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// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2016 Alec Jacobson <alecjacobson@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#pragma once
#include "min_quad_with_fixed.h"
#include "slice.h"
#include "is_symmetric.h"
#include "find.h"
#include "sparse.h"
#include "repmat.h"
#include "EPS.h"
#include "cat.h"
//#include <Eigen/SparseExtra>
// Bug in unsupported/Eigen/SparseExtra needs iostream first
#include <iostream>
#include <unsupported/Eigen/SparseExtra>
#include <cassert>
#include <cstdio>
#include "matlab_format.h"
#include <type_traits>
template <typename T, typename Derivedknown>
IGL_INLINE bool igl::min_quad_with_fixed_precompute(
const Eigen::SparseMatrix<T>& A2,
const Eigen::MatrixBase<Derivedknown> & known,
const Eigen::SparseMatrix<T>& Aeq,
const bool pd,
min_quad_with_fixed_data<T> & data
)
{
//#define MIN_QUAD_WITH_FIXED_CPP_DEBUG
using namespace Eigen;
using namespace std;
const Eigen::SparseMatrix<T> A = 0.5*A2;
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" pre"<<endl;
#endif
// number of rows
int n = A.rows();
// cache problem size
data.n = n;
int neq = Aeq.rows();
// default is to have 0 linear equality constraints
if(Aeq.size() != 0)
{
assert(n == Aeq.cols() && "#Aeq.cols() should match A.rows()");
}
assert(known.cols() == 1 && "known should be a vector");
assert(A.rows() == n && "A should be square");
assert(A.cols() == n && "A should be square");
// number of known rows
int kr = known.size();
assert((kr == 0 || known.minCoeff() >= 0)&& "known indices should be in [0,n)");
assert((kr == 0 || known.maxCoeff() < n) && "known indices should be in [0,n)");
assert(neq <= n && "Number of equality constraints should be less than DOFs");
// cache known
// FIXME: This is *NOT* generic and introduces a copy.
data.known = known.template cast<int>();
// get list of unknown indices
data.unknown.resize(n-kr);
std::vector<bool> unknown_mask;
unknown_mask.resize(n,true);
for(int i = 0;i<kr;i++)
{
unknown_mask[known(i, 0)] = false;
}
int u = 0;
for(int i = 0;i<n;i++)
{
if(unknown_mask[i])
{
data.unknown(u) = i;
u++;
}
}
// get list of lagrange multiplier indices
data.lagrange.resize(neq);
for(int i = 0;i<neq;i++)
{
data.lagrange(i) = n + i;
}
// cache unknown followed by lagrange indices
data.unknown_lagrange.resize(data.unknown.size()+data.lagrange.size());
// Would like to do:
//data.unknown_lagrange << data.unknown, data.lagrange;
// but Eigen can't handle empty vectors in comma initialization
// https://forum.kde.org/viewtopic.php?f=74&t=107974&p=364947#p364947
if(data.unknown.size() > 0)
{
data.unknown_lagrange.head(data.unknown.size()) = data.unknown;
}
if(data.lagrange.size() > 0)
{
data.unknown_lagrange.tail(data.lagrange.size()) = data.lagrange;
}
SparseMatrix<T> Auu;
slice(A,data.unknown,data.unknown,Auu);
assert(Auu.size() != 0 && Auu.rows() > 0 && "There should be at least one unknown.");
// Positive definiteness is *not* determined, rather it is given as a
// parameter
data.Auu_pd = pd;
if(data.Auu_pd)
{
// PD implies symmetric
data.Auu_sym = true;
// This is an annoying assertion unless EPS can be chosen in a nicer way.
