read from file

Cargo.lock

@@ -33,7 +33,7 @@ dependencies = [
 
 [[package]]
 name = "graph_force"
-version = "0.1.3"
+version = "0.2.0"
 dependencies = [
  "pyo3",
  "rand",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "graph_force"
-version = "0.1.3"
+version = "0.2.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

README.md

@@ -9,6 +9,11 @@ pip install graph_force
 ```
 
 ## Usage
+
+The first parameter defines the number of nodes in graph.
+The second parameter is an iterable of edges, where each edge is a tuple of two integers representing the nodes it connects. Node ids start at 0. 
+
+
 ```python
 import graph_force
 
@@ -17,6 +22,9 @@ pos = graph_force.layout_from_edge_list(4, edges)
 ```
 
 ### Example with networkx
+
+This library does not have a function to consume a networkx graph directly, but it is easy to convert it to an edge list.
+
 ```python
 import networkx as nx
 import graph_force
@@ -34,6 +42,47 @@ pos = graph_force.layout_from_edge_list(len(G.nodes), edges, iter=1000)
 nx.draw(G, {n: pos[i] for n, i in mapping.items()}, node_size=2, width=0.1)
 ```
 
+### Example with edge file
+
+This methods can be used with large graphs, where the edge list does not fit into memory.
+
+Format of the file:
+- Little endian
+- 4 bytes: number of nodes(int)
+- 12 bytes: nodeA(int), nodeB(int), weight(float)
+
+```python
+import graph_force
+import struct
+
+with open("edges.bin", "rb") as f:
+    n = 10
+    f.write(struct.pack("i", n))
+    for x in range(n-1):
+        f.write(struct.pack("iif", x, x+1, 1))
+
+pos = graph_force.layout_from_edge_file("edges.bin", iter=50)
+```
+
+
+### Options
+
+`iter`, `threads` and `model` are optional parameters, supported by `layout_from_edge_list` and `layout_from_edge_file`.
+
+```python
+pos = graph_force.layout_from_edge_list(
+    number_of_nodes,
+    edges,
+    iter=500,  # number of iterations, default 500
+    threads=0,  # number of threads, default 0 (all available)
+    model="spring_model", # model to use, default "spring_model", other option is "networkx_model"
+)
+```
+#### Available models
+
+- `spring_model`: A simple spring model (my own implementation)
+- `networkx_model`: Reimplementation of the [spring model from networkx](https://networkx.org/documentation/stable/reference/generated/networkx.drawing.layout.spring_layout.html)
+
 ## Contributing
 
 - [Development](DEVELOPMENT.md)

src/lib.rs

@@ -1,6 +1,7 @@
 mod graph;
 mod model;
 mod networkx_model;
+mod reader;
 mod runner;
 mod spring_model;
 mod utils;
@@ -8,6 +9,32 @@ mod utils;
 use pyo3::exceptions;
 use pyo3::{prelude::*, types::PyIterator};
 
+fn pick_model(model: &str) -> Result<Box<dyn model::ForceModel + Send + Sync>, PyErr> {
+    match model {
+        "spring_model" => Ok(Box::new(spring_model::SimpleSpringModel::new(1.0))),
+        "networkx_model" => Ok(Box::new(networkx_model::NetworkXModel::new())),
+        _ => {
+            return Err(PyErr::new::<exceptions::PyValueError, _>(
+                "model must be either 'spring_model' or 'networkx_model'",
+            ))
+        }
+    }
+}
+
+#[pyfunction(file_path, "*", iter = 500, threads = 0, model = "\"spring_model\"")]
+fn layout_from_edge_file(
+    file_path: &str,
+    iter: usize,
+    threads: usize,
+    model: &str,
+) -> PyResult<Vec<(f32, f32)>> {
+    let (size, matrix) = reader::read_graph(file_path);
+    let model = pick_model(model)?;
+
+    let r = runner::Runner::new(iter, threads);
