In the Gretl GUI one can define a new variable by ADD -> DEFINE NEW VARIABLE. This works quite nicely, and I can define something like y=cos(2*pi*x/5) and use it in a regression. In addition, I can right-click on y, select EDIT ATTRIBUTES, and edit the formula, changing it to y=cos(2*pi*x/10) for example. In general, this is a very useful feature of Gretl. However, if I save the file and reload it the "formula" becomes a "description" in the EDIT ATTRIBUTES window. This means I can no longer edit the formula. Is there a way to retain the ability to edit the formula after saving a session? Tom