//assert(is_symmetric(Auu,EPS<T>()));
assert(is_symmetric(Auu,1.0) &&
"Auu should be symmetric if positive definite");
}else
{
// determine if A(unknown,unknown) is symmetric and/or positive definite
VectorXi AuuI,AuuJ;
Matrix<T,Eigen::Dynamic,Eigen::Dynamic> AuuV;
find(Auu,AuuI,AuuJ,AuuV);
data.Auu_sym = is_symmetric(Auu,EPS<T>()*AuuV.maxCoeff());
}
// Determine number of linearly independent constraints
int nc = 0;
if(neq>0)
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" qr"<<endl;
#endif
// QR decomposition to determine row rank in Aequ
slice(Aeq,data.unknown,2,data.Aequ);
assert(data.Aequ.rows() == neq &&
"#Rows in Aequ should match #constraints");
assert(data.Aequ.cols() == data.unknown.size() &&
"#cols in Aequ should match #unknowns");
data.AeqTQR.compute(data.Aequ.transpose().eval());
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
//cout<<endl<<matlab_format(SparseMatrix<T>(data.Aequ.transpose().eval()),"AeqT")<<endl<<endl;
#endif
switch(data.AeqTQR.info())
{
case Eigen::Success:
break;
case Eigen::NumericalIssue:
cerr<<"Error: Numerical issue."<<endl;
return false;
case Eigen::InvalidInput:
cerr<<"Error: Invalid input."<<endl;
return false;
default:
cerr<<"Error: Other."<<endl;
return false;
}
nc = data.AeqTQR.rank();
assert(nc<=neq &&
"Rank of reduced constraints should be <= #original constraints");
data.Aeq_li = nc == neq;
//cout<<"data.Aeq_li: "<<data.Aeq_li<<endl;
}else
{
data.Aeq_li = true;
}
if(data.Aeq_li)
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" Aeq_li=true"<<endl;
#endif
// Append lagrange multiplier quadratic terms
SparseMatrix<T> new_A;
SparseMatrix<T> AeqT = Aeq.transpose();
SparseMatrix<T> Z(neq,neq);
// This is a bit slower. But why isn't cat fast?
new_A = cat(1, cat(2, A, AeqT ),
cat(2, Aeq, Z ));
// precompute RHS builders
if(kr > 0)
{
SparseMatrix<T> Aulk,Akul;
// Slow
slice(new_A,data.unknown_lagrange,data.known,Aulk);
//// This doesn't work!!!
//data.preY = Aulk + Akul.transpose();
// Slow
if(data.Auu_sym)
{
data.preY = Aulk*2;
}else
{
slice(new_A,data.known,data.unknown_lagrange,Akul);
SparseMatrix<T> AkulT = Akul.transpose();
data.preY = Aulk + AkulT;
}
}else
{
data.preY.resize(data.unknown_lagrange.size(),0);
}
// Positive definite and no equality constraints (Positive definiteness
// implies symmetric)
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" factorize"<<endl;
#endif
if(data.Auu_pd && neq == 0)
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" llt"<<endl;
#endif
data.llt.compute(Auu);
switch(data.llt.info())
{
case Eigen::Success:
break;
case Eigen::NumericalIssue:
cerr<<"Error: Numerical issue."<<endl;
return false;
default:
cerr<<"Error: Other."<<endl;
return false;
}
data.solver_type = min_quad_with_fixed_data<T>::LLT;
}else
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" ldlt/lu"<<endl;
#endif
// Either not PD or there are equality constraints
SparseMatrix<T> NA;
slice(new_A,data.unknown_lagrange,data.unknown_lagrange,NA);
data.NA = NA;
if(data.Auu_pd)
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" ldlt"<<endl;
#endif
data.ldlt.compute(NA);
switch(data.ldlt.info())
{
