Generate random array of floats between a range

Question

I haven t been able to find a function to generate an array of random floats of a given length between a certain range   I ve looked at Random sampling but no function seems to do what I need   random uniform comes close but it only returns a single element  not a specific number   This is what I m after   ran floats   some function low 0 5  high 13 3  size 50    which would return an array of 50 random non-unique floats  ie  repetitions are allowed  uniformly distributed in the range  0 5  13 3    Is there such a function

User · Answer

The for loop in list comprehension takes time and makes it slow. It is better to use numpy parameters (low, high, size, ..etc)

import numpy as np
import time
rang = 10000
tic = time.time()
for i in range(rang):
    sampl = np.random.uniform(low=0, high=2, size=(182))
print("it took: ", time.time() - tic)

tic = time.time()
for i in range(rang):
    ran_floats = [np.random.uniform(0,2) for _ in range(182)]
print("it took: ", time.time() - tic)

sample output:

('it took: ', 0.06406784057617188)

('it took: ', 1.7253198623657227)

User · Answer

np random uniform fits your use case   sampl   np random uniform low 0 5  high 13 3  size  50      Update Oct 2019   While the syntax is still supported  it looks like the API changed with NumPy 1 17 to support greater control over the random number generator  Going forward the API has changed and you should look at https   docs scipy org doc numpy reference random generated numpy random Generator uniform html  The enhancement proposal is here  https   numpy org neps nep-0019-rng-policy html

User · Answer

np random random sample size  will generate random floats in the half-open interval  0 0  1 0

User · Answer

There may already be a function to do what you re looking for  but I don t know about it  yet    In the meantime  I would suggess using   ran floats   numpy random rand 50     13 3-0 5    0 5   This will produce an array of shape  50   with a uniform distribution between 0 5 and 13 3   You could also define a function   def random uniform range shape  1   low 0 high 1               Random uniform range      Produces a random uniform distribution of specified shape  with arbitrary max and     min values  Default shape is  1   and default range is  0 1               return numpy random rand shape     high - min    min   EDIT  Hmm  yeah  so I missed it  there is numpy random uniform   with the same exact call you want  Try import numpy  help numpy random uniform  for more information

User · Answer

Why not to combine random uniform with a list comprehension    gt  gt  gt  def random floats low  high  size          return  random uniform low  high  for   in xrange size         gt  gt  gt  random floats 0 5  2 8  5   2 366910411506704  1 878800401620107  1 0145196974227986  2 332600336488709  1 945869474662082

User · Answer

Alternatively you could use SciPy  from scipy import stats stats uniform 0 5  13 3  rvs 50    and for the record to sample integers it s  stats randint 10  20  rvs 50

User · Answer

Why not use a list comprehension   In Python 2  ran floats    random uniform low high  for   in xrange size     In Python 3  range works like xrange ref   ran floats    random uniform low high  for   in range size

User · Answer

This is the simplest way  np random uniform start stop  rows columns

[python] Generate random array of floats between a range

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