1 files changed, 16 insertions, 5 deletions

diff --git a/lib/src/graph.cpp b/lib/src/graph.cpp
index 526ffeb..8aa8877 100644
--- a/lib/src/graph.cpp
+++ b/lib/src/graph.cpp
@@ -141,27 +141,38 @@ unsigned get_triangle_signature(unsigned j1, unsigned j2, unsigned j3) {
 }
 
 graph::graph(double Lx, double Ly, std::mt19937& rng) {
-  L = {Lx, Ly};
-
   // randomly choose N to be floor(Lx * Ly / 2) or ceil(Lx * Ly / 2) with
   // probability proportional to the distance from each
   std::uniform_real_distribution<double> d(0.0, 1.0);
   unsigned N = round(Lx * Ly / 2 + d(rng) - 0.5);
 
-  unsigned nv = N;
+  L = {Lx, Ly};
+
+  this->helper(N, rng);
+}
+
+graph::graph(unsigned n, double a, std::mt19937& rng) {
+  L = {2 * n * a, 2 * n / a};
+
+  this->helper(n, rng);
+}
+
+void graph::helper(unsigned n, std::mt19937& rng) {
+  std::uniform_real_distribution<double> d(0.0, 1.0);
+  unsigned nv = n;
   vertices.resize(nv);
 
   // the coordinates of the lattice, from which a delaunay triangulation
   // and corresponding voronoi tessellation will be built. Everyone is in the
   // rectangle (0, 0) (Lx, Ly)
   for (vertex &v : vertices) {
-    v = {{Lx * d(rng), Ly * d(rng)}};
+    v = {{L.x * d(rng), L.y * d(rng)}};
   }
 
   // set up the voronoi objects
   jcv_diagram diagram;
   memset(&diagram, 0, sizeof(jcv_diagram));
-  jcv_rect bounds = {{-Lx, -Ly}, {2 * Lx, 2 * Ly}};
+  jcv_rect bounds = {{-L.x, -L.y}, {2 * L.x, 2 * L.y}};
   std::vector<jcv_point> points(9 * nv);
 
   for (unsigned i = 0; i < nv; i++) {