case Eigen::Success:
break;
case Eigen::NumericalIssue:
cerr<<"Error: Numerical issue."<<endl;
return false;
default:
cerr<<"Error: Other."<<endl;
return false;
}
data.solver_type = min_quad_with_fixed_data<T>::LDLT;
}else
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" lu"<<endl;
#endif
// Resort to LU
// Bottleneck >1/2
data.lu.compute(NA);
//std::cout<<"NA=["<<std::endl<<NA<<std::endl<<"];"<<std::endl;
switch(data.lu.info())
{
case Eigen::Success:
break;
case Eigen::NumericalIssue:
cerr<<"Error: Numerical issue."<<endl;
return false;
case Eigen::InvalidInput:
cerr<<"Error: Invalid Input."<<endl;
return false;
default:
cerr<<"Error: Other."<<endl;
return false;
}
data.solver_type = min_quad_with_fixed_data<T>::LU;
}
}
}else
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" Aeq_li=false"<<endl;
#endif
data.neq = neq;
const int nu = data.unknown.size();
//cout<<"nu: "<<nu<<endl;
//cout<<"neq: "<<neq<<endl;
//cout<<"nc: "<<nc<<endl;
//cout<<" matrixR"<<endl;
SparseMatrix<T> AeqTR,AeqTQ;
AeqTR = data.AeqTQR.matrixR();
// This shouldn't be necessary
AeqTR.prune(static_cast<T>(0.0));
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" matrixQ"<<endl;
#endif
// THIS IS ESSENTIALLY DENSE AND THIS IS BY FAR THE BOTTLENECK
// http://forum.kde.org/viewtopic.php?f=74&t=117500
AeqTQ = data.AeqTQR.matrixQ();
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" prune"<<endl;
cout<<" nnz: "<<AeqTQ.nonZeros()<<endl;
#endif
// This shouldn't be necessary
AeqTQ.prune(static_cast<T>(0.0));
//cout<<"AeqTQ: "<<AeqTQ.rows()<<" "<<AeqTQ.cols()<<endl;
//cout<<matlab_format(AeqTQ,"AeqTQ")<<endl;
//cout<<" perms"<<endl;
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" nnz: "<<AeqTQ.nonZeros()<<endl;
cout<<" perm"<<endl;
#endif
SparseMatrix<T> I(neq,neq);
I.setIdentity();
data.AeqTE = data.AeqTQR.colsPermutation() * I;
data.AeqTET = data.AeqTQR.colsPermutation().transpose() * I;
assert(AeqTR.rows() == nu && "#rows in AeqTR should match #unknowns");
assert(AeqTR.cols() == neq && "#cols in AeqTR should match #constraints");
assert(AeqTQ.rows() == nu && "#rows in AeqTQ should match #unknowns");
assert(AeqTQ.cols() == nu && "#cols in AeqTQ should match #unknowns");
//cout<<" slice"<<endl;
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" slice"<<endl;
#endif
data.AeqTQ1 = AeqTQ.topLeftCorner(nu,nc);
data.AeqTQ1T = data.AeqTQ1.transpose().eval();
// ALREADY TRIM (Not 100% sure about this)
data.AeqTR1 = AeqTR.topLeftCorner(nc,nc);
data.AeqTR1T = data.AeqTR1.transpose().eval();
//cout<<"AeqTR1T.size() "<<data.AeqTR1T.rows()<<" "<<data.AeqTR1T.cols()<<endl;
// Null space
data.AeqTQ2 = AeqTQ.bottomRightCorner(nu,nu-nc);
data.AeqTQ2T = data.AeqTQ2.transpose().eval();
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" proj"<<endl;
#endif
// Projected hessian
SparseMatrix<T> QRAuu = data.AeqTQ2T * Auu * data.AeqTQ2;
{
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" factorize"<<endl;
#endif
// QRAuu should always be PD
data.llt.compute(QRAuu);
switch(data.llt.info())
{
case Eigen::Success:
break;
case Eigen::NumericalIssue:
cerr<<"Error: Numerical issue."<<endl;
return false;
