Can we predict the next number in a sequence, based on a single column of numbers?

user_5212614 0
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I am trying to find a way to predict the next number in a sequence of numbers. Normally I would go use liner regression for this, but as you can see, there are dates and one single column of data. There is no dependent variable, there is only an independent variable (Loans). Is there a simple way to predict what the next number could be, or maybe a range of two numbers, based on a know sequence of numbers? Also, is there a way to get the probability of the outcome, like 90% or 95% confident?

Here is my data.

Account                            Loans
2019 Aug                           393.3
2020 Feb                           383.2
2020 Mar                           455.4
2020 Apr                           542.0
2020 May                           510.0
2020 Jun                           483.5
2020 Jul                           465.5
2020 Aug                           448.2
Aug 12                             451.1
Aug 19                             447.5
Aug 26                             442.3
Sep 02                             444.7

Ultimately I would like to see something like: 443 to 445 with 95% confidence. Is that possible?

prediction python-3.x python
2 Answers

Solution

Option 1 - rolling average

Take the average of the last n values (a). Subtract a from last number (l) as (s). The end result should be l-s or l+s.

Example


def predict(arr, n):
  l = arr[-1]
  a = sum(arr[:n]) / n
  s = abs(a - l)
  lower_bounds = l - s
  upper_bounds = l + s
  
  return (upper_bounds, lower_bounds)

Option 2 - exponential smoothing

Consider using exponential smoothing from stats models

Example

from statsmodels.tsa.api import SimpleExpSmoothing

def predict(arr, sl)
    return SimpleExpSmoothing(arr).fit(smoothing_level=sl).fitted_values

References

statsmodels (Simple Exponential Smoothing): https://www.statsmodels.org/stable/examples/notebooks/generated/exponential_smoothing.html

Python Simple Exponential Smoothing

NumPy version of "Exponential weighted moving average", equivalent to pandas.ewm().mean()

calculate exponential moving average in python

user_8068760

First, you need to do some preprocessing to convert your independent variable to some number scale. Maybe the number of days form 1st Aug 2019. Then you can do the regression.

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