NumPy | bincount method
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Numpy's bincount(~)
method computes the bin count (i.e. the number of values that fall in an interval) given an array of values. By default, the interval size of each bin is one, and so the number of bins is dependent on the range of the input values.
Parameters
1. a
| array-like
The input array.
2. weights
| array-like
| optional
An array containing the weights placed on each of the input values. If a value falls in a particular bin, instead of incrementing the count by one, we increment by the corresponding weight. The shape must be the same as that of a
. By default, the weights are all one.
3. minlength
| int
| optional
The minimum number of bins.
Return value
A Numpy array containing the bin counts.
Examples
Basic usage
my_hist = np.bincount([1,3,6,6,10])my_hist
array([0, 1, 0, 1, 0, 0, 2, 0, 0, 0, 1])
Specifying weights
my_hist = np.bincount([1,3,6,6,10], weights=[2,3,4,5,6])my_hist
array([0., 2., 0., 3., 0., 0., 9., 0., 0., 0., 6.])
The reason why we get a 9 there is that the two 6s we have in the input array obviously fall in the same bin, and since their respective weights are 4 and 5, we end up with a total bin count of 4+5=9
.
Specifying the min length
my_hist = np.bincount([1,3,6,6,10], minlength=20)my_hist
array([0, 1, 0, 1, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0])
Notice bin size remained as one - the minlength just widened the global range.