After a mapping has been performed on a project, the mapping computation can be repeated on that project - with the same Read Data or after addition or removal of one or more files, with the same mapping parameter settings or with different ones by pressing the Start button. If the “Incremental reference mapper analysis” checkbox on the Parameters tab is checked and no change has been made to the Reference, this computation will use the current parameters settings when mapping any reads new to the project; this re-analysis will take much less time than the initial analysis, since previously mapped reads will remain aligned to their existing reference locations. Changes to some parameter settings (such as those on the Input and Computation sub-tabs of the Project Tab) will have no effect on reads already included the prior mapping computation