Bugfix: Add missing scaling to accumulated error (#763)

With MRI-HTol adaptivity, added missing scaling to accumulated
error and remove upper limit on rtol factor

---------

Co-authored-by: David Gardner <gardner48@llnl.gov>

Author: drreynolds

CHANGELOG.md

@@ -23,6 +23,11 @@ in any order.
 
 ### Bug Fixes
 
+Fixed a bug in how MRIStep interacts with an MRIHTol SUNAdaptController object
+(the previous version essentially just reverted to a decoupled multirate
+controller). Removed the upper limit on `inner_max_tolfac` in
+`SUNAdaptController_SetParams_MRIHTol`. 
+
 The shared library version numbers for the oneMKL dense linear solver and
 matrix as well as the PETSc SNES nonlinear solver have been corrected.
 

doc/shared/RecentChanges.rst

@@ -21,6 +21,11 @@ method after :c:func:`KINInit`. Additionally, :c:func:`KINSetMAA` and
 
 **Bug Fixes**
 
+Fixed a bug in how MRIStep interacts with an MRIHTol SUNAdaptController object
+(the previous version essentially just reverted to a decoupled multirate
+controller). Removed the upper limit on `inner_max_tolfac` in
+:c:func:`SUNAdaptController_SetParams_MRIHTol`. 
+
 The shared library version numbers for the oneMKL dense linear solver and
 matrix as well as the PETSc SNES nonlinear solver have been corrected.
 

doc/shared/sunadaptcontroller/SUNAdaptController_MRIHTol.rst

@@ -153,9 +153,14 @@ also provides the following additional user-callable routines:
    :param C: the SUNAdaptController_MRIHTol object.
    :param inner_max_relch: the parameter :math:`relch_{\text{max}}` (must be :math:`\ge 1`).
    :param inner_min_tolfac: the parameter :math:`\text{tolfac}_{min}` (must be :math:`> 0`).
-   :param inner_max_tolfac: the parameter :math:`\text{tolfac}_{max}` (must be :math:`> 0` and :math:`\le 1`).
+   :param inner_max_tolfac: the parameter :math:`\text{tolfac}_{max}` (must be :math:`> 0`).
 
    :returns: :c:type:`SUNErrCode` indicating success or failure.
+   
+   .. versionchanged:: x.y.z
+   
+      Removed the requirement that ``inner_max_tolfac`` must be :math:`\le 1`
+   
 
    .. note::
 

src/arkode/arkode_mristep.c

@@ -3571,6 +3571,11 @@ int mriStep_StageERKFast(ARKodeMem ark_mem, ARKodeMRIStepMem step_mem,
                         __FILE__, "Unable to get accumulated error from the inner stepper");
         return (ARK_INNERSTEP_FAIL);
       }
+
+      /* scale the error estimate by 1/rtol to account for different inner/outer tolerances */
+      step_mem->inner_dsm /= ark_mem->reltol;
+      SUNLogInfo(ARK_LOGGER, "accumulated-fast-error", "inner_dsm = %e",
+                 step_mem->inner_dsm);
     }
   }
 

src/sunadaptcontroller/mrihtol/sunadaptcontroller_mrihtol.c

@@ -236,8 +236,7 @@ SUNErrCode SUNAdaptController_SetParams_MRIHTol(SUNAdaptController C,
     MRIHTOL_INNER_MIN_TOLFAC(C) = INNER_MIN_TOLFAC;
   }
   else { MRIHTOL_INNER_MIN_TOLFAC(C) = inner_min_tolfac; }
-  if ((inner_max_tolfac <= SUN_RCONST(0.0)) ||
-      (inner_max_tolfac > SUN_RCONST(1.0)))
+  if (inner_max_tolfac <= SUN_RCONST(0.0))
   {
     MRIHTOL_INNER_MAX_TOLFAC(C) = INNER_MAX_TOLFAC;
   }