Patent ID: 9158832
Filing Date: 2015-10-13
Classification: G06F,G06T

Abstract:
1. A method for maintaining dependencies among a plurality of formulas, each formula of the plurality of formulas being associated with a cell of a table that includes a plurality of cells, the method, performed by a computing processor, comprising: prior to an event requiring recalculation of the table: maintaining an interval-based dependency graph in a computer memory such that each node of the graph is associated with at least one of the plurality of cells and each node of the graph represents a range of cells of the table on which a formula of the at least one cell depends; maintaining a range tree such that each node of the range tree is associated with the location of the cell within the table; assigning each of the plurality of formulas to a group, such that no formula of any group is dependent upon any other formula of the group, and each formula is assigned to only one group; receiving an input of a formula in the table; analyzing the received formula to identify which of the plurality of cells the received formula depends upon; searching the range tree to identify which of the depended-upon cells contain formulas; recursively searching the dependency graph to identify which of the cells of the plurality of cells of the table depend, either directly or indirectly, upon the received formula; based on the results of the range tree search and on the results of the recursive dependency graph search, assigning each cell of the plurality of cells to a group such that no cell of a group is dependent on another cell of a group, and each cell of the plurality is assigned to only one group; in response to an event requiring the reevaluation of one or more of the formulas of the plurality, reevaluating the formulas sequentially by group according to the group to which their respective cells are assigned, such; and displaying the result of the reevaluation on the table on a display device.