CODEWITHSUNDEEP
pythonstringdictionaryhistogram
Joel
Joel

Reputation: 175

Python histogram from dictionary

I have a dictionary that looks liks this:

dict = {1092267: '0.187', 524292: '-0.350', 524293: '0.029', 524294: '0.216'}

So there is an id, and then a value that's inside a string (the real dictionary contains 10 000 of these id's). I want to make a histogram with on the x axis the absolute values of the values inside those strings from lets say 0-0.1, 0.1-0.2, 0.2-0.3 etc all the way to 0.9-1.0. The y axis should count the amount of occurences of the values within these ranges of 0-0.1 etc. How do I do this???

Upvotes: 2

Views: 3412

Answers (2)

VHarisop
VHarisop

Reputation: 2826

You can use numpy.histogram to create the histogram's bins. First of all, get the absolute values of all the dictionary's values (since ids are irrelevant). 

dict_values = [abs(float(i)) for i in dict.values()]

Then, use numpy.histogram specifying the range of the values explicitly.

import numpy as np
hist = np.histogram(dict_values, range=(0.0,1.0))

Upvotes: 3

pbc1303
pbc1303

Reputation: 152

Without using numpy.histogram, you can try:

test = {1092267: '0.187', 524292: '-0.350', 524293: '0.029', 524294: '0.216'}

intervals = [(-2, 0.1), (0.1, 0.2), (0.2, 0.3), (0.3, 0.4)]
count = []

for inf, sup in intervals:
    count.append(len([x for x in test.values() if inf < float(x) < sup]))

Then, count, which is the histogram, will have [2, 1, 1, 0]. This way you can specify arbitrary ranges to define the bins. If you want to plot it, you can use matplotlib (example here).

1: http://matplotlib.org/1.3.0/examples/pylab_examples/histogram_demo_extended.html

Upvotes: 0

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