DocScoDoc/app/scodoc/listhistogram.py

32 lines
789 B
Python

import math
def ListHistogram(L, nbins, minmax=None, normalize=None):
"""Compute histogram of a list.
Does not use Numeric or numarray.
H[i] is the number of elements from L
such that bins[i] <= L[i] < bins[i+1]
"""
n = len(L)
if minmax is None:
xmin = min(L)
xmax = max(L)
else:
xmin, xmax = minmax
# clip data
for i in range(n):
if L[i] < xmin:
L[i] = xmin
if L[i] > xmax:
L[i] = xmax
bin_width = (xmax - xmin) / float(nbins - 1)
H = [0] * nbins
for i in range(n):
idx = int(math.floor((L[i] - xmin) / bin_width))
H[idx] += 1
bins = []
for i in range(nbins):
bins.append(xmin + bin_width * i)
return bins, H