(func)
| 67 | raise Exception("cannot form curl") |
| 68 | |
| 69 | def div(func): |
| 70 | if func.derivname == "div": |
| 71 | return func.Deriv() |
| 72 | try: |
| 73 | return func.Operator("div") |
| 74 | except: |
| 75 | pass |
| 76 | try: |
| 77 | return Trace(grad(func)) |
| 78 | except: |
| 79 | pass |
| 80 | #if func.derivname == "grad" and len(func.dims)==2: # should check for square |
| 81 | # return Trace(grad(func)) |
| 82 | raise Exception("cannot form div") |
| 83 | |
| 84 | |
| 85 | def ConstantCF(val): |