# Multithreading of the multi-arg function

So here's an example from the reference:

```
sage: def f(N,M=10): return N*M
sage: inputs = [(tuple([]), {'N':3,'M':5}), (tuple([]), {'N':4,'M':5})]
sage: for a, val in sage.parallel.reference.parallel_iter(f, inputs):
: print a, val
:
((), {'M': 5, 'N': 4}) 20
((), {'M': 5, 'N': 3}) 15
```

I'd like to call in parallel scipy.misc.derivative - which has lots of args:

```
for i in range(-2, 2, 0.01):
scipy.misc.derivative(imagLogPROD00, i, dx = 0.001, args=(opts.myN, 3, DP))
```

So I'm doing it in the following way:

```
mesh = arange(-2, 2, 0.01)
inputs = [[(tuple([]), {'func':imagLogPROD00, 'x0':i, 'dx':0.001, 'args':(opts.myN, 3, DP)})] for i in mesh]
for a, val in sage.parallel.reference.parallel_iter(scipy.misc.derivative, inputs):
print a, val
```

and I get error at parallel_iter:

```
ValueError: need more than 1 value to unpack
```

So ah... what could that be?