How to scale a numpy array from 0 to 1 with overshoot?

I am trying to scale a pandas or numpy array from 0 to a unknown max value with the defined number replaced with 1.

One solution I tried is just dividing the defined number I want by the array.

test = df['Temp'] / 33

plot

This method does not scale all the way from 0 and I'm stuck trying to figure out a better mathematical way of solving this.

Solution

First, transform the DataFrame to a numpy array

import numpy as np
T = np.array(df['Temp'])

Then scale it to a [0, 1] interval:

def scale(A):
    return (A-np.min(A))/(np.max(A) - np.min(A))

T_scaled = scale(T)

Then transform it to anywhere you want, e.g. to [55..100]

T2 = 55 + 45*T_scaled

I'm sure that this can be done within Pandas too (but I'm not familiar with it). Perhaps you might study Pandas df.apply()