Exemple #1
0
// Solves a pair of primal and dual LPs
//
//      minimize    c'*x
//      subject to  G*x + s = h
//                  A*x = b
//                  s >= 0
//
//      maximize    -h'*z - b'*y
//      subject to  G'*z + A'*y + c = 0
//                    z >= 0.
//
func Lp(c, G, h, A, b *matrix.FloatMatrix, solopts *SolverOptions,
	primalstart, dualstart *sets.FloatMatrixSet) (sol *Solution, err error) {

	if c == nil {
		err = errors.New("'c' must a column matrix")
		return
	}
	n := c.Rows()
	if n < 1 {
		err = errors.New("Number of variables must be at least 1")
		return
	}
	if G == nil || G.Cols() != n {
		err = errors.New(fmt.Sprintf("'G' must be matrix with %d columns", n))
		return
	}
	m := G.Rows()
	if h == nil || !h.SizeMatch(m, 1) {
		err = errors.New(fmt.Sprintf("'h' must be matrix of size (%d,1)", m))
		return
	}
	if A == nil {
		A = matrix.FloatZeros(0, n)
	}
	if A.Cols() != n {
		err = errors.New(fmt.Sprintf("'A' must be matrix with %d columns", n))
		return
	}
	p := A.Rows()
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if !b.SizeMatch(p, 1) {
		err = errors.New(fmt.Sprintf("'b' must be matrix of size (%d,1)", p))
		return
	}
	dims := sets.NewDimensionSet("l", "q", "s")
	dims.Set("l", []int{m})

	return ConeLp(c, G, h, A, b, dims, solopts, primalstart, dualstart)
}
Exemple #2
0
//
// Solves a geometric program
//
//   minimize    log sum exp (F0*x+g0)
//   subject to  log sum exp (Fi*x+gi) <= 0,  i=1,...,m
//               G*x <= h      
//               A*x = b
//
func Gp(K []int, F, g, G, h, A, b *matrix.FloatMatrix, solopts *SolverOptions) (sol *Solution, err error) {

    if err = checkArgK(K); err != nil {
        return
    }
    l := sumdim(K)

    if F == nil || F.Rows() != l {
        err = errors.New(fmt.Sprintf("'F' must matrix with %d rows", l))
        return
    }

    if g == nil || !g.SizeMatch(l, 1) {
        err = errors.New(fmt.Sprintf("'g' must matrix with size (%d,1)", l))
        return
    }
    n := F.Cols()

    if G == nil {
        G = matrix.FloatZeros(0, n)
    }
    if h == nil {
        h = matrix.FloatZeros(0, 1)
    }
    if G.Cols() != n {
        err = errors.New(fmt.Sprintf("'G' must matrix with size %d columns", n))
        return
    }
    ml := G.Rows()
    if h == nil || !h.SizeMatch(ml, 1) {
        err = errors.New(fmt.Sprintf("'h' must matrix with size (%d,1)", ml))
        return
    }

    if A == nil {
        A = matrix.FloatZeros(0, n)
    }
    if b == nil {
        b = matrix.FloatZeros(0, 1)
    }
    if A.Cols() != n {
        err = errors.New(fmt.Sprintf("'A' must matrix with size %d columns", n))
        return
    }
    p := A.Rows()
    if b == nil || !b.SizeMatch(p, 1) {
        err = errors.New(fmt.Sprintf("'b' must matrix with size (%d,1)", p))
        return
    }

    dims := sets.NewDimensionSet("l", "q", "s")
    dims.Set("l", []int{ml})
    gpProg := createGpProg(K, F, g)

    return Cp(gpProg, G, h, A, b, dims, solopts)
}
Exemple #3
0
// Solves a pair of primal and dual SDPs
//
//        minimize    c'*x
//        subject to  Gl*x + sl = hl
//                    mat(Gs[k]*x) + ss[k] = hs[k], k = 0, ..., N-1
//                    A*x = b
//                    sl >= 0,  ss[k] >= 0, k = 0, ..., N-1
//
//        maximize    -hl'*z - sum_k trace(hs[k]*zs[k]) - b'*y
//        subject to  Gl'*zl + sum_k Gs[k]'*vec(zs[k]) + A'*y + c = 0
//                    zl >= 0,  zs[k] >= 0, k = 0, ..., N-1.
//
// The inequalities sl >= 0 and zl >= 0 are elementwise vector
// inequalities.  The inequalities ss[k] >= 0, zs[k] >= 0 are matrix
// inequalities, i.e., the symmetric matrices ss[k] and zs[k] must be
// positive semidefinite.  mat(Gs[k]*x) is the symmetric matrix X with
// X[:] = Gs[k]*x.  For a symmetric matrix, zs[k], vec(zs[k]) is the
// vector zs[k][:].
//
func Sdp(c, Gl, hl, A, b *matrix.FloatMatrix, Ghs *sets.FloatMatrixSet, solopts *SolverOptions,
	primalstart, dualstart *sets.FloatMatrixSet) (sol *Solution, err error) {
	if c == nil {
		err = errors.New("'c' must a column matrix")
		return
	}
	n := c.Rows()
	if n < 1 {
		err = errors.New("Number of variables must be at least 1")
		return
	}
	if Gl == nil {
		Gl = matrix.FloatZeros(0, n)
	}
	if Gl.Cols() != n {
		err = errors.New(fmt.Sprintf("'G' must be matrix with %d columns", n))
		return
	}
	ml := Gl.Rows()
	if hl == nil {
		hl = matrix.FloatZeros(0, 1)
	}
	if !hl.SizeMatch(ml, 1) {
		err = errors.New(fmt.Sprintf("'hl' must be matrix of size (%d,1)", ml))
		return
	}
	Gsset := Ghs.At("Gs")
	ms := make([]int, 0)
	for i, Gs := range Gsset {
		if Gs.Cols() != n {
			err = errors.New(fmt.Sprintf("'Gs' must be list of matrices with %d columns", n))
			return
		}
		sz := int(math.Sqrt(float64(Gs.Rows())))
		if Gs.Rows() != sz*sz {
			err = errors.New(fmt.Sprintf("the squareroot of the number of rows of 'Gq[%d]' is not an integer", i))
			return
		}
		ms = append(ms, sz)
	}

