bypass steepness calcs when steepness == 1

SS_prelim.tpl

@@ -859,6 +859,11 @@
   echoinput << " MG_parms after check " << MGparm << endl;
   MGparm_use = value(MGparm);
 
+  if (SR_fxn == 3)
+  {
+    if (SRparm_PH(2) < 0 && SRparm(2) >= 0.999999) use_steepness = 0;
+  }
+
   echoinput << endl
             << " now check SRparm bounds and priors and do jitter if requested " << endl;
   for (i = 1; i <= N_SRparm3; i++)

SS_readcontrol_330.tpl

@@ -2191,6 +2191,7 @@
   ivector SRparm_PRtype(1,N_SRparm3)
   vector SRparm_CV(1,N_SRparm3)
   ivector SRparm_PH(1,N_SRparm3)
+  int use_steepness  //  0/1 to do full steepness calculations with Beverton-Holt; set to 0 if h = 1 and not estimated
 
  LOCAL_CALCS
       // clang-format on
@@ -5956,6 +5957,14 @@
       active_parm(active_count) = ParCount;
     }
   }
+
+  // flag to bypass steepness calculations
+  use_steepness = 1; // default
+  // following test will occur in preliminary calcs such that it will work even if values are read from ss3.par
+  // if (SR_fxn == 3)
+  // {
+  //  if (SRparm_PH(2) < 0 || SRparm(2) >= 0.999999) use_steepness = 0;
+  // }
 
   if (recdev_cycle > 0)
   {

SS_recruit.tpl

@@ -50,8 +50,15 @@ FUNCTION dvariable Spawn_Recr(const dvar_vector& SRparm_work, const prevariable&
     case 3: // Beverton-Holt
     {
       steepness = SRparm_work(2);
-      NewRecruits = (4. * steepness * Recr_virgin_use * SSB_curr_adj) /
+      if (use_steepness == 1)
+      {
+        NewRecruits = (4. * steepness * Recr_virgin_use * SSB_curr_adj) /
           (SSB_virgin_use * (1. - steepness) + (5. * steepness - 1.) * SSB_curr_adj);
+      }
+      else
+      {
+        NewRecruits = Recr_virgin_use;
+      }
       break;
     }
 
@@ -318,16 +325,22 @@ FUNCTION dvar_vector Equil_Spawn_Recr_Fxn(const dvar_vector& SRparm,
 
   //  SS3 previously used alternative formulation: R = A*S/(B+S)
   //  converting SS3 to align with WHAM
+      if (use_steepness == 1)
+      {
       alpha = 4.0 * steepness / (SSBpR_virgin_use * (1. - steepness));
       beta = (5.0 * steepness - 1.0) / ((1 - steepness) * SSB_virgin_use);
-      // " h " << steepness << " derive "  << alpha * SSBpR_virgin / (4. + alpha * SSBpR_virgin) << " " << endl;
-      // " R0 " << Recr_virgin_use << " derive "  << 1. / beta * (alpha - 1./SSBpR_virgin) << endl;
 //      report5 <<" SSB_unf "<<SSB_virgin_use<<" SSBpR_unf "<<SSBpR_virgin<<" steep: "<<steepness<<" R0: "<<Recr_virgin_use << endl;
 //      report5 <<" derive_alpha "<<alpha<<" derive_beta "<<beta << endl;
 //      report5 << " deriv_h: " << alpha * SSBpR_virgin / (4. + alpha * SSBpR_virgin) << " derive_R0: " << 1. / beta * (alpha - (1. / SSBpR_virgin))<<endl;
       B_equil = (alpha * SSBpR_current - 1.0) / beta;
       B_equil = posfun(B_equil, 0.0001, temp);
       R_equil = alpha * B_equil / (1.0 + beta * B_equil);
+      }
+      else
+      {
+        R_equil = Recr_virgin_use;
+        B_equil = Recr_virgin_use * SSBpR_current;
+      }
 //      report5 << "SPR_input: " << SSBpR_current << " B_equil: " << B_equil << " R_equil: "<<R_equil << endl<<endl;
 
       break;