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Averages/Arithmetic mean: Difference between revisions
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! dividing by the length of the column, which is the number of rows (SIZE of dimension 1)</lang>
=={{header|F_Sharp|F#}}==
The following computes the running mean using a tail-recursive approach. If we just sum all the values then divide by the number of values then we will suffer from overflow problems for large lists. See [http://en.wikipedia.org/wiki/Moving_average wikipedia] about the moving average computation.
let avg (a:float) (v:float) n =
a + (1. / ((float n) + 1.)) * (v - a)
let mean_series list =
let rec f a n list =
match list with
| [] -> a
| h :: t -> f (avg a (float h) n) (n + 1) t
f 0. 0 list
Checking this:
> mean_series [1; 8; 2; 8; 1; 7; 1; 8; 2; 7; 3; 6; 1; 8; 100] ;;
val it : float = 10.86666667
> mean_series [] ;;
val it : float = 0.0
=={{header|Groovy}}==
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