	hsset := Ghs.At("hs")
	if len(Gsset) != len(hsset) {
		err = errors.New(fmt.Sprintf("'hs' must be a list of %d matrices", len(Gsset)))
		return
	}
	for i, hs := range hsset {
		if !hs.SizeMatch(ms[i], ms[i]) {
			s := fmt.Sprintf("hq[%d] has size (%d,%d). Expected size is (%d,%d)",
				i, hs.Rows(), hs.Cols(), ms[i], ms[i])
			err = errors.New(s)
			return
		}
	}
	if A == nil {
		A = matrix.FloatZeros(0, n)
	}
	if A.Cols() != n {
		err = errors.New(fmt.Sprintf("'A' must be matrix with %d columns", n))
		return
	}
	p := A.Rows()
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if !b.SizeMatch(p, 1) {
		err = errors.New(fmt.Sprintf("'b' must be matrix of size (%d,1)", p))
		return
	}
	dims := sets.NewDimensionSet("l", "q", "s")
	dims.Set("l", []int{ml})
	dims.Set("s", ms)
	N := dims.Sum("l") + dims.SumSquared("s")

	// Map hs matrices to h vector
	h := matrix.FloatZeros(N, 1)
	h.SetIndexesFromArray(hl.FloatArray()[:ml], matrix.MakeIndexSet(0, ml, 1)...)
	ind := ml
	for k, hs := range hsset {
		h.SetIndexesFromArray(hs.FloatArray(), matrix.MakeIndexSet(ind, ind+ms[k]*ms[k], 1)...)
		ind += ms[k] * ms[k]
	}

	Gargs := make([]*matrix.FloatMatrix, 0)
	Gargs = append(Gargs, Gl)
	Gargs = append(Gargs, Gsset...)
	G, sizeg := matrix.FloatMatrixStacked(matrix.StackDown, Gargs...)

	var pstart, dstart *sets.FloatMatrixSet = nil, nil
	if primalstart != nil {
		pstart = sets.NewFloatSet("x", "s")
		pstart.Set("x", primalstart.At("x")[0])
		slset := primalstart.At("sl")
		margs := make([]*matrix.FloatMatrix, 0, len(slset)+1)
		margs = append(margs, primalstart.At("s")[0])
		margs = append(margs, slset...)
		sl, _ := matrix.FloatMatrixStacked(matrix.StackDown, margs...)
		pstart.Set("s", sl)
	}

	if dualstart != nil {
		dstart = sets.NewFloatSet("y", "z")
		dstart.Set("y", dualstart.At("y")[0])
		zlset := primalstart.At("zl")
		margs := make([]*matrix.FloatMatrix, 0, len(zlset)+1)
		margs = append(margs, dualstart.At("z")[0])
		margs = append(margs, zlset...)
		zl, _ := matrix.FloatMatrixStacked(matrix.StackDown, margs...)
		dstart.Set("z", zl)
	}

	//fmt.Printf("h=\n%v\n", h.ToString("%.3f"))
	//fmt.Printf("G=\n%v\n", G.ToString("%.3f"))

	sol, err = ConeLp(c, G, h, A, b, dims, solopts, pstart, dstart)
	// unpack sol.Result
	if err == nil {
		s := sol.Result.At("s")[0]
		sl := matrix.FloatVector(s.FloatArray()[:ml])
		sol.Result.Append("sl", sl)
		ind := ml
		for _, m := range ms {
			sk := matrix.FloatNew(m, m, s.FloatArray()[ind:ind+m*m])
			sol.Result.Append("ss", sk)
			ind += m * m
		}

		z := sol.Result.At("z")[0]
		zl := matrix.FloatVector(s.FloatArray()[:ml])
		sol.Result.Append("zl", zl)
		ind = ml
		for i, k := range sizeg[1:] {
			zk := matrix.FloatNew(ms[i], ms[i], z.FloatArray()[ind:ind+k])
			sol.Result.Append("zs", zk)
			ind += k
		}
	}
	sol.Result.Remove("s")
	sol.Result.Remove("z")

