# Quick start guide



## Getting the files

Go to the [public repository on Github](https://github.com/cni-iisc/epidemic-simulator/) and ‘clone’ the repository by clicking on the ‘Code’ button and follow the instructions. You can do this in a folder of your choice.

```bash
$ ~/tutorial > cd epidemic-simulator
$ ~/tutorial/epidemic-simulator > python3 -m venv edaDev
$ ~/tutorial/epidemic-simulator > source edaDev/bin/activate
(edaDev) $ ~/tutorial/epidemic-simulator >
```

## Repository structure

The repository has three main components that we would be using which are in three different folders:

- ``staticInst``: This folder contains the python code that generates the city once it is provided the demographics/employment etc. information.
- ``cpp_simulator``: This contains the C++ code for the simulator
- ``simulator``: This contains the javascript version of the simulator 
- ``cpp_simulator_calibration``: This contains some python scripts that is used for calibrating some of the values.


We will first do the city building.

## Building the synthetic city

In order to run the city building script, we would need to get a few python packages. We recommend using a virtual environment to install the packages, since it isolates the pacakges to be installed from your system-wide python setup. More infomration is available in [setting up the python environment](/sections/instantiation/setting_up_py_env.md) page.

```bash
(edaDev) $ ~/tutorial/epidemic-simulator > pip install -r staticInst/requirements.txt
```

With these packages installed, we are now ready to actually build the city.

The demographics, employment etc. data is present in the folder ``staticInst/data/base/[city name]``. We will work with Mumbai and generate the city.

```bash
(edaDev) $ ~/tutorial/epidemic-simulator > cd staticInst
(edaDev) $ ~/tutorial/epidemic-simulator/staticInst > python CityGen.py -h
usage: CityGen.py [-h] [-n N] [-i I] [-o O] [--validate] [-s S]

Create mini-city for COVID-19 simulation

optional arguments:
  -h, --help  show this help message and exit
  -n N        target population
  -i I        input folder
  -o O        output folder
  --validate  script for validation plots on
  -s S        [for debug] restore random seed from folder
```

With the syntax in mind, let us go ahead and build the city (of 150k size).

```bash
(edaDev) $ ~/tutorial/epidemic-simulator/staticInst > python CityGen.py -n 150000 -i data/base/mumbai -o data/mumbai_150k --validate
input_folder: data/base/mumbai
output_folder: data/mumbai_150k

(Distance kernel parameters provided.)
createHouses                  ...	done. (6242 ms)
populateHouses                ...	done. (22332 ms)
assignSchools                 ...	done. (287 ms)
assignWorkplaces              ...	done. (6630 ms)

City: mumbai
Population: 150071
Number of wards: 48
Has slums: True

Number of houses: 33259
Number of schools: 107
Number of workplaces: 2899
Number of workers: 60606

dump_files                    ...	done. (1239 ms)
validate_ages                 ...	done. (452 ms)
validate_householdsizes       ...	done. (158 ms)
validate_schoolsizes          ...	done. (162 ms)
validate_workplacesizes       ...	done. (801 ms)
validate_commutedistances     ...	done. (1819 ms)
```


We now have a 150k version of Mumbai instantiated in ``staticInst/data/mumbai_150k``.


## Simulating a test run

Now that we have generated a city, we can go ahead and execute a test run to see if everything is working fine.

```bash
(edaDev) $ ~/tutorial/epidemic-simulator/staticInst > cd ../cpp-simulator
(edaDev) $ ~/tutorial/epidemic-simulator/cpp-simulator > make all
```


**Note for Mac users**: The above make command will complain saying that there is no option fopenmp as Mac does not by default have that. In that case, instead run the following command:

```bash
(edaDev) $ ~/tutorial/epidemic-simulator/cpp-simulator > make all -f Makefile_np
```

We can now execute a test run. Let us first create the directory where we want to store the outputs of the simulation.

```bash
(edaDev) $ ~/tutorial/epidemic-simulator/cpp-simulator > mkdir -p outputs/mumbai_test_run
```

… and now the actual simulation

```bash
(edaDev) $ ~/tutorial/epidemic-simulator/cpp-simulator > ./drive_simulator --NUM_DAYS 10 --SEED_FIXED_NUMBER --INIT_FIXED_NUMBER_INFECTED 100 --INTERVENTION 0 --input_directory ../staticInst/data/mumbai_150k --output_directory outputs/mumbai_test_run
```

You should now have a whole bunch of files in the ``cpp-simulator/outputs/mumbai_test_run`` folder.