Derived Parameters

FlowJo allows you to add new parameters to your data by performing operations on existing parameters. These could include operations like the creation of ratio parameters and "zooming" to a particular range of a parameter. This tool also will apply a Gain or Offset to an existing parameter and set the range for scale values. To learn about each of these new parameter types, click here. Once created, they behave like parameters that were collected at acquisition: you can display them, gate on them, calculate statistics on them, etc.

What follows are the basic mechanics of creating a generic Derived Parameter:

1. Click on a sample in the workspace, go to the Tools menu and select Derived Parameters. This will bring up the Derived Parameter window (at right).
2. Give your new parameter a name (default is AlgParm)
3. Insert a Reference parameter from the dropdown menu labeled Insert Reference.
4. If you are using a function for your parameter: select it from the dropdown menu labled Insert Function, then select your second reference parameter (e.g. FL1-H / FSC-H) or type in the number(s) you are using in your operation.
5. Select the Scale for your new parameter (Lin or Log) and set the X-axis range Min and Max values if desired.
6. Preview the derived parameter by clicking on the Preview button.
7. Apply the new parameter to a single sample by clicking OK, or to a group by selecting the group in the workspace and then clicking the Apply to Group button in the Derived Parameter window.
8. To view your new parameter, open a Graph Window and select the new parameter from the X or Y axis dropdown menus.

A light blue bar will appear in the Workspace when the new parameter has been created.

It is important to note that while the new parameters are not added to the original data file, they can become a part of a new data file if you choose to Export/Concatenate your file(s). This will eliminate the need to recreate the parameter(s) when using the data in a different workspace.