default:
cerr<<"Error: Other."<<endl;
return false;
}
data.solver_type = min_quad_with_fixed_data<T>::QR_LLT;
}
#ifdef MIN_QUAD_WITH_FIXED_CPP_DEBUG
cout<<" smash"<<endl;
#endif
// Known value multiplier
SparseMatrix<T> Auk;
slice(A,data.unknown,data.known,Auk);
SparseMatrix<T> Aku;
slice(A,data.known,data.unknown,Aku);
SparseMatrix<T> AkuT = Aku.transpose();
data.preY = Auk + AkuT;
// Needed during solve
data.Auu = Auu;
slice(Aeq,data.known,2,data.Aeqk);
assert(data.Aeqk.rows() == neq);
assert(data.Aeqk.cols() == data.known.size());
}
return true;
}
template <
typename T,
typename DerivedB,
typename DerivedY,
typename DerivedBeq,
typename DerivedZ,
typename Derivedsol>
IGL_INLINE bool igl::min_quad_with_fixed_solve(
const min_quad_with_fixed_data<T> & data,
const Eigen::MatrixBase<DerivedB> & B,
const Eigen::MatrixBase<DerivedY> & Y,
const Eigen::MatrixBase<DerivedBeq> & Beq,
Eigen::PlainObjectBase<DerivedZ> & Z,
Eigen::PlainObjectBase<Derivedsol> & sol)
{
using namespace std;
using namespace Eigen;
typedef Matrix<T,Dynamic,Dynamic> MatrixXT;
// number of known rows
int kr = data.known.size();
if(kr!=0)
{
assert(kr == Y.rows());
}
// number of columns to solve
int cols = Y.cols();
assert(B.cols() == 1 || B.cols() == cols);
assert(Beq.size() == 0 || Beq.cols() == 1 || Beq.cols() == cols);
// resize output
Z.resize(data.n,cols);
// Set known values
for(int i = 0;i < kr;i++)
{
for(int j = 0;j < cols;j++)
{
Z(data.known(i),j) = Y(i,j);
}
}
if(data.Aeq_li)
{
// number of lagrange multipliers aka linear equality constraints
int neq = data.lagrange.size();
// append lagrange multiplier rhs's
MatrixXT BBeq(B.rows() + Beq.rows(),cols);
if(B.size() > 0)
{
BBeq.topLeftCorner(B.rows(),cols) = B.replicate(1,B.cols()==cols?1:cols);
}
if(Beq.size() > 0)
{
BBeq.bottomLeftCorner(Beq.rows(),cols) = -2.0*Beq.replicate(1,Beq.cols()==cols?1:cols);
}
// Build right hand side
MatrixXT BBequlcols = BBeq(data.unknown_lagrange,Eigen::all);
MatrixXT NB;
if(kr == 0)
{
NB = BBequlcols;
}else
{
NB = data.preY * Y + BBequlcols;
}
//std::cout<<"NB=["<<std::endl<<NB<<std::endl<<"];"<<std::endl;
//cout<<matlab_format(NB,"NB")<<endl;
switch(data.solver_type)
{
case igl::min_quad_with_fixed_data<T>::LLT:
sol = data.llt.solve(NB);
break;
case igl::min_quad_with_fixed_data<T>::LDLT:
sol = data.ldlt.solve(NB);
break;
case igl::min_quad_with_fixed_data<T>::LU:
// Not a bottleneck
sol = data.lu.solve(NB);
break;
default:
cerr<<"Error: invalid solver type"<<endl;
return false;
}
//std::cout<<"sol=["<<std::endl<<sol<<std::endl<<"];"<<std::endl;
// Now sol contains sol/-0.5
sol *= -0.5;
// Now sol contains solution
// Place solution in Z
for(int i = 0;i<(sol.rows()-neq);i++)
{
for(int j = 0;j<sol.cols();j++)
{
Z(data.unknown_lagrange(i),j) = sol(i,j);
}
}
}else
{
assert(data.solver_type == min_quad_with_fixed_data<T>::QR_LLT);
MatrixXT eff_Beq;
// Adjust Aeq rhs to include known parts
eff_Beq =
//data.AeqTQR.colsPermutation().transpose() * (-data.Aeqk * Y + Beq);
data.AeqTET * (-data.Aeqk * Y + Beq.replicate(1,Beq.cols()==cols?1:cols));
// Where did this -0.5 come from? Probably the same place as above.
