptr<JacobianFactor> > JacobianFactor::eliminate(
const Ordering& keys) {
GaussianFactorGraph graph;
graph.add(*this);
return EliminateQR(graph, keys);
}
/* ************************************************************************* */
void JacobianFactor::setModel(bool anyConstrained, const Vector& sigmas) {
if ((size_t) sigmas.size() != this->rows())
throw InvalidNoiseModel(this->rows(), sigmas.size());
if (anyConstrained)
model_ = noiseModel::Constrained::MixedSigmas(sigmas);
else
model_ = noiseModel::Diagonal::Sigmas(sigmas);
}
/* ************************************************************************* */
std::pair<boost::shared_ptr<GaussianConditional>,
boost::shared_ptr<JacobianFactor> > EliminateQR(
const GaussianFactorGraph& factors, const Ordering& keys) {
gttic(EliminateQR);
// Combine and sort variable blocks in elimination order
JacobianFactor::shared_ptr jointFactor;
try {
jointFactor = boost::make_shared<JacobianFactor>(factors, keys);
} catch (std::invalid_argument&) {
throw InvalidDenseElimination(
"EliminateQR was called with a request to eliminate variables that are not\n"
"involved in the provided factors.");
}
// Do dense elimination
SharedDiagonal noiseModel;
if (jointFactor->model_)
jointFactor->model_ = jointFactor->model_->QR(jointFactor->Ab_.matrix());
else
inplace_QR(jointFactor->Ab_.matrix());
// Zero below the diagonal
jointFactor->Ab_.matrix().triangularView<Eigen::StrictlyLower>().setZero();
// Split elimination result into conditional and remaining factor
GaussianConditional::shared_ptr conditional = jointFactor->splitConditional(
keys.size());
return make_pair(conditional, jointFactor);
}
/* ************************************************************************* */
GaussianConditional::shared_ptr JacobianFactor::splitConditional(
size_t nrFrontals) {
gttic(JacobianFactor_splitConditional);
if (nrFrontals > size())
throw std::invalid_argument(
"Requesting to split more variables than exist using JacobianFactor::splitConditional");
DenseIndex frontalDim = Ab_.range(0, nrFrontals).cols();
// Restrict the matrix to be in the first nrFrontals variables and create the conditional
gttic(cond_Rd);
const DenseIndex originalRowEnd = Ab_.rowEnd();
Ab_.rowEnd() = Ab_.rowStart() + frontalDim;
SharedDiagonal conditionalNoiseModel;
if (model_) {
if ((DenseIndex) model_->dim() < frontalDim)
throw IndeterminantLinearSystemException(this->keys().front());
conditionalNoiseModel = noiseModel::Diagonal::Sigmas(
model_->sigmas().segment(Ab_.rowStart(), Ab_.rows()));
}
GaussianConditional::shared_ptr conditional = boost::make_shared<
GaussianConditional>(Base::keys_, nrFrontals, Ab_, conditionalNoiseModel);
const DenseIndex maxRemainingRows = std::min(Ab_.cols() - 1, originalRowEnd)
- Ab_.rowStart() - frontalDim;
const DenseIndex remainingRows =
model_ ?
std::min(model_->sigmas().size() - frontalDim, maxRemainingRows) :
maxRemainingRows;
Ab_.rowStart() += frontalDim;
Ab_.rowEnd() = Ab_.rowStart() + remainingRows;
Ab_.firstBlock() += nrFrontals;
gttoc(cond_Rd);
// Take lower-right block of Ab to get the new factor
gttic(remaining_factor);
keys_.erase(begin(), begin() + nrFrontals);
// Set sigmas with the right model
if (model_) {
if (model_->isConstrained())
model_ = noiseModel::Constrained::MixedSigmas(
model_->sigmas().tail(remainingRows));
else
model_ = noiseModel::Diagonal::Sigmas(
model_->sigmas().tail(remainingRows));
assert(model_->dim() == (size_t)Ab_.rows());
}
gttoc(remaining_factor);
return conditional;
}
}