Abstract: Disclosed is a method of applying a function to a set of data. Initially a tabular representation (400) of the set of data is displayed, the representation comprising a plurality of columns (435, 410 etc.). The data in the representation is grouped (625) in each column based upon an order (615) of the at least one column (605, 610) in the tabular representation. The method also generates a new column (1915) of data comprising a transform of existing column data (1920) contained in the tabular representation, wherein transform data within the new column depends upon a grouping context of the existing column data. Desirably the method further repositions (2120, 2130) the new column of data in the tabular representation and updates the transform data in the new column in accordance with a destination grouping context of a destination position of the new column in the tabular representation.