diff --git a/MathLib/LinAlg/Eigen/EigenLinearSolver.cpp b/MathLib/LinAlg/Eigen/EigenLinearSolver.cpp
index 1f0c394355fe60bba38875674a9e2e4f6b07b775..2dca2852594c06020d50c4390a5820eb60c77710 100644
--- a/MathLib/LinAlg/Eigen/EigenLinearSolver.cpp
+++ b/MathLib/LinAlg/Eigen/EigenLinearSolver.cpp
@@ -388,6 +388,9 @@ std::unique_ptr<EigenLinearSolverBase> createIterativeSolver(
case EigenOption::PreconType::DIAGONAL:
return createIterativeSolver<
Solver, Eigen::DiagonalPreconditioner<double>>();
+ case EigenOption::PreconType::LeastSquareDIAGONAL:
+ return createIterativeSolver<
+ Solver, Eigen::LeastSquareDiagonalPreconditioner<double>>();
case EigenOption::PreconType::ILUT:
// TODO for this preconditioner further options can be passed.
// see
@@ -429,6 +432,11 @@ std::unique_ptr<EigenLinearSolverBase> createIterativeSolver(
{
return createIterativeSolver<EigenCGSolver>(precon_type);
}
+ case EigenOption::SolverType::LeastSquareCG:
+ {
+ return createIterativeSolver<Eigen::LeastSquaresConjugateGradient>(
+ precon_type);
+ }
case EigenOption::SolverType::GMRES:
{
#ifdef USE_EIGEN_UNSUPPORTED
@@ -488,6 +496,7 @@ EigenLinearSolver::EigenLinearSolver(std::string const& /*solver_name*/,
Eigen::SparseLU<Matrix, Eigen::COLAMDOrdering<int>>;
solver_ = std::make_unique<
details::EigenDirectLinearSolver<SolverType>>();
+ can_solve_rectangular_ = false;
return;
}
case EigenOption::SolverType::BiCGSTAB:
@@ -498,12 +507,19 @@ EigenLinearSolver::EigenLinearSolver(std::string const& /*solver_name*/,
case EigenOption::SolverType::IDRSTABL:
solver_ = details::createIterativeSolver(option_.solver_type,
option_.precon_type);
+ can_solve_rectangular_ = false;
+ return;
+ case EigenOption::SolverType::LeastSquareCG:
+ solver_ = details::createIterativeSolver(option_.solver_type,
+ option_.precon_type);
+ can_solve_rectangular_ = true;
return;
case EigenOption::SolverType::PardisoLU:
{
#ifdef USE_MKL
using SolverType = Eigen::PardisoLU<EigenMatrix::RawMatrixType>;
solver_.reset(new details::EigenDirectLinearSolver<SolverType>);
+ can_solve_rectangular_ = false;
return;
#else
OGS_FATAL(
diff --git a/MathLib/LinAlg/Eigen/EigenLinearSolver.h b/MathLib/LinAlg/Eigen/EigenLinearSolver.h
index 1955f1fd8495e3609af9556119b066bc3e725887..2f58fc83738f5137132abb4778f6b7cb7e615b19 100644
--- a/MathLib/LinAlg/Eigen/EigenLinearSolver.h
+++ b/MathLib/LinAlg/Eigen/EigenLinearSolver.h
@@ -71,9 +71,13 @@ public:
MathLib::LinearSolverBehaviour const linear_solver_behaviour =
MathLib::LinearSolverBehaviour::RECOMPUTE);
+ /// Get, if the solver can handle rectangular equation systems
+ bool canSolveRectangular() const { return can_solve_rectangular_; }
+
protected:
EigenOption option_;
std::unique_ptr<EigenLinearSolverBase> solver_;
+ bool can_solve_rectangular_ = false;
void setRestart();
void setL();
void setS();
diff --git a/MathLib/LinAlg/Eigen/EigenOption.cpp b/MathLib/LinAlg/Eigen/EigenOption.cpp
index b9df0ff226ace71eb98ea7d1eb4a5b82b7092eaa..07b11082bffb88ec04189ebedbc4577f79d287c1 100644
--- a/MathLib/LinAlg/Eigen/EigenOption.cpp
+++ b/MathLib/LinAlg/Eigen/EigenOption.cpp
@@ -38,6 +38,10 @@ EigenOption::SolverType EigenOption::getSolverType(
{
return SolverType::CG;
}
+ if (solver_name == "LeastSquareCG")
+ {
+ return SolverType::LeastSquareCG;
+ }
if (solver_name == "BiCGSTAB")
{
return SolverType::BiCGSTAB;
@@ -81,6 +85,10 @@ EigenOption::PreconType EigenOption::getPreconType(
{
return PreconType::DIAGONAL;
}
+ if (precon_name == "LeastSquareDIAGONAL")
+ {
