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Valuestocols Transform

注意

Transforms are a part of the underlying language, which is not directly accessible to users. This content is maintained for reference purposes only. For more information on the user-accessible equivalent to transforms, see Transformation Reference.

For each unique value in a column, a separate column is created. For each row that contains the value in the source column, an indicator value is inserted in the new column.

  • This indicator value can be a literal value or the output of a function.

  • If no indicator value is generated, a null value is written.

This transform is used to generate indicator columns, which can be used in statistical analysis.

  • It evaluates entire cell values for uniqueness. It does not scan for individual elements in Object or Array data.

  • If a row in the source column contains a missing value, an indicator value is added in a new Empty column.

  • It is not appropriate for tabulating counts of strings or patterns in a column. SeeCountpattern Transform.

Optionally, you can specify a default value, which is applied to all non-indicator value cells in the new column.

注意

When this transform is applied in the data grid, it only identifies the unique values in the current sample. If there are other unique values in the entire dataset, new columns are not created for them when the transform is executed across the entire dataset.

Basic Usage

Source:

Data

Happy

Dog

Happy Happy Dog

Transformation:

valuestocols col:Data value:'X'

Results:

Data

Happy

Dog

Happy_Happy_Dog

Happy

X

Dog

X

Happy Happy Dog

X

Syntax and Parameters

valuestocols col:column_ref value:(expression) default:(expression) [limit:int_num]

Token

Required?

Data Type

Description

values tocols

Y

transform

Name of the transform

col

Y

string

Name of source column

value

Y

string

String literal, column, or function call that defines the value to use as the indicator value in any newly generated column

default

N

string

String literal, column, or function call that defines the value to use to indicate a false match in any newly generated column

limit

N

integer (positive)

Maximum number of columns to generate. Default is 50.

For more information on syntax standards, see Language Documentation Syntax Notes.

col

Identifies the column to which to apply the transform. You can specify only one column.

Usage Notes:

Required?

Data Type

Yes

String (column name)

value

For the valuestocols transform, this parameter specifies the value to insert in each row of a generated column where the column name of the generated column appears in the same row of the source column. This value can be a string literal, a column reference, or a function.

Usage Notes:

Required?

Data Type

Yes

String literal, column reference, or function call

default

Optionally, this parameter can be used to specify the value to insert in each row of a generated column where the column name of the generated column does not appear in the same row of the source column. This value can be a string literal, a column reference, or a function.

If this parameter is not specified, a missing value is inserted.

Usage Notes:

Required?

Data Type

No

String literal, column reference, or function call

limit

The limit parameter defines the maximum number of columns to create from the unique values detected in the source column. If not specified, the limit is 50.

注意

Be careful setting this parameter too high. In some cases, the application can run out of memory generating the results, and your results can fail.

Usage Notes:

Required?

Data Type

No. Default value is 50.

Integer (positive)

Examples

提示

For additional examples, see Common Tasks.

Example - Basic valuestocols

Source:

This dataset contains milestones for three employees who joined the company at the same time. The milestones were recorded and organized by date as individual items, so it's not easy to verify that all five milestones have been checked off for each employee:

  • Orientation

  • Contact Info

  • Acquire Computer

  • HR Policies Training

  • Product Training

Date

Name

Checklist

4/4/16

Bowie Kuhn

Orientation

4/4/16

Happy Chandler

Contact Info

4/4/16

Bowie Kuhn

Contact Info

4/4/16

Bowie Kuhn

Acquire Computer

4/4/16

Bud Selig

Product Training

4/4/16

Bud Selig

Orientation

4/5/16

Happy Chandler

HR Policies Training

4/5/16

Happy Chandler

Orientation

4/5/16

Happy Chandler

Acquire Computer

4/5/16

Bowie Kuhn

HR Policies Training

4/5/16

Bud Selig

HR Policies Training

4/5/16

Bud Selig

Contact Info

4/6/16

Happy Chandler

Product Training

Transformation:

The following transform creates columns for each of the values in the Checklist column and adds a yes value where there is a match for the row:

Transformation Name

Convert values to columns

Parameter: Column

onboardingChecklist

Parameter: Fill when present

'yes'

Results:

In the generated columns, you can quickly assess whether all three employees have completed an individual checklist item:

  • Bud Selig has not acquired his computer.

  • Bowie Kuhn has not had product training.

Date

Name

Checklist

Orientation

Contact_Info

Acquire_Computer

Product_Training

HR_Policies_Training

4/4/16

Bowie Kuhn

Orientation

yes

4/4/16

Happy Chandler

Contact Info

yes

4/4/16

Bowie Kuhn

Contact Info

yes

4/4/16

Bowie Kuhn

Acquire Computer

yes

4/4/16

Bud Selig

Product Training

yes

4/4/16

Bud Selig

Orientation

yes

4/5/16

Happy Chandler

HR Policies Training

yes

4/5/16

Happy Chandler

Orientation

yes

4/5/16

Happy Chandler

Acquire Computer

yes

4/5/16

Bowie Kuhn

HR Policies Training

yes

4/5/16

Bud Selig

HR Policies Training

yes

4/5/16

Bud Selig

Contact Info

yes

4/6/16

Happy Chandler

Product Training

yes

Example - Magazine subscriptions

This example shows how you can break out a column of nested values into separate rows and columns of data.

Source:

The following data covers magazine subscriptions for individual customers. Their subscriptions are stored in an array of values. You are interested in who is subscribing to each magazine.

CustId

Subscriptions

Anne Aimes

["Little House and Garden","Sporty Pants","Life on the Range"]

Barry Barnes

["Sporty Pants","Investing Smart"]

Cindy Compton

["Cakes n Pies","Powerlifting Plus","Running Days"]

Darryl Diaz

["Investing Smart","Cakes n Pies"]

Transformation:

When this data is loaded into the Transformer, you might need to apply a header to it. If it is in CSV format, you might need to apply some replace transformations to clean up the Subscriptions column so it looks like the above.

When the Subscriptions column contains cleanly formatted arrays, the column is re-typed as Array type. You can then apply the following transformation:

Transformation Name

Expand Array into rows

Parameter: Column

Subscriptions

Each CustId/Subscription combination is now written to a separate row. You can use this new data structure to break out instances of magazine subscriptions. Using the following transformation, you can add the corresponding CustId value to the column:

Transformation Name

Convert values to columns

Parameter: Column

Subscriptions

Parameter: Fill when present

CustId

Delete the two source columns:

Transformation Name

Delete columns

Parameter: Columns

CustId,Subscriptions

Parameter: Action

Delete selected columns

Results:

Little_House_and_Garden

Sporty_Pants

Life_on_the_Range

Investing_Smart

Cakes_n_Pies

Powerlifting_Plus

Running_Days

Anne Aimes

Anne Aimes

Anne Aimes

Barry Barnes

Barry Barnes

Cindy Compton

Cindy Compton

Cindy Compton

Darryl Diaz

Darry Diaz