HDF5 minimal example

hdf5.cpp

@@ -31,11 +31,15 @@ int main(int argc, char** argv)
   // Let's create some sample data!
   // Even MPI ranks have (100 + rank) integers worth of data, oddballs don't
   // have any data.
-  std::vector<int> v((comm_rank%2 == 0) ? 100+comm_rank : 0, comm_rank);
+  std::vector<int> v(100 + comm_rank, comm_rank+10);
 
   // The extent of the dataspace in the file can be computed accordingly.
-  hsize_t size = 100 * (comm_size/2 + comm_size%2)
-    + (comm_size-1)/2 * ((comm_size-1)/2+1);
+  hsize_t size = 100 * (comm_size / 2 + comm_size % 2) +
+                 (comm_size - 1) / 2 * ((comm_size - 1) / 2 + 1);
+  printf("Size %d", size);
+
+  size = comm_size * 100 + (comm_size) * (comm_size - 1) / 2;
+  printf("Size %d", size);
 
   // Make a dataset!
   // I can't believe that takes 10 lines of code :-(
@@ -45,29 +49,30 @@ int main(int argc, char** argv)
   hid_t dcpl = H5Pcreate(H5P_DATASET_CREATE);
   assert(dcpl >= 0);
   assert(H5Pset_chunk(dcpl, 1, &CHUNK_SIZE) >= 0);
-  hid_t dset = H5Dcreate(file, "1D", H5T_STD_I32LE, fspace,
-                         H5P_DEFAULT, dcpl, H5P_DEFAULT);
+  hid_t dset = H5Dcreate(file, "1D", H5T_STD_I32LE, fspace, H5P_DEFAULT, dcpl,
+                         H5P_DEFAULT);
   assert(dset >= 0);
   assert(H5Pclose(dcpl) >= 0);
 
   // Let's get H5Dwriting!
-  hsize_t offset {0}, one {1}, blk { v.size() };
+  hsize_t offset{0}, one{1}, blk{v.size()};
   hid_t mspace = H5Screate_simple(1, &blk, NULL);
-  if (comm_rank%2 == 0)
-    {
-      assert(H5Sselect_all(mspace) >= 0);
-      offset = comm_rank/2 * 100 + (comm_rank-1)/2 * ((comm_rank-1)/2+1);
-      assert(H5Sselect_hyperslab(fspace, H5S_SELECT_SET, &offset, NULL, &one,
-                                 &blk) >= 0);
-    }
-  else
-    {
-      assert(H5Sselect_none(mspace) >= 0);
-      assert(H5Sselect_none(fspace) >= 0);
-    }
-
-  assert(H5Dwrite(dset, H5T_NATIVE_INT, mspace, fspace, H5P_DEFAULT, v.data())
-         >= 0);
+
+  assert(H5Sselect_all(mspace) >= 0);
+  offset =
+      comm_rank / 2 * 100 + (comm_rank - 1) / 2 * ((comm_rank - 1) / 2 + 1);
+
+  offset = comm_rank*100+(comm_rank)*(comm_rank-1)/2;
+
+  printf("offset %d of rank %d \n", offset, comm_rank);
+  assert(H5Sselect_hyperslab(fspace, H5S_SELECT_SET, &offset, NULL, &one,
+                             &blk) >= 0);
+
+  assert(H5Sselect_none(mspace) >= 0);
+  assert(H5Sselect_none(fspace) >= 0);
+
+  assert(H5Dwrite(dset, H5T_NATIVE_INT, mspace, fspace, H5P_DEFAULT,
+                  v.data()) >= 0);
 
   // Clean house!
   assert(H5Sclose(mspace) >= 0);