added break error to flag grids where sx = an odd number.

python/hit_return_sim.py

@@ -82,6 +82,8 @@ class HitReturnSim:
     px,py=g['pitch']    #pitch to next position in um (or 1 if scaled)
     nx,ny=g['count']    #total count of wells
     sx,sy=kwargs['ssz'] #section size (in wells)
+    if sx % 2 != 0:
+      raise ValueError(f"mode 6 and 7 requires even number x rows, got sx={sx}")
     try:
       tsx, tsy=kwargs['smv']  # time(in num of shots) to move to next section (horiz/vert)
     except KeyError as e:
@@ -90,7 +92,8 @@ class HitReturnSim:
     try:
       tsd=kwargs['sdelay']
     except KeyError as e:
-      tsd=sx*sy
+        tsd=sx*sy
+    
     tsd+=1-sx*sy  # sdl are shots to wait at position #(6)
 
     tx,ty=nx//sx,ny//sy #total sections
@@ -268,4 +271,4 @@ if __name__=='__main__':
   #dp=DebugPlot('/tmp/shapepath.npz');dp.plot_gather(mode=11);plt.show()
   #exit(0)
   #ssh_test()
-  ret=parse_args()
+  ret=parse_args()