	return

}
Exemple #4
0
// Solves a pair of primal and dual SOCPs
//
//     minimize    c'*x
//     subject to  Gl*x + sl = hl
//                 Gq[k]*x + sq[k] = hq[k],  k = 0, ..., N-1
//                 A*x = b
//                 sl >= 0,
//                 sq[k] >= 0, k = 0, ..., N-1
//
//     maximize   -hl'*z - sum_k hq[k]'*zq[k] - b'*y
//     subject to  Gl'*zl + sum_k Gq[k]'*zq[k] + A'*y + c = 0
//                 zl >= 0,  zq[k] >= 0, k = 0, ..., N-1.
//
// The inequalities sl >= 0 and zl >= 0 are elementwise vector
// inequalities.  The inequalities sq[k] >= 0, zq[k] >= 0 are second
// order cone inequalities, i.e., equivalent to
//
//     sq[k][0] >= || sq[k][1:] ||_2,  zq[k][0] >= || zq[k][1:] ||_2.
//
func Socp(c, Gl, hl, A, b *matrix.FloatMatrix, Ghq *sets.FloatMatrixSet, solopts *SolverOptions,
	primalstart, dualstart *sets.FloatMatrixSet) (sol *Solution, err error) {
	if c == nil {
		err = errors.New("'c' must a column matrix")
		return
	}
	n := c.Rows()
	if n < 1 {
		err = errors.New("Number of variables must be at least 1")
		return
	}
	if Gl == nil {
		Gl = matrix.FloatZeros(0, n)
	}
	if Gl.Cols() != n {
		err = errors.New(fmt.Sprintf("'G' must be matrix with %d columns", n))
		return
	}
	ml := Gl.Rows()
	if hl == nil {
		hl = matrix.FloatZeros(0, 1)
	}
	if !hl.SizeMatch(ml, 1) {
		err = errors.New(fmt.Sprintf("'hl' must be matrix of size (%d,1)", ml))
		return
	}
	Gqset := Ghq.At("Gq")
	mq := make([]int, 0)
	for i, Gq := range Gqset {
		if Gq.Cols() != n {
			err = errors.New(fmt.Sprintf("'Gq' must be list of matrices with %d columns", n))
			return
		}
		if Gq.Rows() == 0 {
			err = errors.New(fmt.Sprintf("the number of rows of 'Gq[%d]' is zero", i))
			return
		}
		mq = append(mq, Gq.Rows())
	}
	hqset := Ghq.At("hq")
	if len(Gqset) != len(hqset) {
		err = errors.New(fmt.Sprintf("'hq' must be a list of %d matrices", len(Gqset)))
		return
	}
	for i, hq := range hqset {
		if !hq.SizeMatch(Gqset[i].Rows(), 1) {
			s := fmt.Sprintf("hq[%d] has size (%d,%d). Expected size is (%d,1)",
				i, hq.Rows(), hq.Cols(), Gqset[i].Rows())
			err = errors.New(s)
			return
		}
	}
	if A == nil {
		A = matrix.FloatZeros(0, n)
	}
	if A.Cols() != n {
		err = errors.New(fmt.Sprintf("'A' must be matrix with %d columns", n))
		return
	}
	p := A.Rows()
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if !b.SizeMatch(p, 1) {
		err = errors.New(fmt.Sprintf("'b' must be matrix of size (%d,1)", p))
		return
	}
	dims := sets.NewDimensionSet("l", "q", "s")
	dims.Set("l", []int{ml})
	dims.Set("q", mq)
	//N := dims.Sum("l", "q")

	hargs := make([]*matrix.FloatMatrix, 0, len(hqset)+1)
	hargs = append(hargs, hl)
	hargs = append(hargs, hqset...)
	h, indh := matrix.FloatMatrixStacked(matrix.StackDown, hargs...)

	Gargs := make([]*matrix.FloatMatrix, 0, len(Gqset)+1)
	Gargs = append(Gargs, Gl)
	Gargs = append(Gargs, Gqset...)
	G, indg := matrix.FloatMatrixStacked(matrix.StackDown, Gargs...)

	var pstart, dstart *sets.FloatMatrixSet = nil, nil
	if primalstart != nil {
		pstart = sets.NewFloatSet("x", "s")
		pstart.Set("x", primalstart.At("x")[0])
		slset := primalstart.At("sl")
		margs := make([]*matrix.FloatMatrix, 0, len(slset)+1)
		margs = append(margs, primalstart.At("s")[0])
		margs = append(margs, slset...)
		sl, _ := matrix.FloatMatrixStacked(matrix.StackDown, margs...)
		pstart.Set("s", sl)
	}

	if dualstart != nil {
		dstart = sets.NewFloatSet("y", "z")
		dstart.Set("y", dualstart.At("y")[0])
		zlset := primalstart.At("zl")
		margs := make([]*matrix.FloatMatrix, 0, len(zlset)+1)
		margs = append(margs, dualstart.At("z")[0])
		margs = append(margs, zlset...)
		zl, _ := matrix.FloatMatrixStacked(matrix.StackDown, margs...)
		dstart.Set("z", zl)
	}

	sol, err = ConeLp(c, G, h, A, b, dims, solopts, pstart, dstart)
	// unpack sol.Result
	if err == nil {
		s := sol.Result.At("s")[0]
		sl := matrix.FloatVector(s.FloatArray()[:ml])
		sol.Result.Append("sl", sl)
		ind := ml
		for _, k := range indh[1:] {
			sk := matrix.FloatVector(s.FloatArray()[ind : ind+k])
			sol.Result.Append("sq", sk)
			ind += k
		}

		z := sol.Result.At("z")[0]
		zl := matrix.FloatVector(z.FloatArray()[:ml])
		sol.Result.Append("zl", zl)
		ind = ml
		for _, k := range indg[1:] {
			zk := matrix.FloatVector(z.FloatArray()[ind : ind+k])
			sol.Result.Append("zq", zk)
			ind += k
		}
	}
	sol.Result.Remove("s")
	sol.Result.Remove("z")

