Update README.md

README.md

@@ -1 +1,79 @@
-# PGM-index
+<img src="https://gvinciguerra.github.io/PGM-index/images/logo.svg" alt="The PGM-index" style="width: 565px">
+
+The Piecewise Geometric Model index (PGM-index) is a data structure that enables fast point and range searches in arrays of billions of items using orders of magnitude less space than traditional indexes.
+
+[Website](https://gvinciguerra.github.io/PGM-index)
+| [Documentation](https://gvinciguerra.github.io/PGM-index/docs)
+| [Paper](https://arxiv.org/abs/1910.06169)
+| [A³ Lab](http://acube.di.unipi.it)
+
+[![Travis (.org)](https://img.shields.io/travis/gvinciguerra/PGM-index)](https://travis-ci.org/gvinciguerra/PGM-index)
+[![License](https://img.shields.io/github/license/gvinciguerra/PGM-index)](https://github.com/gvinciguerra/PGM-index/blob/master/LICENSE)
+[![GitHub stars](https://img.shields.io/github/stars/gvinciguerra/PGM-index)](https://github.com/gvinciguerra/PGM-index/stargazers)
+
+## Building the code
+
+To download and build the library use the following commands:
+
+```bash
+git clone https://github.com/gvinciguerra/PGM-index.git
+cd PGM-index
+git submodule update --init --recursive
+cmake . -DCMAKE_BUILD_TYPE=Release
+make -j8
+```
+
+Now you can run the unit tests via:
+
+```
+./test/tests
+```
+
+## Minimal example
+
+```cpp
+#include <vector>
+#include <cstdlib>
+#include <iostream>
+#include <algorithm>
+#include "pgm_index.hpp"
+
+int main(int argc, char **argv) {
+    // Generate some random data
+    std::vector<int> dataset(1000000);
+    std::generate(dataset.begin(), dataset.end(), std::rand);
+    dataset.push_back(42);
+    std::sort(dataset.begin(), dataset.end());
+
+    // Construct the PGM-index
+    const int error = 128;
+    PGMIndex<int, error> index(dataset);
+
+    // Query the PGM-index
+    auto q = 42;
+    auto approx_range = index.find_approximate_position(q);
+    auto lo = dataset.cbegin() + approx_range.lo;
+    auto hi = dataset.cbegin() + approx_range.hi;
+    std::cout << *std::lower_bound(lo, hi, q);
+
+    return 0;
+}
+```
+
+## License
+
+This project is licensed under the terms of the GNU General Public License v3.0.
+
+If you use the library please put a link to the [website](https://gvinciguerra.github.io/PGM-index) and cite the following paper:
+```tex
+@misc{FerraginaVinciguerra:2019,
+  Archiveprefix = {arXiv},
+  Author = {Paolo Ferragina and Giorgio Vinciguerra},
+  Day = {14},
+  Eprint = {1910.06169},
+  Month = {10},
+  Primaryclass = {cs.DS},
+  Title = {The PGM-index: a multicriteria, compressed and learned approach to data indexing},
+  Url = {https://arxiv.org/abs/1910.06169},
+  Year = {2019}}
+```