The Map column allows you to connect data sets using a key value.
Connect datasets
The gear menu contains a shortcut that makes it easy to connect two groups of data, where you have a key value, with the same name, in both groups.
For example, here we have a two groups of data:
- Data: contains ID and Value
- Labels: contains ID and Description
The key value is the ‘ID’ column, where we want the corresponding ‘Description’ from the group Labels, to also be listed, in a new column, in the group Data.
In query language, this would be a one-to-many relationship (e.g., there is one unique ID in the group Label, and non-unique ID entries in the group Data.
To connect the groups:
- Click the gear menu on the ‘ID’ column in Data
- Select Map
- Chose from the list of options (Here ‘Description’)
The options shown in the Map menu are automatically populated, by all groups with a column having the same key value.
In this example, there is only one column that can be mapped to, ‘Description’. If there were other groups containing a column named ‘ID’, they would also be listed as an option for mapping.
Create a map column
You can add a Map Column using the Other drop-down menu.
Map
The key value you want to map.
Method
There are three methods:
- Specified
- From Columns
- Intervals
You can also define intervals. For example, you could use this option to map a numerical value to a letter grade.
Type
This option defines the column types for the input and output. This option is only shown when you are using the ‘Specified’ option.