collect multiple restart files in a format.

examples/Carbyne/carbyne.rom.cfg

@@ -18,14 +18,17 @@ pseudopotential=pseudo.C_ONCV_PBE_SG15
 [Run]
 type=QUENCH
 [Quench]
-max_steps=10
+max_steps=5
 atol=1.e-8
 [Orbitals]
 initial_type=Fourier
 [Restart]
 output_level=4
-# input_level=4
-# input_filename=snapshot0_24_109_22_36
+input_level=4
+input_filename=snapshot0_000
 
 [ROM.offline]
-restartFilename=snapshot0_24_109_22_39
+restart_filefmt=snapshot0_%03d
+restart_min_idx=0
+restart_max_idx=1
+basis_file=carom

src/Control.cc

@@ -2063,7 +2063,11 @@ void Control::setROMOptions(const boost::program_options::variables_map& vm)
 
     if (onpe0)
     {
-        rom_pri_option.restart_filename = vm["ROM.offline.restartFilename"].as<std::string>();
+        rom_pri_option.restart_file_fmt = vm["ROM.offline.restart_filefmt"].as<std::string>();
+        rom_pri_option.restart_file_minidx = vm["ROM.offline.restart_min_idx"].as<int>();
+        rom_pri_option.restart_file_maxidx = vm["ROM.offline.restart_max_idx"].as<int>();
+
+        rom_pri_option.basis_file = vm["ROM.offline.basis_file"].as<std::string>();
     }  // onpe0
 
     // synchronize all processors
@@ -2077,7 +2081,8 @@ void Control::syncROMOptions()
 
     MGmol_MPI& mmpi = *(MGmol_MPI::instance());
 
-    mmpi.bcast(rom_pri_option.restart_filename, comm_global_);
+    mmpi.bcast(rom_pri_option.restart_file_fmt, comm_global_);
+    mmpi.bcast(rom_pri_option.basis_file, comm_global_);
 
     auto bcast_check = [](int mpirc) {
         if (mpirc != MPI_SUCCESS)
@@ -2092,5 +2097,11 @@ void Control::syncROMOptions()
     mpirc = MPI_Bcast(&rom_stage, 1, MPI_SHORT, 0, comm_global_);
     bcast_check(mpirc);
 
+    mpirc = MPI_Bcast(&rom_pri_option.restart_file_minidx, 1, MPI_INT, 0, comm_global_);
+    bcast_check(mpirc);
+
+    mpirc = MPI_Bcast(&rom_pri_option.restart_file_maxidx, 1, MPI_INT, 0, comm_global_);
+    bcast_check(mpirc);
+
     rom_pri_option.rom_stage = static_cast<ROMStage>(rom_stage);
 }

src/rom_Control.h

@@ -27,7 +27,10 @@ enum class ROMStage
 /* Stored as a private member variable of Control class */
 struct ROMPrivateOptions
 {
-    std::string restart_filename = "";
+    std::string restart_file_fmt = "";
+    int restart_file_minidx = -1;
+    int restart_file_maxidx = -1;
+    std::string basis_file = "";
     ROMStage rom_stage = ROMStage::UNSUPPORTED;
 };
 

src/rom_workflows.cc

@@ -8,20 +8,63 @@
 // Please also read this link https://github.com/llnl/mgmol/LICENSE
 
 #include "rom_workflows.h"
+#include <memory>
+#include <string>
+#include <stdexcept>
+
+template<typename ... Args>
+std::string string_format( const std::string& format, Args ... args )
+{
+    int size_s = std::snprintf( nullptr, 0, format.c_str(), args ... ) + 1; // Extra space for '\0'
+    if( size_s <= 0 ){ throw std::runtime_error( "Error during formatting." ); }
+    auto size = static_cast<size_t>( size_s );
+    std::unique_ptr<char[]> buf( new char[ size ] );
+    std::snprintf( buf.get(), size, format.c_str(), args ... );
+    return std::string( buf.get(), buf.get() + size - 1 ); // We don't want the '\0' inside
+}
 
 template <class OrbitalsType>
 void readRestartFiles(MGmolInterface *mgmol_)
 {
     Control& ct              = *(Control::instance());
     ROMPrivateOptions rom_options = ct.getROMOptions();
+    assert(rom_options.restart_file_minidx >= 0);
+    assert(rom_options.restart_file_maxidx >= 0);
+    const int minidx = rom_options.restart_file_minidx;
+    const int maxidx = rom_options.restart_file_maxidx;
+    const int num_restart = maxidx - minidx + 1;
 
     MGmol<OrbitalsType> *mgmol = static_cast<MGmol<OrbitalsType> *>(mgmol_);
+    OrbitalsType *orbitals = nullptr;
+    std::string filename;
 
-    OrbitalsType *orbitals = mgmol->loadOrbitalFromRestartFile(rom_options.restart_filename);
+    /* Read the first snapshot to determin dimension and number of snapshots */
+    filename = string_format(rom_options.restart_file_fmt, minidx);
+    orbitals = mgmol->loadOrbitalFromRestartFile(filename);
+    const int dim = orbitals->getLocNumpt();
+    const int chrom_num = orbitals->chromatic_number();
+    const int totalSamples = orbitals->chromatic_number() * num_restart;
+    delete orbitals;
 
-    mgmol->save_orbital_snapshot("test", *orbitals);
+    /* Initialize libROM classes */
+    CAROM::Options svd_options(dim, totalSamples, 1);
+    CAROM::BasisGenerator basis_generator(svd_options, false, rom_options.basis_file);
+
+    /* Collect the restart files */
+    for (int k = minidx; k <= maxidx; k++)
+    {
+        filename = string_format(rom_options.restart_file_fmt, k);
+        orbitals = mgmol->loadOrbitalFromRestartFile(filename);
+        assert(dim == orbitals->getLocNumpt());
+        assert(chrom_num == orbitals->chromatic_number());
 
-    delete orbitals;
+        for (int i = 0; i < chrom_num; ++i)
+            basis_generator.takeSample(orbitals->getPsi(i));
+
+        delete orbitals;
+    }
+    basis_generator.writeSnapshot();
+    basis_generator.endSamples();
 }
 
 template void readRestartFiles<LocGridOrbitals>(MGmolInterface *mgmol_);

src/tools/OptionDescription.cc

@@ -320,6 +320,12 @@ void setupHiddenOption(po::options_description &hidden)
 void setupROMConfigOption(po::options_description &rom_cfg)
 {
     rom_cfg.add_options()
-        ("ROM.offline.restartFilename", po::value<string>()->required(),
-            "File name to read for snapshots."); 
+        ("ROM.offline.restart_filefmt", po::value<string>()->required(),
+            "File name format to read for snapshots.")
+        ("ROM.offline.restart_min_idx", po::value<int>()->required(),
+            "Minimum index for snapshot file format.")
+        ("ROM.offline.restart_max_idx", po::value<int>()->required(),
+            "Maximum index for snapshot file format.")
+        ("ROM.offline.basis_file", po::value<string>()->required(),
+            "File name for libROM snapshot/POD matrices.");
 }