Move precision detection into the dataset reader function

Author: Martin D. Weinberg

src/Component.cc

@@ -1538,11 +1538,6 @@ void Component::read_bodies_and_distribute_hdf5(void)
   //
   HighFive::Group particles_group = file.getGroup("particles");
 
-  // Detect precision by inspecting first dataset "m"
-  //
-  HighFive::DataSet m_dataset = particles_group.getDataSet("m");
-  size_t precision  = detect_precision(m_dataset);
-
   // Variant for flexible reading and access of float or double datasets
   //
   using FloatDataVariant = std::variant<std::vector<float>, std::vector<double>>;
@@ -1579,10 +1574,11 @@ void Component::read_bodies_and_distribute_hdf5(void)
 
   // Lambda to read float or double based on precision flag
   //
-  auto read_dataset = [&particles_group, precision]
+  auto read_dataset = [this, &particles_group]
     (const std::string& name, size_t offset, size_t batch) -> FloatData {
 
     HighFive::DataSet dataset = particles_group.getDataSet(name);
+    size_t precision  = detect_precision(dataset);
 
     // Fetch the dimensions (e.g., [rows, cols])
     size_t total = dataset.getSpace().getDimensions()[0];

utils/PhaseSpace/hdf5bods.cc

@@ -437,7 +437,6 @@ struct ParticleDataVariant
   size_t num_particles = 0;
   size_t num_aux_ints = 0;
   size_t num_aux_floats = 0;
-  FloatPrecision precision;
 };
 
 // Detect float precision by inspecting dataset type
@@ -475,20 +474,17 @@ ParticleDataVariant read_hdf5_data(const std::string& hdf5_file)
   // Open particles group
   Group particles_group = file.getGroup("particles");
 
-  // Detect precision by inspecting first dataset "m"
-  DataSet m_dataset = particles_group.getDataSet("m");
-  FloatPrecision precision = detect_precision(m_dataset);
-
   ParticleDataVariant data;
   data.num_particles  = num_particles;
   data.num_aux_ints   = num_aux_ints;
   data.num_aux_floats = num_aux_floats;
-  data.precision      = precision;
-
-  // Precision is available in data.precision; caller decides whether to print it.
 
   // Lambda to read float or double based on precision
-  auto read_dataset = [&particles_group, precision](const std::string& name) -> FloatData {
+  auto read_dataset = [&particles_group](const std::string& name) -> FloatData {
+    // Detect precision by inspecting dataset
+    DataSet dataset = particles_group.getDataSet(name);
+    FloatPrecision precision = detect_precision(dataset);
+
     if (precision == FloatPrecision::FLOAT32) {
       return particles_group.getDataSet(name).read<std::vector<float>>();
     } else {
@@ -598,11 +594,9 @@ void hdf5_to_ascii(const std::string& hdf5_file, const std::string& ascii_file,
   }
   outfile.close();
 
-  std::string precision_str = (data.precision == FloatPrecision::FLOAT32) 
-                              ? "float32" : "float64";
   if (verbose)
-    std::cout << "Successfully wrote " << data.num_particles << " particles to " 
-	      << ascii_file << " (" << precision_str << ")" << std::endl;
+    std::cout << "Successfully wrote " << data.num_particles
+	      << " particles to " << ascii_file << std::endl;
 }
 
 // Main function with command-line parsing