	return
}
Exemple #5
0
// Solves a convex optimization problem with a linear objective
//
//        minimize    c'*x
//        subject to  f(x) <= 0
//                    G*x <= h
//                    A*x = b.
//
// f is vector valued, convex and twice differentiable.  The linear
// inequalities are with respect to a cone C defined as the Cartesian
// product of N + M + 1 cones:
//
//        C = C_0 x C_1 x .... x C_N x C_{N+1} x ... x C_{N+M}.
//
// The first cone C_0 is the nonnegative orthant of dimension ml.  The
// next N cones are second order cones of dimension r[0], ..., r[N-1].
// The second order cone of dimension m is defined as
//
//        { (u0, u1) in R x R^{m-1} | u0 >= ||u1||_2 }.
//
// The next M cones are positive semidefinite cones of order t[0], ..., t[M-1] >= 0.
//
// The structure of C is specified by DimensionSet dims which holds following sets
//
//   dims.At("l")  l, the dimension of the nonnegative orthant (array of length 1)
//   dims.At("q")  r[0], ... r[N-1], list with the dimesions of the second-order cones
//   dims.At("s")  t[0], ... t[M-1], array with the dimensions of the positive
//                 semidefinite cones
//
// The default value for dims is l: []int{h.Rows()}, q: []int{}, s: []int{}.
//
// On exit Solution contains the result and information about the accurancy of the
// solution. if SolutionStatus is Optimal then Solution.Result contains solutions
// for the problems.
//
//   Result.At("x")[0]    primal solution
//   Result.At("snl")[0]  non-linear constraint slacks
//   Result.At("sl")[0]   linear constraint slacks
//   Result.At("y")[0]    values for linear equality constraints y
//   Result.At("znl")[0]  values of dual variables for nonlinear inequalities
//   Result.At("zl")[0]   values of dual variables for linear inequalities
//
// If err is non-nil then sol is nil and err contains information about the argument or
// computation error.
//
func Cpl(F ConvexProg, c, G, h, A, b *matrix.FloatMatrix, dims *sets.DimensionSet, solopts *SolverOptions) (sol *Solution, err error) {

	var mnl int
	var x0 *matrix.FloatMatrix

	mnl, x0, err = F.F0()
	if err != nil {
		return
	}

	if x0.Cols() != 1 {
		err = errors.New("'x0' must be matrix with one column")
		return
	}
	if c == nil {
		err = errors.New("'c' must be non nil matrix")
		return
	}
	if !c.SizeMatch(x0.Size()) {
		err = errors.New(fmt.Sprintf("'c' must be matrix of size (%d,1)", x0.Rows()))
		return
	}

	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() > 1 {
		err = errors.New("'h' must be matrix with 1 column")
		return
	}

	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}

	cdim := dims.Sum("l", "q") + dims.SumSquared("s")
	//cdim_pckd := dims.Sum("l", "q") + dims.SumPacked("s")
	//cdim_diag := dims.Sum("l", "q", "s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	if G == nil {
		G = matrix.FloatZeros(0, c.Rows())
	}
	if !G.SizeMatch(cdim, c.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, c.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, c.Rows())
	}
	if A.Cols() != c.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", c.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	var mc = matrixVar{c}
	var mb = matrixVar{b}
	var mA = matrixVarA{A}
	var mG = matrixVarG{G, dims}

	solvername := solopts.KKTSolverName
	if len(solvername) == 0 {
		if len(dims.At("q")) > 0 || len(dims.At("s")) > 0 {
			solvername = "chol"
		} else {
			solvername = "chol2"
		}
	}

	var factor kktFactor
	var kktsolver KKTCpSolver = nil
	if kktfunc, ok := solvers[solvername]; ok {
		// kkt function returns us problem spesific factor function.
		factor, err = kktfunc(G, dims, A, mnl)
		// solver is
		kktsolver = func(W *sets.FloatMatrixSet, x, z *matrix.FloatMatrix) (KKTFunc, error) {
			_, Df, H, err := F.F2(x, z)
			if err != nil {
				return nil, err
			}
			return factor(W, H, Df)
		}
	} else {
		err = errors.New(fmt.Sprintf("solver '%s' not known", solvername))
		return
	}

	//return CplCustom(F, c, &mG, h, &mA, b, dims, kktsolver, solopts)
	return cpl_problem(F, &mc, &mG, h, &mA, &mb, dims, kktsolver, solopts, x0, mnl)
}
Exemple #6
0
// Solves a convex optimization problem with a linear objective
//
//        minimize    c'*x
//        subject to  f(x) <= 0
//                    G*x <= h
//                    A*x = b.
//
// using custom KTT equation solver and custom constraints G and A.
//
func CplCustomMatrix(F ConvexProg, c *matrix.FloatMatrix, G MatrixG, h *matrix.FloatMatrix,
	A MatrixA, b *matrix.FloatMatrix, dims *sets.DimensionSet, kktsolver KKTCpSolver,
	solopts *SolverOptions) (sol *Solution, err error) {

	var mnl int
	var x0 *matrix.FloatMatrix

	mnl, x0, err = F.F0()
	if err != nil {
		return
	}

	if x0.Cols() != 1 {
		err = errors.New("'x0' must be matrix with one column")
		return
	}
	if c == nil {
		err = errors.New("'c' must be non nil matrix")
		return
	}
	if !c.SizeMatch(x0.Size()) {
		err = errors.New(fmt.Sprintf("'c' must be matrix of size (%d,1)", x0.Rows()))
		return
	}