MatrixXT Bu = B(data.unknown,Eigen::all);
MatrixXT NB;
NB = -0.5*(Bu.replicate(1,B.cols()==cols?1:cols) + data.preY * Y);
// Trim eff_Beq
const int nc = data.AeqTQR.rank();
const int neq = Beq.rows();
eff_Beq = eff_Beq.topLeftCorner(nc,cols).eval();
data.AeqTR1T.template triangularView<Lower>().solveInPlace(eff_Beq);
// Now eff_Beq = (data.AeqTR1T \ (data.AeqTET * (-data.Aeqk * Y + Beq)))
MatrixXT lambda_0;
lambda_0 = data.AeqTQ1 * eff_Beq;
//cout<<matlab_format(lambda_0,"lambda_0")<<endl;
MatrixXT QRB;
QRB = -data.AeqTQ2T * (data.Auu * lambda_0) + data.AeqTQ2T * NB;
Derivedsol lambda;
lambda = data.llt.solve(QRB);
// prepare output
Derivedsol solu;
solu = data.AeqTQ2 * lambda + lambda_0;
// http://www.math.uh.edu/~rohop/fall_06/Chapter3.pdf
Derivedsol solLambda;
{
Derivedsol temp1,temp2;
temp1 = (data.AeqTQ1T * NB - data.AeqTQ1T * data.Auu * solu);
data.AeqTR1.template triangularView<Upper>().solveInPlace(temp1);
//cout<<matlab_format(temp1,"temp1")<<endl;
temp2 = Derivedsol::Zero(neq,cols);
temp2.topLeftCorner(nc,cols) = temp1;
//solLambda = data.AeqTQR.colsPermutation() * temp2;
solLambda = data.AeqTE * temp2;
}
// sol is [Z(unknown);Lambda]
assert(data.unknown.size() == solu.rows());
assert(cols == solu.cols());
assert(data.neq == neq);
assert(data.neq == solLambda.rows());
assert(cols == solLambda.cols());
sol.resize(data.unknown.size()+data.neq,cols);
sol.block(0,0,solu.rows(),solu.cols()) = solu;
sol.block(solu.rows(),0,solLambda.rows(),solLambda.cols()) = solLambda;
for(int u = 0;u<data.unknown.size();u++)
{
for(int j = 0;j<Z.cols();j++)
{
Z(data.unknown(u),j) = solu(u,j);
}
}
}
return true;
}
template <
typename T,
typename DerivedB,
typename DerivedY,
typename DerivedBeq,
typename DerivedZ>
IGL_INLINE bool igl::min_quad_with_fixed_solve(
const min_quad_with_fixed_data<T> & data,
const Eigen::MatrixBase<DerivedB> & B,
const Eigen::MatrixBase<DerivedY> & Y,
const Eigen::MatrixBase<DerivedBeq> & Beq,
Eigen::PlainObjectBase<DerivedZ> & Z)
{
Eigen::Matrix<typename DerivedZ::Scalar, Eigen::Dynamic, Eigen::Dynamic> sol;
return min_quad_with_fixed_solve(data,B,Y,Beq,Z,sol);
}
template <
typename T,
typename Derivedknown,
typename DerivedB,
typename DerivedY,
typename DerivedBeq,
typename DerivedZ>
IGL_INLINE bool igl::min_quad_with_fixed(
const Eigen::SparseMatrix<T>& A,
const Eigen::MatrixBase<DerivedB> & B,
const Eigen::MatrixBase<Derivedknown> & known,
const Eigen::MatrixBase<DerivedY> & Y,
const Eigen::SparseMatrix<T>& Aeq,
const Eigen::MatrixBase<DerivedBeq> & Beq,
const bool pd,
Eigen::PlainObjectBase<DerivedZ> & Z)
{
min_quad_with_fixed_data<T> data;
if(!min_quad_with_fixed_precompute(A,known,Aeq,pd,data))
{
return false;
}
return min_quad_with_fixed_solve(data,B,Y,Beq,Z);
}
template <typename Scalar, int n, int m, bool Hpd>
IGL_INLINE Eigen::Matrix<Scalar,n,1> igl::min_quad_with_fixed(
const Eigen::Matrix<Scalar,n,n> & H,