+ return PreconType::LeastSquareDIAGONAL;
+ }
if (precon_name == "ILUT")
{
return PreconType::ILUT;
@@ -95,6 +103,8 @@ std::string EigenOption::getSolverName(SolverType const solver_type)
{
case SolverType::CG:
return "CG";
+ case SolverType::LeastSquareCG:
+ return "LeastSquareCG";
case SolverType::BiCGSTAB:
return "BiCGSTAB";
case SolverType::BiCGSTABL:
@@ -121,6 +131,8 @@ std::string EigenOption::getPreconName(PreconType const precon_type)
return "NONE";
case PreconType::DIAGONAL:
return "DIAGONAL";
+ case PreconType::LeastSquareDIAGONAL:
+ return "LeastSquareDIAGONAL";
case PreconType::ILUT:
return "ILUT";
}
diff --git a/MathLib/LinAlg/Eigen/EigenOption.h b/MathLib/LinAlg/Eigen/EigenOption.h
index 54815c948b92818850031565d9b59dc20e1c1741..217d69eae31e94ca97a8514c7eb2efb17c2428cf 100644
--- a/MathLib/LinAlg/Eigen/EigenOption.h
+++ b/MathLib/LinAlg/Eigen/EigenOption.h
@@ -21,6 +21,7 @@ struct EigenOption final
enum class SolverType : short
{
CG,
+ LeastSquareCG,
BiCGSTAB,
BiCGSTABL,
IDRS,
@@ -35,6 +36,7 @@ struct EigenOption final
{
NONE,
DIAGONAL,
+ LeastSquareDIAGONAL,
ILUT
};
diff --git a/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h b/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h
index 23763277d0a9241931e0537cb5330f1eb52f5654..3543d65533131c26542f07f35a48713e88a9368e 100644
--- a/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h
+++ b/MathLib/LinAlg/EigenLis/EigenLisLinearSolver.h
@@ -51,6 +51,9 @@ public:
bool solve(EigenMatrix& A, EigenVector& b, EigenVector& x);
+ /// Get, if the solver can handle rectangular equation systems
+ bool canSolveRectangular() const { return false; }
+
private:
bool solve(LisMatrix& A, LisVector& b, LisVector& x);
std::string lis_options_;
diff --git a/MathLib/LinAlg/PETSc/PETScLinearSolver.cpp b/MathLib/LinAlg/PETSc/PETScLinearSolver.cpp
index 7310848f3ea60f118df33340b5dca8ea1ed13060..1fc14a8bd588b019e9d3dbf442787d5759dd2154 100644
--- a/MathLib/LinAlg/PETSc/PETScLinearSolver.cpp
+++ b/MathLib/LinAlg/PETSc/PETScLinearSolver.cpp
@@ -40,6 +40,10 @@ PETScLinearSolver::PETScLinearSolver(std::string const& prefix,
KSPSetInitialGuessNonzero(solver_, PETSC_TRUE);
KSPSetFromOptions(solver_); // set run-time options
+
+ KSPType ksp_type;
+ KSPGetType(solver_, &ksp_type);
+ can_solve_rectangular_ = canSolverHandleRectangular(ksp_type);
}
bool PETScLinearSolver::solve(PETScMatrix& A, PETScVector& b, PETScVector& x)
diff --git a/MathLib/LinAlg/PETSc/PETScLinearSolver.h b/MathLib/LinAlg/PETSc/PETScLinearSolver.h
index 0dfcbc359560f5945d8996c3b1ac0ff1a04ac58c..59c1ad0d8d2ba9d16a41aa6a339b7ee9d7512287 100644
--- a/MathLib/LinAlg/PETSc/PETScLinearSolver.h
+++ b/MathLib/LinAlg/PETSc/PETScLinearSolver.h
@@ -18,6 +18,8 @@
#include <petscksp.h>
+#include <algorithm>
+#include <array>
#include <string>
#include "PETScMatrix.h"
@@ -62,10 +64,26 @@ public:
/// Get elapsed wall clock time.
double getElapsedTime() const { return elapsed_ctime_; }
+ /// Get, if the solver can handle rectangular equation systems
+ bool canSolveRectangular() const { return can_solve_rectangular_; }
+
private:
+ bool canSolverHandleRectangular(std::string_view ksp_type)
+ {
+ // List of KSP types that can handle rectangular matrices
+ constexpr auto rectangular_solvers = std::to_array<std::string_view>(
+ {KSPGMRES, KSPFGMRES, KSPBCGS, KSPBCGSL, KSPTFQMR, KSPCGS});
+
+ return std::ranges::any_of(rectangular_solvers,
+ [&](const auto& solver)
+ { return solver == ksp_type; });
+ }
+
KSP solver_; ///< Solver type.