	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() > 1 {
		err = errors.New("'h' must be matrix with 1 column")
		return
	}

	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}

	cdim := dims.Sum("l", "q") + dims.SumSquared("s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}

	mc := matrixVar{c}
	mb := matrixVar{b}
	var mG MatrixVarG
	var mA MatrixVarA

	if G == nil {
		mG = &matrixVarG{matrix.FloatZeros(0, c.Rows()), dims}
	} else {
		mG = &matrixIfG{G}
	}
	if A == nil {
		mA = &matrixVarA{matrix.FloatZeros(0, c.Rows())}
	} else {
		mA = &matrixIfA{A}
	}

	return cpl_problem(F, &mc, mG, h, mA, &mb, dims, kktsolver, solopts, x0, mnl)
}
Exemple #7
0
// Solves a convex optimization problem with a linear objective
//
//        minimize    c'*x
//        subject to  f(x) <= 0
//                    G*x <= h
//                    A*x = b.
//
// using custom KTT equation solver.
//
func CplCustomKKT(F ConvexProg, c *matrix.FloatMatrix, G, h, A, b *matrix.FloatMatrix,
	dims *sets.DimensionSet, kktsolver KKTCpSolver,
	solopts *SolverOptions) (sol *Solution, err error) {

	var mnl int
	var x0 *matrix.FloatMatrix

	mnl, x0, err = F.F0()
	if err != nil {
		return
	}

	if x0.Cols() != 1 {
		err = errors.New("'x0' must be matrix with one column")
		return
	}
	if c == nil {
		err = errors.New("'c' must be non nil matrix")
		return
	}
	if !c.SizeMatch(x0.Size()) {
		err = errors.New(fmt.Sprintf("'c' must be matrix of size (%d,1)", x0.Rows()))
		return
	}

	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() > 1 {
		err = errors.New("'h' must be matrix with 1 column")
		return
	}

	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}

	cdim := dims.Sum("l", "q") + dims.SumSquared("s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	if G == nil {
		G = matrix.FloatZeros(0, c.Rows())
	}
	if !G.SizeMatch(cdim, c.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, c.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, c.Rows())
	}
	if A.Cols() != c.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", c.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	var mc = matrixVar{c}
	var mb = matrixVar{b}
	var mA = matrixVarA{A}
	var mG = matrixVarG{G, dims}

	return cpl_problem(F, &mc, &mG, h, &mA, &mb, dims, kktsolver, solopts, x0, mnl)
}
Exemple #8
0
// Solves a pair of primal and dual convex quadratic cone programs
//
//        minimize    (1/2)*x'*P*x + q'*x
//        subject to  G*x + s = h
//                    A*x = b
//                    s >= 0
//
//        maximize    -(1/2)*(q + G'*z + A'*y)' * pinv(P) * (q + G'*z + A'*y)
//                    - h'*z - b'*y
//        subject to  q + G'*z + A'*y in range(P)
//                    z >= 0.
//
// The inequalities are with respect to a cone C defined as the Cartesian
// product of N + M + 1 cones:
//
//        C = C_0 x C_1 x .... x C_N x C_{N+1} x ... x C_{N+M}.
//
// The first cone C_0 is the nonnegative orthant of dimension ml.
// The next N cones are 2nd order cones of dimension r[0], ..., r[N-1].
// The second order cone of dimension m is defined as
//
//        { (u0, u1) in R x R^{m-1} | u0 >= ||u1||_2 }.
//
// The next M cones are positive semidefinite cones of order t[0], ..., t[M-1] >= 0.
//
// The structure of C is specified by DimensionSet dims which holds following sets
//
//   dims.At("l")  l, the dimension of the nonnegative orthant (array of length 1)
//   dims.At("q")  r[0], ... r[N-1], list with the dimesions of the second-order cones
//   dims.At("s")  t[0], ... t[M-1], array with the dimensions of the positive
//                 semidefinite cones
//
// The default value for dims is l: []int{G.Rows()}, q: []int{}, s: []int{}.
//
// Argument initval contains optional starting points for primal and
// dual problems. If non-nil then initval is a FloatMatrixSet having following entries.
//
//  initvals.At("x")[0]  starting point for x
//  initvals.At("s")[0]  starting point for s
//  initvals.At("y")[0]  starting point for y
//  initvals.At("z")[0]  starting point for z
//
// On exit Solution contains the result and information about the accurancy of the
// solution. if SolutionStatus is Optimal then Solution.Result contains solutions
// for the problems.
//
//   Result.At("x")[0]  solution for x
//   Result.At("y")[0]  solution for y
//   Result.At("s")[0]  solution for s
//   Result.At("z")[0]  solution for z
//
func ConeQp(P, q, G, h, A, b *matrix.FloatMatrix, dims *sets.DimensionSet, solopts *SolverOptions,
	initvals *sets.FloatMatrixSet) (sol *Solution, err error) {

	if q == nil || q.Cols() != 1 {
		err = errors.New("'q' must be non-nil matrix with one column")
		return
	}
	if P == nil || P.Rows() != q.Rows() || P.Cols() != q.Rows() {
		err = errors.New(fmt.Sprintf("'P' must be non-nil matrix of size (%d, %d)",
			q.Rows(), q.Rows()))
		return
	}

