How to Copy Variables Between Linked Data Sets

This article describes how to bring a variable over from one linked data set to another. This is useful when you wish to make calculations or include that data in filters/banners. JavaScript code can bring over the variable with a simple function, but if you want to use a variable from a different data set in R you either need to:

1. Use JavaScript to copy the data over to the other data set first, then use that variable in your R code.
2. Or merge the appropriate values from the variable using an ID variable(s) in your R code. That is, the data relationship link isn't automatically recognized by R.

This article covers the first method on how to create a new JavaScript variable in your data set that is the values of the variable in the linked data set.

Requirements

• A document with two data sets loaded in the Data Sources. 
• A Relationship between the files. See How to Create Data File Relationships for details.
• Note, this approach can only be used in a One to One or One to Many relationship where you are copying data from a data set that represents the One part of the relationship. It cannot be used with a Many to Many relationship which is instead performing Data Fusion.

Method

1. Select the Data Set in the Data Sources where you wish to add the variable. In this example, our data set is called File1 and we are bringing a variable over from File2. 

2. In the Data Sources tree, hover over any variable and click the Plus (+), then select Custom Code > JavaScript > Numeric or JavaScript > Text, depending on the format of the variable you wish to copy.

Note that Nominal, Ordinal, or Date/Time variables should be set up as a numeric JavaScript variable.

3. Select the variable in the second Data Set and drag it over to the JavaScript code panel.

You can also enter this manually using the format below:

Q.GetValue('source_variable_name', 'source_data_set')

The source_variable_name will match General > General > Name in Properties , and the source_data_set in this case would be File2.

Note, if the variable being added to your data set represents the Many in a One to Many relationship, i.e., has multiple matching records, you will need to indicate which matching record to map it to. For example, appending a [0] to the end of the code will take the first matching record:

Q.GetValue('source_variable_name', 'source_data_set')[0]

4. Change Data > Attributes > Structure to the correct data structure in Properties .

5. OPTIONAL: If you are copying over a categorical variable, such as Nominal or Ordinal, it will only carry over the values. You can, however, copy over the labels by doing the following:

• To copy the labels, select the source variable in the Data Sources tree and go to Data > Attributes > Values & Labels > Export > CTRL + C.
• To then apply this to your new variable, select it in the Data Sources tree and go to Data > Attributes > Values & Labels > Import > CTRL + V > OK.

If Your Data File is Loaded from the Displayr Cloud Drive

When specifying the file name that your source data is stored in, and the data file has been loaded from the Displayr Cloud Drive, then note the following:

• If the file is stored in the root directory/folder of the Displayr Cloud Drive, then you need to make no changes.
• If the file is stored in a folder on your Displayr Cloud Drive, then you should include the folder name(s) with double \\ between the folder names and the last folder and file name.

  • Example 1 - single folder:

    'Folder Name\\source_data_set'

  • Example 2 - multiple folders:

    'Folder One Name\\Folder Two Name\\Folder N Name\\source_data_set'

Next

How to Create Data File Relationships

How to Perform Data Fusion

How to Work with Multiple Data Files