Running maximum of numpy array values

Question

I need a fast way to keep a running maximum of a numpy array. For example, if my array was:

x = numpy.array([11,12,13,20,19,18,17,18,23,21])

<

Answer 1

As suggested, there is scipy.maximum.accumulate:

In [9]: x
Out[9]: [1, 3, 2, 5, 4]

In [10]: scipy.maximum.accumulate(x)
Out[10]: array([1, 3, 3, 5, 5])