WIP

include/schaapcommon/h5parm/soltab.h

@@ -196,6 +196,14 @@ class SolTab : private H5::Group {
                                              const std::vector<double>& freqs,
                                              size_t pol, size_t dir,
                                              bool nearest) const;
+  std::tuple<int, int, int, int, int> GetValuesOrWeights(
+      const std::string& val_or_weight, 
+      unsigned int startantenna, unsigned int nantenna, unsigned int antennastep,
+      unsigned int starttimeslot, unsigned int ntime, unsigned int timestep,
+      unsigned int startfreq, unsigned int nfreq, unsigned int freqstep,
+      unsigned int startpol, unsigned int npol, unsigned int polstep,
+      unsigned int startdir, unsigned int ndir, unsigned int dirstep,
+      std::vector<double> &buffer) const;
 
   /// Get the values or weights of this SolTab for a given antenna given an
   /// antenna name, a direction index, and a (range of) times and frequencies.

src/h5parm/soltab.cc

@@ -362,6 +362,104 @@ std::vector<double> SolTab::GetValuesOrWeights(
                              frequencies, sub_array, mem_layout, nearest);
 }
 
+std::tuple<int, int, int, int, int> SolTab::GetValuesOrWeights(
+    const std::string& val_or_weight, 
+    unsigned int startantenna, unsigned int nantenna, unsigned int antennastep,
+    unsigned int starttimeslot, unsigned int ntime, unsigned int timestep,
+    unsigned int startfreq, unsigned int nfreq, unsigned int freqstep,
+    unsigned int startpol, unsigned int npol, unsigned int polstep,
+    unsigned int startdir, unsigned int ndir, unsigned int dirstep,
+    std::vector<double> &buffer) const {
+  H5::DataSet val = openDataSet(val_or_weight);
+
+  // Set offsets and strides
+  std::vector<hsize_t> memdims;
+  std::vector<hsize_t> offsets;
+  std::vector<hsize_t> counts;
+  std::vector<hsize_t> strides;
+  memdims.reserve(axes_.size());
+  offsets.reserve(axes_.size());
+  counts.reserve(axes_.size());
+  strides.reserve(axes_.size());
+
+  for (const AxisInfo& axis_info : axes_) {
+    hsize_t stride = 1;
+    hsize_t count = 1;
+    hsize_t offset = 0;
+    if (axis_info.name == "time") {
+      offset = starttimeslot;
+      stride = timestep;
+      count = ntime;
+    } else if (axis_info.name == "freq") {
+      offset = startfreq;
+      stride = freqstep;
+      count = nfreq;
+    } else if (axis_info.name == "ant") {
+      offset = startantenna;
+      stride = antennastep;
+      count = nantenna;
+    } else if (axis_info.name == "dir") {
+      offset = startdir;
+      stride = dirstep;
+      count = ndir;
+    } else if (axis_info.name == "pol") {
+      offset = startpol;
+      stride = polstep;
+      count = npol;
+    } else if (axis_info.size != 1) {
+      throw std::runtime_error("Axis \"" + axis_info.name +
+                               "\" in H5Parm is not understood");
+    }
+    memdims.push_back(count);
+    offsets.push_back(offset);
+    counts.push_back(count);
+    strides.push_back(stride);
+  }
+
+  int ant_stride = 0;
+  int time_stride = 0;
+  int freq_stride = 0;
+  int pol_stride = 0;
+  int dir_stride = 0;
+  int stride = 1;
+  for (auto axis_info = axes_.rbegin(); axis_info != axes_.rend(); ++axis_info) { 
+    if (axis_info->name == "time") {
+      time_stride = stride;
+      stride *= ntime;
+    } else if (axis_info->name == "freq") {
+      freq_stride = stride;
+      stride *= nfreq;
+    } else if (axis_info->name == "ant") {
+      ant_stride = stride;
+      stride *= nantenna;
+    } else if (axis_info->name == "dir") {
+      dir_stride = stride;
+      stride *= ndir;
+    } else if (axis_info->name == "pol") {
+      pol_stride = stride;
+      stride *= npol;
+    }
+  }
+  buffer.resize(stride);
+
+  H5::DataSpace dataspace = val.getSpace();
+
+  dataspace.selectHyperslab(H5S_SELECT_SET, counts.data(), offsets.data(),
+                            strides.data());
+
+  // Setup memory dataspace
+  H5::DataSpace memspace(axes_.size(), memdims.data());
+
+  try {
+    val.read(buffer.data(), H5::PredType::NATIVE_DOUBLE, memspace, dataspace);
+  } catch (H5::DataSetIException& e) {
+    e.printErrorStack();
+    throw std::runtime_error("Could not read data");
+  }
+  return {ant_stride, time_stride, freq_stride, 
+             pol_stride, dir_stride};
+}
+
 void SolTab::ApplyFlags(std::vector<double>& values,
                         const std::vector<double>& weights) {
   assert(values.size() == weights.size());