Invariant maps are tables that group sequences by position and residue. Along the top are the sequence numbering and the residue of the reference at each position. Along the left are row headers that represent the monomers that exist in the data-set. In each cell is the number of sequences that contain a specific monomer (row header) at a specific position (column header). For the example, in the table of somatostatin analogs shown in the figure below, there are 6 ‘A’ (alanines) and 28 ‘F’ (phenylalanines) at the 7th position in the alignment (column header). The data for each set of sequences in a cell is heat-mapped based on an activity column in the data-set. In the example below, cells are colored by the activity against the SST2 receptor with the most actives colored green and the least actives or inactives colored in red (see control at the bottom of table). Because each cell contains a number of sequences or a sequence set, the value used to heat-maps each cell is aggregated using the average, min or max at the users discretion.

To set up an interactive display, a second panel can be added (main menu->view->both panels) and a sequence table added. To create subset filtering using the invariant map, simply check the the invariant map box in the lower left panel (Subset 1 in the example below). Now any view that can be filtered by or marked by a subset (see upper right sequence table control) can use this filter to modify the row display. In the below example, the rows are filtered based on the user selection in the invariant map. Note that a quick view of the data is shown as a mouse over (shown below in the table inset). Working interactively with an invariant map and a sequence table is a great to query how a specific residue at a specific position affects the data. Simply click a cell in the table will allow a user to quickly navigate and explore many monomer-position pairs in a short time.