CODEWITHSUNDEEP
pythonnormalization
Akshat Bhargava
Akshat Bhargava

Reputation: 61

spreading/dividing (0.0 to 1.0) by a single number or range (0,inf)

What I need is to divide/spread 0 to 1. according to single number which is more than 2. like number 5 will be divided like this

0.00  
0.25
0.50
0.75
1.00

5 values in a list

and my other question is what to do to get a sequence like this where middle number is 1 and first and last number is 0 , if number is 10.

0.00
0.25
0.50
0.75
1.00
1.00
0.75
0.50
0.25
0.00

10 item in list how to this in python via loop ?

Upvotes: 0

Views: 61

Answers (2)

NOhs
NOhs

Reputation: 2830

Evenly spaced numbers

From the numpy linspace documentation:

Return evenly spaced numbers over a specified interval.

Exactly what we need to solve your first problem.

Code example

import numpy as np

def spread(n):
    return np.linspace(0, 1, n)

Mirroring list

For the second question we can just reuse the array from the first question, invert it and append it. We just have to integer divide // your number by 2 (assuming it is divisible by 2) to get the number to pass to spread. You get a reverse version of a list/tuple/numpy array doing the following:

my_list[::-1]

Code examples

So your function would look something like:

import numpy as np

def updown(n):
    first_half = spread(n//2)
    return np.r_[first_half, first_half[::-1]]

You could also flip the array using np.flipud and instead of np.r_ you could use np.concatenate:

import numpy as np

def updown(n):
    first_half = spread(n//2)
    return np.concatenate((first_half, np.flipud(first_half)))

Or if you do not need arrays in the end you could do (the same as in a different answer):

import numpy as np

def spread(n):
    return list(np.linspace(0, 1, n))

def updown(n):
    first_half = spread(n//2)
    return first_half + first_half[::-1]

Upvotes: 2

hiro protagonist
hiro protagonist

Reputation: 46859

the first part is easy:

def spread(n):
    return tuple(i/(n-1) for i in range(n))

and with that you can create the second by concatenating the tuple from above with the reversed tuple:

def updown(n):
    tpl = spread(n//2)
    return tpl + tpl[::-1]

if n is odd updown(n) will be the same as updown(n-1)...

Upvotes: 1

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