	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() != 1 {
		err = errors.New("'h' must be non-nil matrix with one column")
		return
	}
	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}

	err = checkConeQpDimensions(dims)
	if err != nil {
		return
	}

	cdim := dims.Sum("l", "q") + dims.SumSquared("s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	if G == nil {
		G = matrix.FloatZeros(0, q.Rows())
	}
	if !G.SizeMatch(cdim, q.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, q.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, q.Rows())
	}
	if A.Cols() != q.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", q.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	solvername := solopts.KKTSolverName
	if len(solvername) == 0 {
		if len(dims.At("q")) > 0 || len(dims.At("s")) > 0 {
			solvername = "ldl"
		} else {
			solvername = "chol2"
		}
	}

	var factor kktFactor
	var kktsolver KKTConeSolver = nil
	if kktfunc, ok := solvers[solvername]; ok {
		// kkt function returns us problem spesific factor function.
		factor, err = kktfunc(G, dims, A, 0)
		if err != nil {
			return nil, err
		}
		kktsolver = func(W *sets.FloatMatrixSet) (KKTFunc, error) {
			return factor(W, P, nil)
		}
	} else {
		err = errors.New(fmt.Sprintf("solver '%s' not known", solvername))
		return
	}

	mA := &matrixVarA{A}
	mG := &matrixVarG{G, dims}
	mP := &matrixVarP{P}
	mq := &matrixVar{q}
	mb := &matrixVar{b}

	return coneqp_problem(mP, mq, mG, h, mA, mb, dims, kktsolver, solopts, initvals)
}
Exemple #9
0
// Solves a pair of primal and dual convex quadratic cone programs using custom KKT solver.
//
func ConeQpCustomKKT(P, q, G, h, A, b *matrix.FloatMatrix, dims *sets.DimensionSet, kktsolver KKTConeSolver,
	solopts *SolverOptions, initvals *sets.FloatMatrixSet) (sol *Solution, err error) {

	if q == nil || q.Cols() != 1 {
		err = errors.New("'q' must be non-nil matrix with one column")
		return
	}
	if P == nil || P.Rows() != q.Rows() || P.Cols() != q.Rows() {
		err = errors.New(fmt.Sprintf("'P' must be non-nil matrix of size (%d, %d)",
			q.Rows(), q.Rows()))
		return
	}

	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() != 1 {
		err = errors.New("'h' must be non-nil matrix with one column")
		return
	}
	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}

	err = checkConeQpDimensions(dims)
	if err != nil {
		return
	}

	cdim := dims.Sum("l", "q") + dims.SumSquared("s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	if G == nil {
		G = matrix.FloatZeros(0, q.Rows())
	}
	if !G.SizeMatch(cdim, q.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, q.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, q.Rows())
	}
	if A.Cols() != q.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", q.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	if kktsolver == nil {
		err = errors.New("nil kktsolver not allowed")
		return
	}

	mA := &matrixVarA{A}
	mG := &matrixVarG{G, dims}
	mP := &matrixVarP{P}
	mq := &matrixVar{q}
	mb := &matrixVar{b}

	return coneqp_problem(mP, mq, mG, h, mA, mb, dims, kktsolver, solopts, initvals)
}
Exemple #10
0
// Solves a pair of primal and dual cone programs  using custom KKT solver.
//
func ConeLpCustomKKT(c, G, h, A, b *matrix.FloatMatrix, dims *sets.DimensionSet,
	kktsolver KKTConeSolver, solopts *SolverOptions, primalstart,
	dualstart *sets.FloatMatrixSet) (sol *Solution, err error) {

	if c == nil || c.Cols() > 1 {
		err = errors.New("'c' must be matrix with 1 column")
		return
	}
	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() > 1 {
		err = errors.New("'h' must be matrix with 1 column")
		return
	}

	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}
	cdim := dims.Sum("l", "q") + dims.SumSquared("s")
	cdim_pckd := dims.Sum("l", "q") + dims.SumPacked("s")
	//cdim_diag := dims.Sum("l", "q", "s")

	if G == nil {
		G = matrix.FloatZeros(0, c.Rows())
	}
	if !G.SizeMatch(cdim, c.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, c.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, c.Rows())
	}
	if A.Cols() != c.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", c.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	if b.Rows() > c.Rows() || b.Rows()+cdim_pckd < c.Rows() {
		err = errors.New("Rank(A) < p or Rank([G; A]) < n")
		return
	}

	mA := &matrixVarA{A}
	mG := &matrixVarG{G, dims}
	mc := &matrixVar{c}
	mb := &matrixVar{b}

