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EXAMPLE - LIST Math Functions

This example describes how to generate random array (list) data and then to apply statistical functions specifically created for arrays.

Functions:

Item

Description

LISTSUM Function

Computes the sum of all numeric values found in input array. Input can be an array literal, a column of arrays, or a function returning an array. Input values must be of Integer or Decimal type.

LISTMIN Function

Computes the minimum of all numeric values found in input array. Input can be an array literal, a column of arrays, or a function returning an array. Input values must be of Integer or Decimal type.

LISTMAX Function

Computes the maximum of all numeric values found in input array. Input can be an array literal, a column of arrays, or a function returning an array. Input values must be of Integer or Decimal type.

LISTAVERAGE Function

Computes the average of all numeric values found in input array. Input can be an array literal, a column of arrays, or a function returning an array. Input values must be of Integer or Decimal type.

LISTVAR Function

Computes the variance of all numeric values found in input array. Input can be an array literal, a column of arrays, or a function returning an array. Input values must be of Integer or Decimal type.

LISTSTDEV Function

Computes the standard deviation of all numeric values found in input array. Input can be an array literal, a column of arrays, or a function returning an array. Input values must be of Integer or Decimal type.

LISTMODE Function

Computes the most common value of all numeric values found in input array. Input can be an array literal, a column of arrays, or a function returning an array. Input values must be of Integer or Decimal type.

Also:

Item

Description

RANGE Function

Computes an array of integers, from a beginning integer to an end (stop) integer, stepping by a third parameter.

RAND Function

The RAND function generates a random real number between 0 and 1. The function accepts an optional integer parameter, which causes the same set of random numbers to be generated with each job execution.

ROUND Function

Rounds input value to the nearest integer. Input can be an Integer, a Decimal, a column reference, or an expression. Optional second argument can be used to specify the number of digits to which to round.

Source:

For this example, you can generate some randomized data using the following steps. First, you need to seed an array with a range of values using the RANGE function:

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

RANGE(5, 50, 5)

Parameter: New column name

'myArray1'

Then, unpack this array, so you can add a random factor:

Transformation Name

Unnest Objects into columns

Parameter: Column

myArray1

Parameter: Paths to elements

'[0]', '[1]', '[2]', '[3]', '[4]', '[5]', '[6]', '[7]', '[8]', '[9]'

Parameter: Remove elements from original

true

Parameter: Include original column name

true

Add the randomizing factor. Here, you are adding randomization around individual values: x-1 < x < x+4.

Transformation Name

Edit column with formula

Parameter: Columns

myArray1_0~myArray1_8

Parameter: Formula

IF(RAND() > 0.5, $col + (5 * RAND()), $col - RAND())

To make the numbers easier to manipulate, you can round them to two decimal places:

Transformation Name

Edit column with formula

Parameter: Columns

myArray1_0~myArray1_8

Parameter: Formula

ROUND($col, 2)

Renest these columns into an array:

Transformation Name

Nest columns into Objects

Parameter: Columns

myArray1_0, myArray1_1, myArray1_2, myArray1_3, myArray1_4, myArray1_5, myArray1_6, myArray1_7, myArray1_8

Parameter: Nest columns to

Array

Parameter: New column name

'myArray2'

Delete the unused columns:

Transformation Name

Delete columns

Parameter: Columns

myArray1_0~myArray1_8,myArray1

Parameter: Action

Delete selected columns

Your data should look similar to the following:

myArray2

["8.29","9.63","14.63","19.63","24.63","29.63","34.63","39.63","44.63"]

["8.32","14.01","19.01","24.01","29.01","34.01","39.01","44.01","49.01"]

["4.55","9.58","14.58","19.58","24.58","29.58","34.58","39.58","44.58"]

["9.22","14.84","19.84","24.84","29.84","34.84","39.84","44.84","49.84"]

["8.75","13.36","18.36","23.36","28.36","33.36","38.36","43.36","48.36"]

["8.47","14.76","19.76","24.76","29.76","34.76","39.76","44.76","49.76"]

["4.93","9.99","14.99","19.99","24.99","29.99","34.99","39.99","44.99"]

["4.65","14.98","19.98","24.98","29.98","34.98","39.98","44.98","49.98"]

["7.80","14.62","19.62","24.62","29.62","34.62","39.62","44.62","49.62"]

["9.32","9.96","14.96","19.96","24.96","29.96","34.96","39.96","44.96"]

Transformation:

These steps demonstrate the individual math functions that you can apply to your list data without unnesting it:

Anmerkung

The NUMFORMAT function has been wrapped around each list function to account for any floating-point errors or additional digits in the results.