const Eigen::Matrix<Scalar,n,1> & f,
const Eigen::Array<bool,n,1> & k,
const Eigen::Matrix<Scalar,n,1> & bc,
const Eigen::Matrix<Scalar,m,n> & A,
const Eigen::Matrix<Scalar,m,1> & b)
{
const auto dyn_n = n == Eigen::Dynamic ? H.rows() : n;
const auto dyn_m = m == Eigen::Dynamic ? A.rows() : m;
constexpr const int nn = n == Eigen::Dynamic ? Eigen::Dynamic : n+m;
const auto dyn_nn = nn == Eigen::Dynamic ? dyn_n+dyn_m : nn;
if(dyn_m == 0)
{
return igl::min_quad_with_fixed<Scalar,n,Hpd>(H,f,k,bc);
}
// min_x ½ xᵀ H x + xᵀ f subject to A x = b and x(k) = bc(k)
// let zᵀ = [xᵀ λᵀ]
// min_z ½ zᵀ [H Aᵀ;A 0] z + zᵀ [f;-b] z(k) = bc(k)
const auto make_HH = [&]()
{
// Windows can't remember that nn is const.
constexpr const int nn = n == Eigen::Dynamic ? Eigen::Dynamic : n+m;
Eigen::Matrix<Scalar,nn,nn> HH =
Eigen::Matrix<Scalar,nn,nn>::Zero(dyn_nn,dyn_nn);
HH.topLeftCorner(dyn_n,dyn_n) = H;
HH.bottomLeftCorner(dyn_m,dyn_n) = A;
HH.topRightCorner(dyn_n,dyn_m) = A.transpose();
return HH;
};
const Eigen::Matrix<Scalar,nn,nn> HH = make_HH();
const auto make_ff = [&]()
{
// Windows can't remember that nn is const.
constexpr const int nn = n == Eigen::Dynamic ? Eigen::Dynamic : n+m;
Eigen::Matrix<Scalar,nn,1> ff(dyn_nn);
ff.head(dyn_n) = f;
ff.tail(dyn_m) = -b;
return ff;
};
const Eigen::Matrix<Scalar,nn,1> ff = make_ff();
const auto make_kk = [&]()
{
// Windows can't remember that nn is const.
constexpr const int nn = n == Eigen::Dynamic ? Eigen::Dynamic : n+m;
Eigen::Array<bool,nn,1> kk =
Eigen::Array<bool,nn,1>::Constant(dyn_nn,1,false);
kk.head(dyn_n) = k;
return kk;
};
const Eigen::Array<bool,nn,1> kk = make_kk();
const auto make_bcbc= [&]()
{
// Windows can't remember that nn is const.
constexpr const int nn = n == Eigen::Dynamic ? Eigen::Dynamic : n+m;
Eigen::Matrix<Scalar,nn,1> bcbc(dyn_nn);
bcbc.head(dyn_n) = bc;
return bcbc;
};
const Eigen::Matrix<Scalar,nn,1> bcbc = make_bcbc();
const Eigen::Matrix<Scalar,nn,1> xx =
min_quad_with_fixed<Scalar,nn,false>(HH,ff,kk,bcbc);
return xx.head(dyn_n);
}
template <typename Scalar, int n, bool Hpd>
IGL_INLINE Eigen::Matrix<Scalar,n,1> igl::min_quad_with_fixed(
const Eigen::Matrix<Scalar,n,n> & H,
const Eigen::Matrix<Scalar,n,1> & f,
const Eigen::Array<bool,n,1> & k,
const Eigen::Matrix<Scalar,n,1> & bc)
{
assert(H.isApprox(H.transpose(),1e-7));
assert(H.rows() == H.cols());
assert(H.rows() == f.size());
assert(H.rows() == k.size());
assert(H.rows() == bc.size());
const auto kcount = k.count();
// Everything fixed
if(kcount == (Eigen::Dynamic?H.rows():n))
{
return bc;
}
// Nothing fixed
if(kcount == 0)
{
// avoid function call
typedef Eigen::Matrix<Scalar,n,n> MatrixSn;
typedef typename
std::conditional<Hpd,Eigen::LLT<MatrixSn>,Eigen::CompleteOrthogonalDecomposition<MatrixSn>>::type
Solver;
return Solver(H).solve(-f);
}
// All-but-one fixed
if( (Eigen::Dynamic?H.rows():n)-kcount == 1)
{
// which one is not fixed?
int u = -1;
for(int i=0;i<k.size();i++){ if(!k(i)){ u=i; break; } }
assert(u>=0);
// min ½ x(u) Huu x(u) + x(u)(fu + H(u,k)bc(k))
// Huu x(u) = -(fu + H(u,k) bc(k))
// x(u) = (-fu + ∑ -Huj bcj)/Huu
Eigen::Matrix<Scalar,n,1> x = bc;
x(u) = -f(u);
for(int i=0;i<k.size();i++){ if(i!=u){ x(u)-=bc(i)*H(i,u); } }
x(u) /= H(u,u);
return x;
}
// Alec: Is there a smart template way to do this?
// jdumas: I guess you could do a templated for-loop starting from 16, and
// dispatching to the appropriate templated function when the argument matches
// (with a fallback to the dynamic version). Cf this example:
// https://gist.github.com/disconnect3d/13c2d035bb31b244df14
switch(kcount)
{
case 0: assert(false && "Handled above."); return Eigen::Matrix<Scalar,n,1>();
// % Matlibberish for generating these case statements:
// maxi=16;for i=1:maxi;fprintf(' case %d:\n {\n const bool D = (n-%d<=0)||(%d>=n)||(n>%d);\n return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:%d,Hpd>(H,f,k,bc);\n }\n',[i i i maxi i]);end
case 1:
{
const bool D = (n-1<=0)||(1>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:1,Hpd>(H,f,k,bc);
}
case 2:
{
const bool D = (n-2<=0)||(2>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:2,Hpd>(H,f,k,bc);
}
case 3:
{
const bool D = (n-3<=0)||(3>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:3,Hpd>(H,f,k,bc);
}
case 4:
{
const bool D = (n-4<=0)||(4>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:4,Hpd>(H,f,k,bc);
}
case 5:
{
const bool D = (n-5<=0)||(5>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:5,Hpd>(H,f,k,bc);
}
case 6:
{
const bool D = (n-6<=0)||(6>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:6,Hpd>(H,f,k,bc);
}
case 7:
{
const bool D = (n-7<=0)||(7>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:7,Hpd>(H,f,k,bc);
}
case 8:
{
const bool D = (n-8<=0)||(8>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:8,Hpd>(H,f,k,bc);
}
case 9:
{
const bool D = (n-9<=0)||(9>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:9,Hpd>(H,f,k,bc);
}
case 10:
{
const bool D = (n-10<=0)||(10>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:10,Hpd>(H,f,k,bc);
}
case 11:
{
const bool D = (n-11<=0)||(11>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:11,Hpd>(H,f,k,bc);
}
case 12:
{
const bool D = (n-12<=0)||(12>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:12,Hpd>(H,f,k,bc);
}
case 13:
{
const bool D = (n-13<=0)||(13>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:13,Hpd>(H,f,k,bc);
}
case 14:
{
const bool D = (n-14<=0)||(14>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:14,Hpd>(H,f,k,bc);
}
case 15:
{
const bool D = (n-15<=0)||(15>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:15,Hpd>(H,f,k,bc);
}
case 16:
{
const bool D = (n-16<=0)||(16>=n)||(n>16);