	return conelp_problem(mc, mG, h, mA, mb, dims, kktsolver, solopts, primalstart, dualstart)
}
Exemple #11
0
// Solves a pair of primal and dual cone programs
//
//        minimize    c'*x
//        subject to  G*x + s = h
//                    A*x = b
//                    s >= 0
//
//        maximize    -h'*z - b'*y
//        subject to  G'*z + A'*y + c = 0
//                    z >= 0.
//
// The inequalities are with respect to a cone C defined as the Cartesian
// product of N + M + 1 cones:
//
//        C = C_0 x C_1 x .... x C_N x C_{N+1} x ... x C_{N+M}.
//
// The first cone C_0 is the nonnegative orthant of dimension ml.
// The next N cones are second order cones of dimension r[0], ..., r[N-1].
// The second order cone of dimension m is defined as
//
//        { (u0, u1) in R x R^{m-1} | u0 >= ||u1||_2 }.
//
// The next M cones are positive semidefinite cones of order t[0], ..., t[M-1] >= 0.
//
// The structure of C is specified by DimensionSet dims which holds following sets
//
//   dims.At("l")  l, the dimension of the nonnegative orthant (array of length 1)
//   dims.At("q")  r[0], ... r[N-1], list with the dimesions of the second-order cones
//   dims.At("s")  t[0], ... t[M-1], array with the dimensions of the positive
//                 semidefinite cones
//
// The default value for dims is l: []int{G.Rows()}, q: []int{}, s: []int{}.
//
// Arguments primalstart, dualstart are optional starting points for primal and
// dual problems. If non-nil then primalstart is a FloatMatrixSet having two entries.
//
//  primalstart.At("x")[0]  starting point for x
//  primalstart.At("s")[0]  starting point for s
//  dualstart.At("y")[0]    starting point for y
//  dualstart.At("z")[0]    starting point for z
//
// On exit Solution contains the result and information about the accurancy of the
// solution. if SolutionStatus is Optimal then Solution.Result contains solutions
// for the problems.
//
//   Result.At("x")[0]  solution for x
//   Result.At("y")[0]  solution for y
//   Result.At("s")[0]  solution for s
//   Result.At("z")[0]  solution for z
//
func ConeLp(c, G, h, A, b *matrix.FloatMatrix, dims *sets.DimensionSet, solopts *SolverOptions,
	primalstart, dualstart *sets.FloatMatrixSet) (sol *Solution, err error) {

	if c == nil || c.Cols() > 1 {
		err = errors.New("'c' must be matrix with 1 column")
		return
	}
	if c.Rows() < 1 {
		err = errors.New("No variables, 'c' must have at least one row")
		return

	}
	if h == nil || h.Cols() > 1 {
		err = errors.New("'h' must be matrix with 1 column")
		return
	}

	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}

	cdim := dims.Sum("l", "q") + dims.SumSquared("s")
	cdim_pckd := dims.Sum("l", "q") + dims.SumPacked("s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	if G == nil {
		G = matrix.FloatZeros(0, c.Rows())
	}
	if !G.SizeMatch(cdim, c.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, c.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, c.Rows())
	}
	if A.Cols() != c.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", c.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	if b.Rows() > c.Rows() || b.Rows()+cdim_pckd < c.Rows() {
		err = errors.New("Rank(A) < p or Rank([G; A]) < n")
		return
	}

	solvername := solopts.KKTSolverName
	if len(solvername) == 0 {
		if len(dims.At("q")) > 0 || len(dims.At("s")) > 0 {
			solvername = "qr"
		} else {
			solvername = "chol2"
		}
	}

	var factor kktFactor
	var kktsolver KKTConeSolver = nil
	if kktfunc, ok := lpsolvers[solvername]; ok {
		// kkt function returns us problem spesific factor function.
		factor, err = kktfunc(G, dims, A, 0)
		if err != nil {
			return nil, err
		}
		kktsolver = func(W *sets.FloatMatrixSet) (KKTFunc, error) {
			return factor(W, nil, nil)
		}
	} else {
		err = errors.New(fmt.Sprintf("solver '%s' not known", solvername))
		return
	}
	//return ConeLpCustom(c, &mG, h, &mA, b, dims, kktsolver, solopts, primalstart, dualstart)
	c_e := &matrixVar{c}
	G_e := &matrixVarG{G, dims}
	A_e := &matrixVarA{A}
	b_e := &matrixVar{b}
	return conelp_problem(c_e, G_e, h, A_e, b_e, dims, kktsolver, solopts, primalstart, dualstart)
}
Exemple #12
0
// Solves a convex optimization problem with a linear objective
//
//       minimize    f0(x)
//       subject to  fk(x) <= 0, k = 1, ..., mnl
//                   G*x   <= h
//                   A*x    = b.
//
// using custom solver for KKT equations.
//
func CpCustomKKT(F ConvexProg, G, h, A, b *matrix.FloatMatrix, dims *sets.DimensionSet,
	kktsolver KKTCpSolver, solopts *SolverOptions) (sol *Solution, err error) {

	var mnl int
	var x0 *matrix.FloatMatrix

	mnl, x0, err = F.F0()
	if err != nil {
		return
	}

	if x0.Cols() != 1 {
		err = errors.New("'x0' must be matrix with one column")
		return
	}
	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() > 1 {
		err = errors.New("'h' must be matrix with 1 column")
		return
	}

	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}
	if err = checkConeLpDimensions(dims); err != nil {
		return
	}
	cdim := dims.Sum("l", "q") + dims.SumSquared("s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	if G == nil {
		G = matrix.FloatZeros(0, x0.Rows())
	}
	if !G.SizeMatch(cdim, x0.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, x0.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, x0.Rows())
	}
	if A.Cols() != x0.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", x0.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	if kktsolver == nil {
		err = errors.New("'kktsolver' must be non-nil function.")
		return
	}

	c_e := newEpigraph(x0, 1.0)
	blas.ScalFloat(x0, 0.0)
	G_e := epMatrixG{G, dims}
	A_e := epMatrixA{A}
	b_e := matrixVar{b}

