>>> array = [1,4,2,-2,-9,10,2,12,2,-4,-4,-4,-4,2,6,7]
>>> index = 0
>>> peak = array[0]
>>> output = []
>>>
>>> for x in range(1, len(array)):
...     if peak < 0 and array[x] < peak:
...         peak = array[x]
...         index = x
...     if peak >= 0  and array[x] > peak:
...         peak = array[x]
...         index = x
...     else:
...         output.append((index, peak))
...         peak = array[x]
...         index = x
...
>>> output
[(1, 4), (2, 2), (4, -9), (4, -9), (5, 10), (7, 12), (8, 2), (9, -4), (10, -4), (11, -4), (12, -4)]
>>>
>>>
>>> # Simplifies to:
>>>
>>> array = [1,4,2,-2,-9,10,2,12,2,-4,-4,-4,-4,2,6,7]
>>> index = 0
>>> peak = array[0]
>>> output = []
>>>
>>> for x in range(1, len(array)):
...     if peak < 0 or peak >= array[x]:
...         output.append((index, peak))
...     peak = array[x]
...     index = x
...
>>> output
[(1, 4), (2, 2), (3, -2), (4, -9), (5, 10), (7, 12), (8, 2), (9, -4), (10, -4), (11, -4), (12, -4)]