PC pc_; ///< Preconditioner type.
+ bool can_solve_rectangular_ = false;
+
double elapsed_ctime_ = 0.0; ///< Clock time
};
diff --git a/NumLib/ODESolver/NonlinearSolver.cpp b/NumLib/ODESolver/NonlinearSolver.cpp
index eb533380fd16d64f63b39752765ace7c16bba02c..516ffa207d8dced39eeda68dc48909cd6a7ffb3a 100644
--- a/NumLib/ODESolver/NonlinearSolver.cpp
+++ b/NumLib/ODESolver/NonlinearSolver.cpp
@@ -170,8 +170,18 @@ NonlinearSolverStatus NonlinearSolver<NonlinearSolverTag::Picard>::solve(
sys.getRhs(*x_prev[process_id], rhs);
// Normalize the linear equation system, if required
- if (sys.requiresNormalization())
+ if (sys.requiresNormalization() &&
+ !_linear_solver.canSolveRectangular())
+ {
sys.getAandRhsNormalized(A, rhs);
+ WARN(
+ "The equation system is rectangular, but the current linear "
+ "solver only supports square systems. "
+ "The system will be normalized, which lead to a squared "
+ "condition number and potential numerical issues. "
+ "It is recommended to use a solver that supports rectangular "
+ "equation systems for better numerical stability.");
+ }
INFO("[time] Assembly took {:g} s.", time_assembly.elapsed());
diff --git a/ProcessLib/HeatTransportBHE/Tests.cmake b/ProcessLib/HeatTransportBHE/Tests.cmake
index 269f8d3089d311116151f077352c64231fc671fd..ddaa11ce26d82c80d1c9cfb4cddff222fd306dd8 100644
--- a/ProcessLib/HeatTransportBHE/Tests.cmake
+++ b/ProcessLib/HeatTransportBHE/Tests.cmake
@@ -34,12 +34,26 @@ AddTest(
WRAPPER time
TESTER vtkdiff
REQUIREMENTS NOT OGS_USE_MPI
- RUNTIME 20
+ RUNTIME 3
DIFF_DATA
sandwich_ts_10_t_600.000000.vtu sandwich_algebraic_bc_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 1e-6
sandwich_ts_10_t_600.000000.vtu sandwich_algebraic_bc_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-9
)
+AddTest(
+ NAME HeatTransportBHE_1U_3D_bhe_sandwich_algebraicBC_LSCG
+ PATH Parabolic/T/3D_BHE_Sandwich
+ EXECUTABLE ogs
+ EXECUTABLE_ARGS sandwich_algebraicBC_LSCG.xml
+ WRAPPER time
+ TESTER vtkdiff
+ REQUIREMENTS NOT OGS_USE_MPI
+ RUNTIME 3
+ DIFF_DATA
+ sandwich_ts_10_t_600.000000.vtu sandwich_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 1e-6
+ sandwich_ts_10_t_600.000000.vtu sandwich_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-9
+)
+
AddTest(
NAME HeatTransportBHE_1U_3D_bhe_sandwich_fixed_power
PATH Parabolic/T/3D_BHE_Sandwich
@@ -57,7 +71,7 @@ AddTest(
AddTest(
NAME HeatTransportBHE_1U_3D_bhe_sandwich_fixed_power_algebraicBC
PATH Parabolic/T/3D_BHE_Sandwich
- RUNTIME 100
+ RUNTIME 3
EXECUTABLE ogs
EXECUTABLE_ARGS sandwich_fixed_power_algebraicBC.xml
WRAPPER time
@@ -68,6 +82,20 @@ AddTest(
sandwich_fixed_power_ts_10_t_600.000000.vtu sandwich_fixed_power_algebraic_bc_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 1e-6
)
+AddTest(
+ NAME HeatTransportBHE_1U_3D_bhe_sandwich_fixed_power_algebraicBC_LSCG
+ PATH Parabolic/T/3D_BHE_Sandwich
+ RUNTIME 3
+ EXECUTABLE ogs
+ EXECUTABLE_ARGS sandwich_fixed_power_algebraicBC_LSCG.xml
+ WRAPPER time
+ TESTER vtkdiff
+ REQUIREMENTS NOT OGS_USE_MPI
+ DIFF_DATA
+ sandwich_fixed_power_ts_10_t_600.000000.vtu sandwich_fixed_power_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 5e-3
+ sandwich_fixed_power_ts_10_t_600.000000.vtu sandwich_fixed_power_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-6
+)
+
AddTest(
NAME HeatTransportBHE_1U_3D_beier_sandbox
PATH Parabolic/T/3D_Beier_sandbox
@@ -96,6 +124,20 @@ AddTest(
beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_newton_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 1e-13
)
+AddTest(
