numpy.histogram(a, bins=10, range=None, normed=False, weights=None, density=None)[source]
Compute the histogram of a set of data.
Parameters: |
a : array_like Input data. The histogram is computed over the flattened array. bins : int or sequence of scalars, optional If range : (float, float), optional The lower and upper range of the bins. If not provided, range is simply normed : bool, optional This keyword is deprecated in Numpy 1.6 due to confusing/buggy behavior. It will be removed in Numpy 2.0. Use the density keyword instead. If False, the result will contain the number of samples in each bin. If True, the result is the value of the probability density function at the bin, normalized such that the integral over the range is 1. Note that this latter behavior is known to be buggy with unequal bin widths; use weights : array_like, optional An array of weights, of the same shape as density : bool, optional If False, the result will contain the number of samples in each bin. If True, the result is the value of the probability density function at the bin, normalized such that the integral over the range is 1. Note that the sum of the histogram values will not be equal to 1 unless bins of unity width are chosen; it is not a probability mass function. Overrides the |
---|---|
Returns: |
hist : array The values of the histogram. See bin_edges : array of dtype float Return the bin edges |
See also
All but the last (righthand-most) bin is half-open. In other words, if bins
is:
[1, 2, 3, 4]
then the first bin is [1, 2)
(including 1, but excluding 2) and the second [2, 3)
. The last bin, however, is [3, 4]
, which includes 4.
>>> np.histogram([1, 2, 1], bins=[0, 1, 2, 3]) (array([0, 2, 1]), array([0, 1, 2, 3])) >>> np.histogram(np.arange(4), bins=np.arange(5), density=True) (array([ 0.25, 0.25, 0.25, 0.25]), array([0, 1, 2, 3, 4])) >>> np.histogram([[1, 2, 1], [1, 0, 1]], bins=[0,1,2,3]) (array([1, 4, 1]), array([0, 1, 2, 3]))
>>> a = np.arange(5) >>> hist, bin_edges = np.histogram(a, density=True) >>> hist array([ 0.5, 0. , 0.5, 0. , 0. , 0.5, 0. , 0.5, 0. , 0.5]) >>> hist.sum() 2.4999999999999996 >>> np.sum(hist*np.diff(bin_edges)) 1.0
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https://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.histogram.html