Sum of all values in the array (list):

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

NUMFORMAT(LISTSUM(myArray2), '#.##')

Parameter: New column name

'arraySum'

Minimum of all values in the array (list):

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

NUMFORMAT(LISTMIN(myArray2), '#.##')

Parameter: New column name

'arrayMin'

Maximum of all values in the array (list):

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

NUMFORMAT(LISTMAX(myArray2), '#.##')

Parameter: New column name

'arrayMax'

Average of all values in the array (list):

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

NUMFORMAT(LISTAVERAGE(myArray2), '#.##')

Parameter: New column name

'arrayAvg'

Variance of all values in the array (list):

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

NUMFORMAT(LISTVAR(myArray2), '#.##')

Parameter: New column name

'arrayVar'

Standard deviation of all values in the array (list):

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

NUMFORMAT(LISTSTDEV(myArray2), '#.##')

Parameter: New column name

'arrayStDv'

Mode (most common value) of all values in the array (list):

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

NUMFORMAT(LISTMODE(myArray2), '#.##')

Parameter: New column name

'arrayMode'

Results:

Results for the first four math functions:

myArray2

arrayAvg

arrayMax

arrayMin

arraySum

["8.29","9.63","14.63","19.63","24.63","29.63","34.63","39.63","44.63"]

25.04

44.63

8.29

225.33

["8.32","14.01","19.01","24.01","29.01","34.01","39.01","44.01","49.01"]

28.93

49.01

8.32

260.4

["4.55","9.58","14.58","19.58","24.58","29.58","34.58","39.58","44.58"]

24.58

44.58

4.55

221.19

["9.22","14.84","19.84","24.84","29.84","34.84","39.84","44.84","49.84"]

29.77

49.84

9.22

267.94

["8.75","13.36","18.36","23.36","28.36","33.36","38.36","43.36","48.36"]

28.4

48.36

8.75

255.63

["8.47","14.76","19.76","24.76","29.76","34.76","39.76","44.76","49.76"]

29.62

49.76

8.47

266.55

["4.93","9.99","14.99","19.99","24.99","29.99","34.99","39.99","44.99"]

24.98

44.99

4.93

224.85

["4.65","14.98","19.98","24.98","29.98","34.98","39.98","44.98","49.98"]

29.39

49.98

4.65

264.49

["7.80","14.62","19.62","24.62","29.62","34.62","39.62","44.62","49.62"]

29.42

49.62

7.8

264.76

["9.32","9.96","14.96","19.96","24.96","29.96","34.96","39.96","44.96"]

25.44

44.96

9.32

229

Results for the statistical functions:

myArray2

arrayMode

arrayStDv

arrayVar

["8.29","9.63","14.63","19.63","24.63","29.63","34.63","39.63","44.63"]

12.32

151.72

["8.32","14.01","19.01","24.01","29.01","34.01","39.01","44.01","49.01"]

13.03

169.78

["4.55","9.58","14.58","19.58","24.58","29.58","34.58","39.58","44.58"]

12.92

166.8

["9.22","14.84","19.84","24.84","29.84","34.84","39.84","44.84","49.84"]

13.02

169.46

["8.75","13.36","18.36","23.36","28.36","33.36","38.36","43.36","48.36"]

12.84

164.95

["8.47","14.76","19.76","24.76","29.76","34.76","39.76","44.76","49.76"]

13.14

172.56

["4.93","9.99","14.99","19.99","24.99","29.99","34.99","39.99","44.99"]

12.92

166.93

["4.65","14.98","19.98","24.98","29.98","34.98","39.98","44.98","49.98"]

13.9

193.16

["7.80","14.62","19.62","24.62","29.62","34.62","39.62","44.62","49.62"]

13.23

175.08

["9.32","9.96","14.96","19.96","24.96","29.96","34.96","39.96","44.96"]

12.21

149.17

Since all values are unique within an individual array, there is no most common value in any of them, which yields empty values for the arrayMode column.

In diesem Abschnitt: