Boolean evaluation of an array

[ryankeedy]

Python doesn't care for the way the validity of a value is being evaluated:

Traceback (most recent call last):
File "pypiv_test.py", line 43, in
u, v, mask = openpiv.validation.global_val( u, v, (-10, 200), (-30, 30) )
File "/usr/local/lib/python2.6/dist-packages/openpiv/validation.py", line 65, in global_val
ind = u < u_thresholds[0] or u > u_thresholds[1] or v < v_thresholds[0] or v > v_thresholds[1]
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

It seems that because u and v are arrays, it is not interested in evaluating it.

[alexlib]

Thanks for pointing this out. It's indeed a bug. I replaced the line in validation.py that uses 'or' conditioning by np.logical_or and it works now.
the tutorial_part1.zip should be also updated