doc: update readme

README.md

@@ -1,6 +1,6 @@
 # Probabilistic Substance Quality Index (PSQI)
 
-This repository contains experimental results for the paper that introduced PSQI index and applied it to water quality measurements conducted in New Moscow region, Russia.
+This repository contains experimental results and source code for the paper that introduced PSQI index and applied it to water quality measurements conducted in New Moscow region, Russia.
 
 # Results
 
@@ -20,3 +20,25 @@ This interactive map of measurements can be opened with [Kepler.gl](https://kepl
 3. Select "Load Map using URL";
 4. Paste [this URL](https://raw.githubusercontent.com/tzoiker/psqi/master/results/map.json) of the raw map.json content file and click "Fetch".
 Alternatively, one may download map.json file and upload it directly after the step 2.
+
+# Source code
+
+* `src/data` - raw data used for experiments;
+* `src/psqi` - main code used for experiments;
+* `src/results` - output of the code execution;
+* `src/playground.ipynb` - jupyter notebook for interactive execution of the code.
+
+## Preparation
+
+1. Install [Conda](https://conda.io/projects/conda/en/latest/user-guide/install/index.html).
+2. Create python environment with `conda create -n psqi python=3.6`.
+3. Install gpytorch with `conda install --name psqi gpytorch==0.3.6 -c gpytorch`.
+4. (Optional) To enable GPU support, install corresponding [pytoch](https://pytorch.org/get-started/previous-versions/#v180) version.
+5. Activate environment with `conda activate psqi`.
+6. Install other dependencies with `pip install -r requirements.txt`.
+7. Install jupyter notebook kernel with `python -m ipykernel install --name=psqi`.
+
+## Running the code
+
+Run jupyter notebook with `jupyter notebook` and open `src/playground.ipynb` in the automatically opened browser window.
+Now jupyter cells can be sequentially executed to reproduce the results.