# Dragon v5.1

This is the repository for the Dragon code.
Version5 is a 64-bit clean distribution of the reactor physics codes developed at Polytechnique Montréal.


## License

The license is [GNU General Public License](http://www.gnu.org/licenses/lgpl.html).


## Documentation

For comprehensive documentation please refer to the [Merlin site](http://merlin.polymtl.ca/version5.htm).
Additionally, you can build the documentation yourself using Latex, see the subdirectory [doc](./doc) for more.


## Dependencies

In order to compile and run Dragon you must have a Fortran compiler (2003 or later standard) and Python3.

Optional dependencies are [OpenMP](https://www.openmp.org/resources/openmp-compilers-tools/) and [HDF5](https://www.hdfgroup.org/download-hdf5/).


## Installation

Dragon is supported on Linux and Unix machines. For Windows users we recommend using the Windows Subsystem for Linux (WSL).

The installation is based on `make`, particularly `gmake` for Unix systems.

Please go to the [Merlin site](http://merlin.polymtl.ca/version5.htm) for comprehensive installation instructions.


## Run the code

A minimum set of cross section files can be found on the [Merlin site](http://merlin.polymtl.ca/version5.htm), for more extensive work download the required files from the NEA data repository [here](../libraries/).

**Please note that you must preserve the directory structure**. This can be achieved by doing the following:

If you want all data (note the disk space ~10GB) follow these steps:

```bash
mkdir dragon
cd dragon
git clone https://git.oecd-nea.org/dragon/5.1
git clone https://git.oecd-nea.org/dragon/libraries
```

For those with limited disk space, you will need to specify which data files you want.

For example:

```bash
mkdir dragon
cd dragon
git clone https://git.oecd-nea.org/dragon/5.1
GIT_LFS_SKIP_SMUDGE=1 git clone https://git.oecd-nea.org/dragon/libraries
cd libraries
# For JEFF 3.1.1 SHEM 361 use the following
git lfs pull -I l_endian/draglibJeff3p1p1SHEM361_v5p1.gz
```

## Docker

If you don't want to compile the code on your machine, we offer pre-built Docker images for you to use to bypass this, and you just require docker installed on your machine.

For Windows users you can use [Docker Desktop](https://docs.docker.com/desktop/setup/install/windows-install/) (if you don't have WSL).


### Get image

To get a docker images (Ubuntu 22.04) with PHITS already setup and paths set, you may pull this image via:

```bash
docker pull docker.oecd-nea.org/dragon/5.1:v5.1.0-slim
```

### Running image

A template command is provided below and you only need to change the text in the `<>` sections, specific to your installation. Note that the paths on the right hand side of the colon (:) should be to your **host** machine, the paths on the right hand side do not need to be changed and match to paths inside the docker container.


```bash
docker run -v <my_path_to_libs>:/dragon/libraries:ro
           -v <my_path_to_inputs>:/dragon/5.1/Donjon/data/:ro
           -v <my_path_to_outputs>:/dragon/5.1/Donjon/Linux_x86_64
           docker.oecd-nea.org/dragon/5.1:v5.1.0-slim
           "-q <my_input_file.x2m>"
```

You therefore need 4 parameters to set:

1. `<my_path_to_libs>` should point to the directory containing your Dragon nuclear data library file (`*.gz`).

2. `<my_path_to_inputs>` should point to a directory on your host machine containing the input data files (`*.x2m` and other related files). This should be a different directory to number 1.

3. `<my_path_to_outputs>` should point to a directory on your host machine which will be used to keep the output files from each code run i.e (including the `*.result` file). This should be different to 1. and 2.

4. `<my_input_file.x2m>` should be the name of the input data file which should exist in directory number 2.


An example of this is given below:


```bash
docker run -v /home/user/dragon/libraries:/dragon/libraries:ro
           -v /home/user/dragon/inputs:/dragon/5.1/Donjon/data/:ro
           -v /home/user/dragon/outputs:/dragon/5.1/Donjon/Linux_x86_64
           docker.oecd-nea.org/dragon/5.1:v5.1.0-slim
           "-q VanDerGucht.x2m"
```


given the following directory contents:

```bash
$ls /home/user/dragon/libraries
README.md  ascii  hdf5  l_endian  pynjoy
```

```bash
$ls /home/user/dragon/inputs
VanDerGucht.access  VanDerGucht.x2m  VanDerGucht_proc
```

will give me the following outputs

```bash
$ls /home/user/dragon/outputs
VanDerGucht.result
```