ProbabilityCurve and ProbabilityMap

class openquake.hazardlib.probability_map.ProbabilityCurve(array)

This class is a small wrapper over an array of PoEs associated to a set of intensity measure types and levels. It provides a few operators, including the complement operator ~

~p = 1 - p

and the inclusive or operator |

p = p1 | p2 = ~(~p1 * ~p2)

Such operators are implemented efficiently at the numpy level, by dispatching on the underlying array.

Here is an example of use:

>>> poe = ProbabilityCurve(numpy.array([0.1, 0.2, 0.3, 0, 0]))
>>> ~(poe | poe) * .5
<ProbabilityCurve
[ 0.405  0.32   0.245  0.5    0.5  ]>

class openquake.hazardlib.probability_map.ProbabilityMap

A dictionary site_id -> ProbabilityCurve. It defines the complement operator ~, performing the complement on each curve

~p = 1 - p

and the “inclusive or” operator |:

m = m1 | m2 = {sid: m1[sid] | m2[sid] for sid in all_sids}

Such operators are implemented efficiently at the numpy level, by dispatching on the underlying array. Moreover there is a classmethod .build(num_levels, num_gsims, sids, initvalue) to build initialized instances of ProbabilityMap.

classmethod build(num_levels, num_gsims, sids, initvalue=0.0)

Parameters:

• num_levels – the total number of intensity measure levels
• num_gsims – the number of GSIMs
• sids – a set of site indices
• initvalue – the initial value of the probability (default 0)

Returns:

a ProbabilityMap dictionary

extract(gsim_idx)

Extracts a component of the underlying ProbabilityCurves, specified by the index gsim_idx.