Generate 40 Gaussian random integers in the range 50-100

Python Help
1

How to generate 40 Gaussian random integers in the range 50-100?

Regards,
HY

2

Hi,

You can’t. Gaussian random numbers are in the infinite range -∞ to +∞,
and they aren’t integers.

Best you can do is get approximately or nearly Gaussian
numbers that are limited to the range 50-100.

First, you have to decide what the mean and stardard deviation of the
numbers should be. Lets say you want a mean of exactly half way, 75, and
a standard deviation of 10. That means that:

  • approximately 68% of your numbers will be between 65 and 85;

  • approximately 95% of your numbers will be between 55 and 95;

  • approximately 99.7% of your numbers will be between 45 and 105;

  • approximately 99.994% of your numbers will be between 35 and 115;

and so on. So the first step is to generate Gaussian random numbers:

>>> from random import gauss
>>> values = [gauss(75, 10) for i in range(10)]
>>> print(values)
[61.23596221286689, 76.60587129908207, 51.6560837542098, 
57.99047892069517, 70.08685500419143, 76.62651107343562, 
66.4317029607017, 83.96234038824969, 67.58214182339955, 
80.13707807636534]

The second step: you have floats, not integers. So let’s round them off:

>>> values = [int(round(x)) for x in values]
>>> print(values)
[61, 77, 52, 58, 70, 77, 66, 84, 68, 80]

Nice! But it was just luck that every one of those numbers was between
50 and 100. If I generated a million numbers instead of 10, I would
probably have about 1% (ten thousand) outside of that range.

So the third step is to filter out anything outside of that range:

values = [x for x in values if 50 <= x <= 100]

We can put all of this into a single function:

def my_gauss():
    # Almost Gaussian random integers between 50 and 100
    x = -1
    while not 50 <= x <= 100:
        x = int(round(gauss(75, 10)))
    return x

values = [my_gauss() for x in range(10)]
3

Thank you very much for your wonderful solution.

Regards,
HY