binstore 1.7.1

Module to implement C extension Bins class for bin-based storage of items

Description

binstore module with Bins C extension to implement storage of items based on value-based binning where binned value determines ordinal index into array where item is stored. Supports item assignment and slice operations.

Members

• min - float, minimum value
• max - float, maximum value
• width - float, bin width
• n_bins - int, number of bins = int((max - min) / width) + 1

Methods

• bin(value) - perform binning operation on value and returns corresponding bin ordinal value 0 <= n <= n_bins - 1
• put(value, item) - puts item into bin n = bin(value) and returns n
• get(value) - gets item from bin n = bin(value) and returns as tuple of (item, n)
• items() - returns items in bins as dict with left bin edge as key, item in bin as value

When performing binning:

1. if value is <= min, bin(value) = 0
2. if value is >= max, bin(value) = n_bins - 1
3. if value is >= half the distance between left edge of bin n and left edge of bin n+1, then corresponding bin(value) = n+1, otherwise bin(value) = n. e.g., for min = 0.0, max = 1.0, width = 0.01, bin(0.106) = 11, bin(0.103) = 10.

Example:

>>>b = Bins(min=0.0, max=1.0, width=0.01) >>>for i in range(50): >>> b.put(i/100, {'i': i}) 0 1 2 . 49 >>>b.get(0.005) ({'i': 1}, 1) >>>b.get(0.000) ({'i': 0}, 0) >>>b.get(0.004) ({'i': 0}, 0) >>>b.get(0.103) ({'i': 10}, 10) >>>b.get(0.106) ({'i': 11}, 11) >>>b.put(0.106, {'foo': 'bar'}) 11 >>>b[11] {'foo': 'bar'} >>>b[11] = {'bar': 'foo'} >>>b[11] {'bar': 'foo'}