[FIXED] Find the percentile of a value

Issue

I have an array of values like [1,2,3,4,5] and I need to find the percentile of each value. The output I am expecting is something like [0,25,50,75,100].

I searched for an API in numpy that could get the desired result and found np.percentile but it does the opposite. Given a percentile value, it will find a value using the input list as the distribution.

Is there an api or way to get this? Thanks

Solution

If your input can contain arbitrary numbers (e. g. [3, 7, 13, 20]) which are to be mapped to 0% – 100%, then you need to figure out the minimum number and the maximum number and stretch your values to 0 … 100:

values = [ 3, 7, 13, 20 ]
min_value = min(values)
max_value = max(values)
for value in values:
  fraction = float(value - min_value) / (max_value - min_value)
  percentage = fraction * 100
  print(value, percentage)

Or as a comprehension:

percentiles = [ float(value - min_value) / (max_value - min_value) * 100
                for value in values ]

This can also be sped up using numpy for large inputs:

import numpy as np

values = np.array([ 3, 7, 13, 20 ])
min_value = values.min()
max_value = values.max()
percentiles = (values - min_value) / (max_value - min_value) * 100

Answered By - Alfe