Date: Sun, 17 Oct 2021 20:20:52 +0000 (GMT) Message-ID: <1731463183.47100.1634502052429@9c5033e110b2> Subject: Exported From Confluence MIME-Version: 1.0 Content-Type: multipart/related; boundary="----=_Part_47099_1319349844.1634502052429" ------=_Part_47099_1319349844.1634502052429 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Content-Location: file:///C:/exported.html STDEV Function

# STDEV Function

Computes the standard deviation across all column values of Int= eger or Decimal type.  The Standard deviation comes in two fl= avors:

• Population standard devia= tion computes the variance from all possible values.
• Sample standard deviation= computes from a subset or sample of all values.
• Since Trifacta=C2=AE has access to all available values, the c= omputation for population standard deviation is used across the entire data= set.

If a row contains a missing or null value, it is not factored into= the calculation. If no numeric values are detected in the input= column, the function returns `0`.

The square of standard deviation is variance. See VAR Function.

For a version of this function computed over a rolling window of rows, s= ee ROLLINGSTDEV Functi= on.

## Basic Usage

=20

pivot value:STDEV(myRating) group: postal_code li= mit:1

Output: Gene= rates a two-column table containing the unique values from the ```postal= _code``` column and the standard deviation of the group of values from = the `myRating` column for the `postal_code` valu= e. The `limit parameter defines the maximum number of output columns.```` ```

` `

``` Syntax= and Arguments =20 pivot value:STDEV(function_col_ref) [group:group_col_= ref] [limit:limit_count] Argument Required? Data Type Description function_col_ref Y string Name of column to which to apply the funct= ion For more information on the group and limit=  parameters, see Pivot Transform. For more information on syntax standards, see Language Documentation Syntax Note= s. function_col_<= /span>ref Name of the column the values of which you want to calculate the varianc= e. Column must contain Integer or Decimal values. Literal values are not supported = as inputs.  Multiple columns and wildcards are not supported. Usage Notes: Required? Data Type Example Value Yes String (column reference) myValues Examples Tip: For additional examples, see Common Tasks. This example illustrates how you can apply statistical functions t= o your dataset. Calculations include average (mean), max, min, standard dev= iation, and variance.  Source: Students took a test and recorded the following scores. You want to perf= orm some statistical analysis on them: Student Score Anna 84 Ben 71 Caleb 76 Danielle 87 Evan 85 Faith 92 Gabe 85 Hannah 99 Ian 73 Jane 68 Transform: You can use the following transforms to calculate the average (mean), mi= nimum, and maximum scores: derive type:single value:AVERAGE(Sco= re) as:'avgScore'=20 derive type:single value:MIN(Score)<= span> as:'minScore'=20 derive type:single value:MAX(Score)<= span> as:'maxScore'To apply statistical functions to your= data, you can use the  VAR and  STDEV functions, which can be used as the basis for other stat= istical calculations. =20 derive type:single value:VAR(Score)<= /span>=20 derive type:single value:STDEV(Score= )For each score, you can now calculate the variation of each one= from the average, using the following:=20 derive type:single value:((Score - a= vg_Score) / stdev_Score) as:'stDevs'Now, you want to apply grade= s based on a formula: Grade standard devi= ations from avg (stDevs) A stDevs > 1 B stDevs > 0.5 C -1 <=3D stDevs <=3D 0.5 D stDevs < -1 F stDevs < -2 You can build the following transform using the IF&nbs= p;function to calculate grades. derive type:single value:IF((stDevs = > 1),'A',IF((stDevs < -2),'F',IF((stDevs < -1),'D',IF((stDevs >= 0.5),'B','C'))))For more information, see  IF Function. To clean up the content, you might want to apply some formatting to= the score columns. The following reformats the stdev_Score an= d stDevs columns to display two decimal places: set col:stdev_Score value:NUMFORMAT(stdev_Score, = '##.00')=20 set col:stDevs value:NUMFORMAT(stDevs, '##.00')=20 derive type:single value:MODE(Score)= as:'modeScore' Results: Student Score modeScore avgScore minScore maxScore var_Score stdev_Score stDevs Grade Anna 84 85 82 68 99 87.00000000000001<= /p> 9.33 0.21 C Ben 71 85 82 68 99 87.00000000000001 9.33 -1.18 D Caleb 76 85 82 68 99 87.00000000000001 9.33 -0.64 C Danielle 87 85 82 68 99 87.00000000000001 9.33 0.54 B Evan 85 85 82 68 99 87.00000000000001 9.33 0.32 C Faith 92 85 82 68 99 87.00000000000001 9.33 1.07 A Gabe 85 85 82 68 99 87.00000000000001 9.33 0.32 C Hannah 99 85 82 68 99 87.00000000000001 9.33 1.82 A Ian 73 85 82 68 99 87.00000000000001 9.33 -0.96 C Jane 68 85 82 68 99 87.00000000000001 9.33 -1.50 D =20 See Also:=20 =20 =20 =20 Page:= =20 =20 =20 LIST Function= =20 =20 =20 =20 Page:= =20 =20 =20 MAX Function=20 =20 =20 =20 Page:= =20 =20 =20 MIN Function=20 =20 =20 =20 Page:= =20 =20 =20 COUNT Function=20 =20 =20 =20 Page:= =20 =20 =20 COUNTIF Functio= n=20 =20 =20 =20 Page:= =20 =20 =20 Enriching Data=20 =20 =20 =20 Page:= =20 =20 =20 MODE Function= =20 =20 =20 =20 Page:= =20 =20 =20 VAR Function=20 =20 =20 =20 Page:= =20 =20 =20 MODEIF Function<= /a>=20 =20 =20 =20 Page:= =20 =20 =20 LISTIF Function<= /a>=20 =20 =20 =20 Page:= =20 =20 =20 KTHLARGEST= IF Function=20 =20 =20 =20 Page:= =20 =20 =20 MAXIF Function=20 =20 =20 =20 Page:= =20 =20 =20 AVERAGE Functio= n=20 =20 =20 =20 Page:= =20 =20 =20 ANY Function=20 =20 =20 =20 Page:= =20 =20 =20 ANYIF Function=20 =20 =20 =20 =20   ```
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