return min_quad_with_fixed<Scalar,D?Eigen::Dynamic:n,D?Eigen::Dynamic:16,Hpd>(H,f,k,bc);
}
default:
return min_quad_with_fixed<Scalar,Eigen::Dynamic,Eigen::Dynamic,Hpd>(H,f,k,bc);
}
}
template <typename Scalar, int n, int kcount, bool Hpd>
IGL_INLINE Eigen::Matrix<Scalar,n,1> igl::min_quad_with_fixed(
const Eigen::Matrix<Scalar,n,n> & H,
const Eigen::Matrix<Scalar,n,1> & f,
const Eigen::Array<bool,n,1> & k,
const Eigen::Matrix<Scalar,n,1> & bc)
{
// 0 and n should be handle outside this function
static_assert(kcount==Eigen::Dynamic || kcount>0 ,"");
static_assert(kcount==Eigen::Dynamic || kcount<n ,"");
const int ucount = n==Eigen::Dynamic ? Eigen::Dynamic : n-kcount;
static_assert(kcount==Eigen::Dynamic || ucount+kcount == n ,"");
static_assert((n==Eigen::Dynamic) == (ucount==Eigen::Dynamic),"");
static_assert((kcount==Eigen::Dynamic) == (ucount==Eigen::Dynamic),"");
assert((n==Eigen::Dynamic) || n == H.rows());
assert((kcount==Eigen::Dynamic) || kcount == k.count());
typedef Eigen::Matrix<Scalar,ucount,ucount> MatrixSuu;
typedef Eigen::Matrix<Scalar,ucount,kcount> MatrixSuk;
typedef Eigen::Matrix<Scalar,n,1> VectorSn;
typedef Eigen::Matrix<Scalar,ucount,1> VectorSu;
typedef Eigen::Matrix<Scalar,kcount,1> VectorSk;
const auto dyn_n = n==Eigen::Dynamic ? H.rows() : n;
const auto dyn_kcount = kcount==Eigen::Dynamic ? k.count() : kcount;
const auto dyn_ucount = ucount==Eigen::Dynamic ? dyn_n- dyn_kcount : ucount;
// For ucount==2 or kcount==2 this calls the coefficient initiliazer rather
// than the size initilizer, but I guess that's ok.
MatrixSuu Huu(dyn_ucount,dyn_ucount);
MatrixSuk Huk(dyn_ucount,dyn_kcount);
VectorSu mrhs(dyn_ucount);
VectorSk bck(dyn_kcount);
{
int ui = 0;
int ki = 0;
for(int i = 0;i<dyn_n;i++)
{
if(k(i))
{
bck(ki) = bc(i);
ki++;
}else
{
mrhs(ui) = f(i);
int uj = 0;
int kj = 0;
for(int j = 0;j<dyn_n;j++)
{
if(k(j))
{
Huk(ui,kj) = H(i,j);
kj++;
}else
{
Huu(ui,uj) = H(i,j);
uj++;
}
}
ui++;
}
}
}
mrhs += Huk * bck;
typedef typename
std::conditional<Hpd,
Eigen::LLT<MatrixSuu>,
// LDLT should be faster for indefinite problems but already found some
// cases where it was too inaccurate when called via quadprog_primal.
// Ideally this function takes LLT,LDLT, or
// CompleteOrthogonalDecomposition as a template parameter. "template
// template" parameters did work because LLT,LDLT have different number of
// template parameters from CompleteOrthogonalDecomposition. Perhaps
// there's a way to take advantage of LLT and LDLT's default template
// parameters (I couldn't figure out how).
Eigen::CompleteOrthogonalDecomposition<MatrixSuu>>::type
Solver;
VectorSu xu = Solver(Huu).solve(-mrhs);
VectorSn x(dyn_n);
{
int ui = 0;
int ki = 0;
for(int i = 0;i<dyn_n;i++)
{
if(k(i))
{
x(i) = bck(ki);
ki++;
}else
{
x(i) = xu(ui);
ui++;
}
}
}
return x;
}