1 files changed, 35 insertions, 0 deletions
diff --git a/lib/net_conductivity.c b/lib/net_conductivity.c
new file mode 100644
index 0000000..e9325bb
--- /dev/null
+++ b/lib/net_conductivity.c
@@ -0,0 +1,35 @@
+
+#include "fracture.h"
+
+double net_conductivity(const net_t *net, const double *voltages) {
+	if (net->voltage_bound) {
+		// the voltage drop across the network is fixed to one with voltage
+		// boundary conditions, so the conductivity is the total current flowing
+		double tot_cur = 0;
+		for (uint_t i = 0; i < net->graph->num_spanning_edges; i++) {
+			uint_t e = net->graph->spanning_edges[i];
+
+			if (!net->fuses[e]) {
+				uint_t v1, v2, s1, s2;
+				double v1y, v2y;
+
+				v1 = net->graph->ev[2 * e];
+				v2 = net->graph->ev[2 * e + 1];
+
+				v1y = net->graph->vx[2 * v1 + 1];
+				v2y = net->graph->vx[2 * v2 + 1];
+
+				s1 = v1y < v2y ? v1 : v2;
+				s2 = v1y < v2y ? v2 : v1;
+
+				tot_cur += voltages[s1] - voltages[s2];
+			}
+		}
+
+		return fabs(tot_cur);
+	} else {
+		// the current across the network is fixed to one with current boundary
+		// conditions, so the conductivity is the inverse of the total voltage drop
+		return 1 / fabs(voltages[net->graph->nv] - voltages[net->graph->nv + 1]);
+	}
+}