continuous regions in an boolean array

gistfile1.py

import numpy as np

def contiguous_regions(condition):
    """Finds contiguous True regions of the boolean array "condition". Returns
    three 1d arrays:  start indicies, stop indicies and lengths of contigous regions
    """

    d = np.diff(condition)
    idx, = d.nonzero() 
    idx += 1 # need to shift indices because of diff

    if condition[0]:
        # If the start of condition is True prepend a 0
        idx = np.r_[0, idx]

    if condition[-1]:
        # If the end of condition is True, append the length of the array
        idx = np.r_[idx, condition.size] # Edit

    starts = idx[0::2]
    stops = idx[1::2]
    lengths = stops - starts
    
    return starts, stops, lengths