[Math] Formula for Average Percentage Increase/Decrease from chronological data range.

averagedata analysis

Let's say I have the following data:

$$1,2,3,1,4,0,6,4,3,2,46,7,5,7$$

I'd like to get a percentage based off some sort of average change of the data (in the order) to get an idea of what % the data appears to be increasing/decreasing on average.

The data above is obviously increasing from start to finish (with a few random changes). But what is the average increase in a percentage format?

My first thought was to take the difference between each consecutive number pair (ie: $2-1 = 1, 3-2 = 1, 1-3 = -2,$ etc), then taking the averages of all these difference values. This might get what I want. But I was wondering if there was some more clever formulas that might do this better.

Cheers!

Best Answer

A good measure of this is check the highest increasing chain.

$100*$(No of elements in the highest increasing chain)$/$No of total elements is a good measure of percentage of increasing trend in a particular data.

By the largest increasing chain of the sequence $a_1,a_2,a_3,....a_n$, what I meant is a subsequence with largest cardinality which is increasing, that is a subsequence $a_{k_1},a_{k_2},....a_{k_m}$ such that $k_1<k_2<....<k_m$ and $a_{k_1}<a_{k_2},....<a_{k_m}$

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