{{ transformations:SlidingAggregationAction.png}}
====== SLIDING AGGREGATION ======
Category: Transform / Advanced \\

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=====Description=====
This action calculates an aggregate, such as //average//, of N sliding values.  Available aggregations are: Average, Sum, Min, Max, Count Distinct.

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=====Use cases=====
This action can be used for adding smoothed trendlines to charts.

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=====Action settings=====
^Setting^Description^
|New column|Enter the name of the column that will contain the aggregated values.|
|Target column|Select the name of the column containing the values to be aggregated.|
|Aggregation mode|Select the aggregation method to be used on the values in the Target column.  Options: //Average//, //Sum//, //Min//, //Max//, or //Count Distinct//.|
|Window size<sup>*</sup>|Enter the number of consecutive rows to be included in the calculation.|
|Offset to|Select whether the calculated values in the //New column// will align with the top ("start") of the window, or the bottom ("end").  Options: //Window start// or //Window end//.|
|In groups|Check this "on" and select one or more columns to group the aggregated results in.|
<sup>*</sup> Setting can be specified using a [[:parameters|parameter]].\\

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=====Remarks=====
The //Window size// determines how many rows' values are included within each calculation.  A //Window size// of "4" includes 4 consecutive rows.  The //Offset to// selection determines whether the output value aligns with the top/start or bottom/end of the current window.

If there aren't enough rows within the dataset or a //group// (if grouping is used) the //Window size// will be set to the number of available rows and a single calculation will be generated for that window. 

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=====Examples=====

====Example #1====
>Create sliding aggregations (sums) for the column "value".

===Before (source table)===
^product ^sale date ^value ^
|GTX Plus  |  6/8/2018|  900|
|GTX Plus  |  6/24/2018|  1000|
|MG Special  |  6/22/2018|  60|
|MG Special  |  6/27/2018|  70|

===After (result table)===
^product ^sale date ^value ^ agg_sum ^
|GTX Plus  |  6/8/2018|  900|  **1900**|
|GTX Plus  |  6/24/2018|  1000|  **1060**|
|MG Special  |  6/22/2018|  60|  **130**|
|MG Special  |  6/27/2018|  70|  |

===Action parameters===
>New column: agg_sum
>Target column: value
>Aggregation mode: Sum
>Window size: 2
>Offset to:  Window start

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====Example #2 Illustrated===
{{transformations:slide_agg_pic1.png?1077}}

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{{transformations:slide_agg_pic2.png?718}}




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=====See also=====
  * [[transformations:aggregate|Aggregate]]