+ NAME HeatTransportBHE_1U_3D_MassLumping
+ PATH Parabolic/T/3D_Beier_sandbox
+ EXECUTABLE ogs
+ EXECUTABLE_ARGS beier_sandbox_MassLumping.xml
+ WRAPPER time
+ TESTER vtkdiff
+ REQUIREMENTS NOT OGS_USE_MPI
+ RUNTIME 20
+ DIFF_DATA
+ beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_mass_lumping_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 1e-6
+ beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_mass_lumping_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 1e-4
+)
+
AddTest(
NAME HeatTransportBHE_1U_3D_beier_sandbox_binary_curve
PATH Parabolic/T/3D_Beier_sandbox
@@ -118,24 +160,24 @@ AddTest(
WRAPPER time
TESTER vtkdiff
REQUIREMENTS NOT OGS_USE_MPI
- RUNTIME 20
+ RUNTIME 3
DIFF_DATA
beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_algebraic_bc_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 5e-7
beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_algebraic_bc_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-10
)
AddTest(
- NAME HeatTransportBHE_1U_3D_MassLumping
+ NAME HeatTransportBHE_1U_3D_beier_sandbox_algebraicBC_LSCG
PATH Parabolic/T/3D_Beier_sandbox
EXECUTABLE ogs
- EXECUTABLE_ARGS beier_sandbox_MassLumping.xml
+ EXECUTABLE_ARGS beier_sandbox_algebraicBC_LSCG.xml
WRAPPER time
TESTER vtkdiff
REQUIREMENTS NOT OGS_USE_MPI
- RUNTIME 20
+ RUNTIME 3
DIFF_DATA
- beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_mass_lumping_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 1e-6
- beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_mass_lumping_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 1e-4
+ beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 5e-7
+ beier_sandbox_ts_10_t_600.000000.vtu beier_sandbox_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-10
)
AddTest(
@@ -155,7 +197,7 @@ AddTest(
AddTest(
NAME HeatTransportBHE_1U_beier_sandbox_fixed_power_constant_flow_algebraicBC
PATH Parabolic/T/3D_Beier_sandbox
- RUNTIME 220
+ RUNTIME 3
EXECUTABLE ogs
EXECUTABLE_ARGS fixed_power_constant_flow_algebraicBC.xml
WRAPPER time
@@ -166,6 +208,20 @@ AddTest(
fixed_power_constant_flow_ts_10_t_600.000000.vtu fixed_power_constant_flow_algebraic_bc_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-9
)
+AddTest(
+ NAME HeatTransportBHE_1U_beier_sandbox_fixed_power_constant_flow_algebraicBC_LSCG
+ PATH Parabolic/T/3D_Beier_sandbox
+ RUNTIME 3
+ EXECUTABLE ogs
+ EXECUTABLE_ARGS fixed_power_constant_flow_algebraicBC_LSCG.xml
+ WRAPPER time
+ TESTER vtkdiff
+ REQUIREMENTS NOT OGS_USE_MPI
+ DIFF_DATA
+ fixed_power_constant_flow_ts_10_t_600.000000.vtu fixed_power_constant_flow_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_BHE1 temperature_BHE1 0 1e-4
+ fixed_power_constant_flow_ts_10_t_600.000000.vtu fixed_power_constant_flow_algebraic_bc_LSCG_ts_10_t_600.000000.vtu temperature_soil temperature_soil 0 5e-9
+)
+
AddTest(
NAME HeatTransportBHE_coaxial_pipe_3D_deep_BHE_CXA
PATH Parabolic/T/3D_deep_BHE
diff --git a/Tests/Data/Parabolic/T/3D_BHE_Sandwich/sandwich_algebraicBC_LSCG.xml b/Tests/Data/Parabolic/T/3D_BHE_Sandwich/sandwich_algebraicBC_LSCG.xml
new file mode 100644
index 0000000000000000000000000000000000000000..7aae83c25dd8cd11ff32bd32b88b3f070c8a9b20
--- /dev/null
+++ b/Tests/Data/Parabolic/T/3D_BHE_Sandwich/sandwich_algebraicBC_LSCG.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<OpenGeoSysProjectDiff base_file="sandwich.prj">
+ <add sel="/*/processes/process">
+ <use_algebraic_bc>true</use_algebraic_bc>
+ </add>
+ <add sel="/*/processes/process">
+ <weighting_factor>100</weighting_factor>
