Dynamically set NCC (= don't break with less than 4 chains)

src/BayesWaveModel.c

@@ -1024,7 +1024,8 @@ void initialize_bayescbc(struct bayesCBC *bayescbc, struct Data *data, struct Ch
     bayescbc->NP = bayescbc->NX+4;   // total number of entries in the full parameter arrays NX+4
     bayescbc->NS = 7;    // number of quasi-extrinsic parameters (alpha, sin(delta), psi, ellipticity, scale, phi0=2*phic, dt)
     bayescbc->NC = chain->NC;   // number of chains
-    bayescbc->NCC = 4;   // number of cold chains 
+    bayescbc->NCC = 1;          // number of cold chains in cbc burnin
+    if (bayescbc->NC > 1) bayescbc->NCC = (int) bayescbc->NC/2;   // number of cold chains in cbc burnin
     bayescbc->NH = 1000; // length of history
     bayescbc->NQ = 4;    // number of mass ratios in global proposal
     bayescbc->NM = 1000; // number of chirp masses in global proposal