1 files changed, 54 insertions, 7 deletions

diff --git a/src/RK45.c b/src/RK45.c
index f92159a..3ca2456 100644
--- a/src/RK45.c
+++ b/src/RK45.c
@@ -67,11 +67,9 @@ void MoL_RK45Add(CCTK_ARGUMENTS)
   DECLARE_CCTK_ARGUMENTS;
   DECLARE_CCTK_PARAMETERS;
     
-  cGroupDynamicData arraydata;
-  CCTK_INT groupindex, ierr;
-  CCTK_INT arraytotalsize, arraydim;
+  CCTK_INT arraydim;
 
-  CCTK_INT index, var, scratchstep, alphaindex, scratchindex;
+  CCTK_INT index, var, scratchstep;
   CCTK_INT totalsize;
 
   CCTK_REAL       * restrict UpdateVar;
@@ -84,7 +82,8 @@ void MoL_RK45Add(CCTK_ARGUMENTS)
 
   CCTK_REAL beta, gamma, gamma_error;
 
-  static const CCTK_REAL beta_array[5][5] = {
+  /* Fehlberg coefficients */
+  static const CCTK_REAL beta_array_F[5][5] = {
     { 0.25,    0.0,     0.0, 0.0, 0.0 },
     { 0.09375, 0.28125, 0.0, 0.0, 0.0 },
     { 0.879380974055530268548020027310, -3.27719617660446062812926718252, 3.32089212562585343650432407829, 0.0, 0.0 },
@@ -92,7 +91,7 @@ void MoL_RK45Add(CCTK_ARGUMENTS)
     { -0.296296296296296296296296296296, 2.0, -1.38167641325536062378167641326, 0.452972709551656920077972709552, -0.275 }
   };
 
-  static const CCTK_REAL gamma_array[6] = 
+  static const CCTK_REAL gamma_array_F[6] = 
     { 0.118518518518518518518518518519, 
       0.0, 
       0.518986354775828460038986354776, 
@@ -101,7 +100,7 @@ void MoL_RK45Add(CCTK_ARGUMENTS)
       0.0363636363636363636363636363636
     };
 
-  static const CCTK_REAL gammastar_array[6] = 
+  static const CCTK_REAL gammastar_array_F[6] = 
     { 0.115740740740740740740740740741, 
       0.0, 
       0.548927875243664717348927875244, 
@@ -110,6 +109,54 @@ void MoL_RK45Add(CCTK_ARGUMENTS)
       0.0 
     };
 
+  /* Cash-Karp coefficients */
+  static const CCTK_REAL beta_array_CK[5][5] = {
+    { 1.0/5.0,        0.0,         0.0,           0.0,              0.0,      },
+    { 3.0/40.0,       9.0/40.0,    0.0,           0.0,              0.0,      },
+    { 3.0/10.0,       -9.0/10.0,   6.0/5.0,       0.0,              0.0,      },
+    { -11.0/54.0,     5.0/2.0,     -70.0/27.0,    35.0/27.0,        0.0,      },
+    { 1631.0/55296.0, 175.0/512.0, 575.0/13824.0, 44275.0/110592.0, 253.0/4096.0, },
+  };
+
+  static const CCTK_REAL gamma_array_CK[6] = {
+    37.0/378.0,
+    0.0,
+    250.0/621.0,
+    125.0/594.0,
+    0.0,
+    512.0/1771.0,
+  };
+
+  static const CCTK_REAL gammastar_array_CK[6] = {
+    2825.0/27648.0,
+    0.0,
+    18575.0/48384.0,
+    13525.0/55296.0,
+    277.0/14336.0,
+    1.0/4.0,
+  };
+
+  const CCTK_REAL (* restrict beta_array)[5];
+  const CCTK_REAL * restrict gamma_array;
+  const CCTK_REAL * restrict gammastar_array;
+
+  if (CCTK_EQUALS(ODE_Method, "RK45"))
+  {
+    beta_array = beta_array_F;
+    gamma_array = gamma_array_F;
+    gammastar_array = gammastar_array_F;
+  }
+  else if (CCTK_EQUALS(ODE_Method, "RK45CK"))
+  {
+    beta_array = beta_array_CK;
+    gamma_array = gamma_array_CK;
+    gammastar_array = gammastar_array_CK;
+  }
+  else
+  {
+    CCTK_WARN (0, "internal error");
+  }
+
   totalsize = 1;
   for (arraydim = 0; arraydim < cctk_dim; arraydim++)
   {