readme and path

opening-hdf5/README.md

@@ -0,0 +1,21 @@
+## Location of data
+The data path is hardcoded such that the following tree structure is assumed:
+```
+data/
+  grid.h5
+  hydrodynamic_U.h5
+  hydrodynamic_V.h5
+interactive-track-and-trace/
+  opening-hdf5/
+     ...
+```
+
+## Compiling
+Makes use of `mdspan` which is not supported by GCC libstdc++ at time of writing. See [compiler support](https://en.cppreference.com/w/cpp/compiler_support/23) for `mdspan`.
+Let the current directory be the `src` directory. Run:
+```shell
+mkdir build
+cd build
+cmake ..
+make
+```

opening-hdf5/src/main.cpp

@@ -85,7 +85,7 @@ pair<vector<T>, std::dextents<std::size_t, 3>> get3DMat(NcVar var) {
 }
 
 int main () {
-  netCDF::NcFile data("../../../hdf5/hydrodynamic_U.h5", netCDF::NcFile::read);
+  netCDF::NcFile data("../../../../data/hydrodynamic_U.h5", netCDF::NcFile::read);
 
   multimap< string, NcVar > vars = data.getVars();