Test to check if my time series is constant for a long period of time

Question

How can I measure, if my time series is not changing with time, that is the value is constant for a very long period of time(not looking for stationarity test)

Answer 1

I don't know what exactly would fit your needs but here are some things I can think of are -

1. Just Plot it if it's small enough to identify regions of constant value
2. Write a small piece of code which finds subarrays with same value being repeated for a certain number of times if you want the value to be absolutely constant, alternatively you can add a tolerance so that values within a +- range are accepted

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