From 018f9dd33264cba4abe8dbd5d1cfbc060e30eb11 Mon Sep 17 00:00:00 2001
From: Joshua Lambert <joshua.lambert@lshtm.ac.uk>
Date: Fri, 23 Feb 2024 15:58:02 +0000
Subject: [PATCH] optimise .sim_network_bp by moving contact distribution
 density outside loop

---
 R/sim_network_bp.R | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/R/sim_network_bp.R b/R/sim_network_bp.R
index 96bf83da..83fea9fa 100644
--- a/R/sim_network_bp.R
+++ b/R/sim_network_bp.R
@@ -51,17 +51,17 @@
   ancestor_idx <- 1L
   prev_ancestors <- 1L
 
+  if (config$network == "adjusted") {
+    # sample contact distribution (excess degree distribution)
+    q <- contact_distribution(0:1e4 + 1) * (0:1e4 + 1)
+    q <- q / sum(q)
+  } else {
+    q <- contact_distribution(0:1e4)
+  }
+
   # run loop until no more individuals are sampled
   while (next_gen_size > 0) {
-    if (config$network == "adjusted") {
-      # sample contact distribution (excess degree distribution)
-      q <- contact_distribution(0:1e4 + 1) * (0:1e4 + 1)
-      q <- q / sum(q)
-    } else {
-      q <- contact_distribution(0:1e4)
-    }
     contacts <- sample(0:1e4, size = next_gen_size, replace = TRUE, prob = q)
-
     # add contacts if sampled
     if (sum(contacts) > 0L) {
       chain_size <- chain_size + sum(contacts)