+ </add>
+ <add sel="/*/processes/process">
+ <linear>true</linear>
+ </add>
+ <replace sel="/*/time_loop/output/prefix/text()">sandwich_algebraic_bc_LSCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/solver_type/text()">LeastSquareCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/precon_type/text()">LeastSquareDIAGONAL</replace>
+</OpenGeoSysProjectDiff>
diff --git a/Tests/Data/Parabolic/T/3D_BHE_Sandwich/sandwich_fixed_power_algebraicBC_LSCG.xml b/Tests/Data/Parabolic/T/3D_BHE_Sandwich/sandwich_fixed_power_algebraicBC_LSCG.xml
new file mode 100644
index 0000000000000000000000000000000000000000..50024b03ab9ca6c09871ea0cac7dd710af59a062
--- /dev/null
+++ b/Tests/Data/Parabolic/T/3D_BHE_Sandwich/sandwich_fixed_power_algebraicBC_LSCG.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<OpenGeoSysProjectDiff base_file="sandwich_fixed_power.prj">
+ <add sel="/*/processes/process">
+ <use_algebraic_bc>true</use_algebraic_bc>
+ </add>
+ <add sel="/*/processes/process">
+ <weighting_factor>100</weighting_factor>
+ </add>
+ <add sel="/*/processes/process">
+ <linear>true</linear>
+ </add>
+ <replace sel="/*/time_loop/output/prefix/text()">sandwich_fixed_power_algebraic_bc_LSCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/solver_type/text()">LeastSquareCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/precon_type/text()">LeastSquareDIAGONAL</replace>
+</OpenGeoSysProjectDiff>
diff --git a/Tests/Data/Parabolic/T/3D_Beier_sandbox/beier_sandbox_algebraicBC_LSCG.xml b/Tests/Data/Parabolic/T/3D_Beier_sandbox/beier_sandbox_algebraicBC_LSCG.xml
new file mode 100644
index 0000000000000000000000000000000000000000..9c9ee6554bb0b061c5715547b009dd6fce7f21d4
--- /dev/null
+++ b/Tests/Data/Parabolic/T/3D_Beier_sandbox/beier_sandbox_algebraicBC_LSCG.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<OpenGeoSysProjectDiff base_file="beier_sandbox.prj">
+ <add sel="/*/processes/process">
+ <use_algebraic_bc>true</use_algebraic_bc>
+ </add>
+ <add sel="/*/processes/process">
+ <weighting_factor>100</weighting_factor>
+ </add>
+ <add sel="/*/processes/process">
+ <linear>true</linear>
+ </add>
+ <replace sel="/*/time_loop/output/prefix/text()">beier_sandbox_algebraic_bc_LSCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/solver_type/text()">LeastSquareCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/precon_type/text()">LeastSquareDIAGONAL</replace>
+</OpenGeoSysProjectDiff>
diff --git a/Tests/Data/Parabolic/T/3D_Beier_sandbox/fixed_power_constant_flow_algebraicBC_LSCG.xml b/Tests/Data/Parabolic/T/3D_Beier_sandbox/fixed_power_constant_flow_algebraicBC_LSCG.xml
new file mode 100644
index 0000000000000000000000000000000000000000..8cc4e749e8a3d3d7c8a7eb969c423318ee09473c
--- /dev/null
+++ b/Tests/Data/Parabolic/T/3D_Beier_sandbox/fixed_power_constant_flow_algebraicBC_LSCG.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<OpenGeoSysProjectDiff base_file="fixed_power_constant_flow.prj">
+ <add sel="/*/processes/process">
+ <use_algebraic_bc>true</use_algebraic_bc>
+ </add>
+ <add sel="/*/processes/process">
+ <weighting_factor>100</weighting_factor>
+ </add>
+ <add sel="/*/processes/process">
+ <linear>true</linear>
+ </add>
+ <replace sel="/*/time_loop/output/prefix/text()">fixed_power_constant_flow_algebraic_bc_LSCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/solver_type/text()">LeastSquareCG</replace>
+ <replace sel="/*/linear_solvers/linear_solver/eigen/precon_type/text()">LeastSquareDIAGONAL</replace>
+</OpenGeoSysProjectDiff>