+    Ok(r.layout(size, matrix, model))
+}
+
 #[pyfunction(
     number_of_nodes,
     edges,
@@ -23,15 +50,7 @@ fn layout_from_edge_list(
     threads: usize,
     model: &str,
 ) -> PyResult<Vec<(f32, f32)>> {
-    let model: Box<dyn model::ForceModel + Send + Sync> = match model {
-        "spring_model" => Box::new(spring_model::SimpleSpringModel::new(1.0)),
-        "networkx_model" => Box::new(networkx_model::NetworkXModel::new()),
-        _ => {
-            return Err(PyErr::new::<exceptions::PyValueError, _>(
-                "model must be either 'spring_model' or 'networkx_model'",
-            ))
-        }
-    };
+    let model: Box<dyn model::ForceModel + Send + Sync> = pick_model(model)?;
 
     let mut edge_matrix = graph::new_edge_matrix(number_of_nodes);
     match edges.extract::<&PyIterator>() {
@@ -70,5 +89,6 @@ fn layout_from_edge_list(
 #[pymodule]
 fn graph_force(_py: Python, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(layout_from_edge_list, m)?)?;
+    m.add_function(wrap_pyfunction!(layout_from_edge_file, m)?)?;
     Ok(())
 }

src/networkx_model.rs

@@ -3,6 +3,7 @@ use crate::model::ForceModel;
 
 /**
  * Translation of the NetworkX spring_layout function.
+ * https://networkx.org/documentation/stable/reference/generated/networkx.drawing.layout.spring_layout.html
  */
 pub struct NetworkXModel {
     edges: EdgeMatrix,

src/reader.rs

@@ -1,3 +1,7 @@
+use std::{fs::File, io::Read};
+
+use crate::graph::{add_edge, new_edge_matrix, EdgeMatrix};
+
 /**
  * Read Graph data from file
  * Format:
@@ -5,22 +9,20 @@
  *  - 4 bytes: number of nodes(int)
  *  - 12 bytes: nodeA(int), nodeB(int), weight(float)
  */
-fn read_graph(file_name: &str) -> (usize, EdgeMatrix) {
+pub fn read_graph(file_name: &str) -> (usize, EdgeMatrix) {
     let mut file = File::open(file_name).expect("file not found");
     let mut size_buffer = [0; 4];
     file.read_exact(&mut size_buffer).expect("buffer overflow");
     let size = u32::from_le_bytes(size_buffer) as usize;
-    let matrix_ptr = connection_matrix(size);
+    let mut matrix = new_edge_matrix(size);
     {
-        let mut matrix = matrix_ptr.write().unwrap();
         let mut buffer = [0; 12];
         while file.read_exact(&mut buffer).is_ok() {
             let node_a = u32::from_le_bytes(buffer[0..4].try_into().unwrap()) as usize;
             let node_b = u32::from_le_bytes(buffer[4..8].try_into().unwrap()) as usize;
-            let weight = f32::from_le_bytes(buffer[8..12].try_into().unwrap());
-            matrix[node_a][node_b].weight = weight;
-            matrix[node_b][node_a].weight = weight;
+            let _weight = f32::from_le_bytes(buffer[8..12].try_into().unwrap());
+            add_edge(&mut matrix, node_a, node_b);
         }
     }
-    (size, matrix_ptr)
+    (size, matrix)
 }

tests/test_e2e.py

@@ -1,4 +1,5 @@
 import graph_force
+import struct
 
 def test_list_of_edges():
     edges = [(1, 2), (2, 3), (3, 4), (4, 5), (5, 6)]
@@ -28,3 +29,14 @@ def test_model_selection():
     pos = graph_force.layout_from_edge_list(7, edges, model='networkx_model')
     assert pos is not None
     assert len(pos) == 7
+
+def test_from_file():
+    with open("/tmp/edges.bin", "wb") as f:
+        n = 10
+        f.write(struct.pack("i", n))
+        for x in range(n-1):
+            f.write(struct.pack("iif", x, x+1, 1))
+
+    pos = graph_force.layout_from_edge_file('/tmp/edges.bin')
+    assert pos is not None
+    assert len(pos) == 10