compilation.md

@@ -35,6 +35,12 @@ cmake . -DMATLIB_VERSION=none -DSPARSE_LIBRARY=none
 make
 ```
 
+To be able to write HDF5 file (assuming you installed the dependancies),
+you have to compile with:
+```shell
+cmake . -DWITH_HDF5=True
+```
+
 If you want to re-build the documentation run:
 ```shell
 make docs