	return cp_problem(F, c_e, &G_e, h, &A_e, &b_e, dims, kktsolver, solopts, x0, mnl)
}
Exemple #13
0
// Solves a convex optimization problem with a linear objective
//
//       minimize    f0(x)
//       subject to  fk(x) <= 0, k = 1, ..., mnl
//                   G*x   <= h
//                   A*x    = b.
//
// f is vector valued, convex and twice differentiable.  The linear
// inequalities are with respect to a cone C defined as the Cartesian
// product of N + M + 1 cones:
//
//        C = C_0 x C_1 x .... x C_N x C_{N+1} x ... x C_{N+M}.
//
// The first cone C_0 is the nonnegative orthant of dimension ml.  The
// next N cones are second order cones of dimension r[0], ..., r[N-1].
// The second order cone of dimension m is defined as
//
//        { (u0, u1) in R x R^{m-1} | u0 >= ||u1||_2 }.
//
// The next M cones are positive semidefinite cones of order t[0], ..., t[M-1] >= 0.
//
// The structure of C is specified by DimensionSet dims which holds following sets
//
//   dims.At("l")  l, the dimension of the nonnegative orthant (array of length 1)
//   dims.At("q")  r[0], ... r[N-1], list with the dimesions of the second-order cones
//   dims.At("s")  t[0], ... t[M-1], array with the dimensions of the positive
//                 semidefinite cones
//
// The default value for dims is l: []int{h.Rows()}, q: []int{}, s: []int{}.
//
// On exit Solution contains the result and information about the accurancy of the
// solution. if SolutionStatus is Optimal then Solution.Result contains solutions
// for the problems.
//
//   Result.At("x")[0]    primal solution
//   Result.At("snl")[0]  non-linear constraint slacks
//   Result.At("sl")[0]   linear constraint slacks
//   Result.At("y")[0]    values for linear equality constraints y
//   Result.At("znl")[0]  values of dual variables for nonlinear inequalities
//   Result.At("zl")[0]   values of dual variables for linear inequalities
//
// If err is non-nil then sol is nil and err contains information about the argument or
// computation error.
//
func Cp(F ConvexProg, G, h, A, b *matrix.FloatMatrix, dims *sets.DimensionSet, solopts *SolverOptions) (sol *Solution, err error) {

	var mnl int
	var x0 *matrix.FloatMatrix

	mnl, x0, err = F.F0()
	if err != nil {
		return
	}

	if x0.Cols() != 1 {
		err = errors.New("'x0' must be matrix with one column")
		return
	}
	if h == nil {
		h = matrix.FloatZeros(0, 1)
	}
	if h.Cols() > 1 {
		err = errors.New("'h' must be matrix with 1 column")
		return
	}

	if dims == nil {
		dims = sets.NewDimensionSet("l", "q", "s")
		dims.Set("l", []int{h.Rows()})
	}
	if err = checkConeLpDimensions(dims); err != nil {
		return
	}
	cdim := dims.Sum("l", "q") + dims.SumSquared("s")

	if h.Rows() != cdim {
		err = errors.New(fmt.Sprintf("'h' must be float matrix of size (%d,1)", cdim))
		return
	}

	if G == nil {
		G = matrix.FloatZeros(0, x0.Rows())
	}
	if !G.SizeMatch(cdim, x0.Rows()) {
		estr := fmt.Sprintf("'G' must be of size (%d,%d)", cdim, x0.Rows())
		err = errors.New(estr)
		return
	}

	// Check A and set defaults if it is nil
	if A == nil {
		// zeros rows reduces Gemv to vector products
		A = matrix.FloatZeros(0, x0.Rows())
	}
	if A.Cols() != x0.Rows() {
		estr := fmt.Sprintf("'A' must have %d columns", x0.Rows())
		err = errors.New(estr)
		return
	}

	// Check b and set defaults if it is nil
	if b == nil {
		b = matrix.FloatZeros(0, 1)
	}
	if b.Cols() != 1 {
		estr := fmt.Sprintf("'b' must be a matrix with 1 column")
		err = errors.New(estr)
		return
	}
	if b.Rows() != A.Rows() {
		estr := fmt.Sprintf("'b' must have length %d", A.Rows())
		err = errors.New(estr)
		return
	}

	solvername := solopts.KKTSolverName
	if len(solvername) == 0 {
		if len(dims.At("q")) > 0 || len(dims.At("s")) > 0 {
			solvername = "chol"
		} else {
			solvername = "chol2"
		}
	}

	c_e := newEpigraph(x0, 1.0)
	blas.ScalFloat(c_e.m(), 0.0)
	//F_e := &cpProg{F}
	G_e := epMatrixG{G, dims}
	A_e := epMatrixA{A}
	b_e := matrixVar{b}

	var factor kktFactor
	var kktsolver KKTCpSolver = nil
	if kktfunc, ok := solvers[solvername]; ok {
		// kkt function returns us problem spesific factor function.
		factor, err = kktfunc(G, dims, A, mnl)
		if err != nil {
			return nil, err
		}
		// solver is
		kktsolver = func(W *sets.FloatMatrixSet, x, z *matrix.FloatMatrix) (KKTFunc, error) {
			_, Df, H, err := F.F2(x, z)
			if err != nil {
				return nil, err
			}
			return factor(W, H, Df.GetSubMatrix(1, 0))
		}
	} else {
		err = errors.New(fmt.Sprintf("solver '%s' not known", solvername))
		return
	}

	return cp_problem(F, c_e, &G_e, h, &A_e, &b_e, dims, kktsolver, solopts, x0, mnl)
}