增加注释

rspower/lib/make_jac.txt

@@ -16,6 +16,8 @@ fn make_jac(baseMVA, bus, branch, gen) {
     on_k = get_multi(on, k);
     gen_vg = get_multi(slice(gen, [0], [VG-1,VG]), on_k);
     V = set(V, index, gen_vg ./ abs(voltage_g) .* voltage_g);
+
+    // build Jacobian
     dsbus_dv = dSbus_dV(Ybus, V, 0);
     return dsbus_dv;
 }
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