DifferenceColumn Process
Add a difference column based on an existed numeric column
| name | income |
|---|---|
| John | 50,000 |
| Marry | 60,000 |
| Peter | 100,000 |
| Donald | 80,000 |
->pipe(new DifferenceColumn(array(
"diff" => "income"
)))
| name | income | diff |
|---|---|---|
| John | 50,000 | 50,000 |
| Marry | 60,000 | 10,000 |
| Peter | 100,000 | 40,000 |
| Donald | 80,000 | -20,000 |