no driving option

src/driving.c

@@ -15,3 +15,14 @@ _Complex double g_test(
   return 0.;
 }
 
+#define UNUSED(x) (void)(x)
+_Complex double g_zero(
+  int kx,
+  int ky
+){
+  // avoid unused variable warnings
+  UNUSED(kx);
+  UNUSED(ky);
+  return 0.;
+}
+

src/driving.h

@@ -3,6 +3,7 @@
 
 #include <complex.h>
 
+_Complex double g_zero( int kx, int ky);
 _Complex double g_test( int kx, int ky);
 
 #endif

src/main.c

@@ -22,7 +22,8 @@ int set_parameter(char* lhs, char* rhs, int* K1, int* K2, int* N1, int* N2, unsi
 #define COMMAND_ENSTROPHY 2
 #define COMMAND_QUIET 3
 
-#define DRIVING_TEST 1
+#define DRIVING_ZERO 1
+#define DRIVING_TEST 2
 
 
 int main (
@@ -55,12 +56,15 @@ int main (
   }
   // set driving force
   switch(driving){
+  case DRIVING_ZERO:
+    g=g_zero;
+    break;
   case DRIVING_TEST:
     g=g_test;
     break;
 
   default:
-    g=g_test;
+    g=g_zero;
     break;
   }
 
@@ -137,7 +141,10 @@ int read_args(
     }
     // driving force
     else if(flag==CP_FLAG_DRIVING){
-      if (strcmp(argv[i],"test")==0){
+      if (strcmp(argv[i],"zero")==0){
+	*driving_force=DRIVING_ZERO;
+      }
+      else if (strcmp(argv[i],"test")==0){
 	*driving_force=DRIVING_TEST;
       }
       else{

src/navier-stokes.c

@@ -30,6 +30,18 @@ int uk(
   ns_init_tmps(&u, &tmp1, &tmp2, &tmp3, &fft1, &fft2, &ifft, K1, K2, N1, N2, nthreads);
   ns_init_u(u, K1, K2);
 
+  // print column headers
+  printf("#    1:i                    2:t ");
+  t=3;
+  for(kx=-K1;kx<=K1;kx++){
+    for (ky=-K2;ky<=K2;ky++){
+      printf("   %6d:(%4d,%4d)r ",t,kx,ky);
+      t++;
+      printf("   %6d:(%4d,%4d)i ",t,kx,ky);
+      t++;
+    }
+  }
+
   // iterate
   for(t=0;t<nsteps;t++){
     ins_step(u, K1, K2, N1, N2, nu, delta, g, fft1, fft2, ifft, tmp1, tmp2, tmp3);