A computer-implemented method, comprising: receiving category information having multiple categories defined for a geographic area of a digital map, each of the multiple categories having one or more category values; scheduling tasks to generate an annotated digital map with one or more processor circuits, the annotated digital map to include a visual representation of the multiple categories and associated category values for the geographic area of the digital map, the visual representation having different visual portions each representing a category as defined by an associated category value that changes over time, the visual portions each comprising a set of data points; generating, by circuitry, the annotated digital map with the visual representation in accordance with the scheduled tasks; the method further comprising traversing all data points for the visual representation; filtering the data points by one or more filter criteria; and storing the filtered data points in a gather data structure in a gather buffer, the gather data structure having a set of rows and columns, the rows to represent locations for data points and the columns to represent categories for the data points, with each row and column intersection to comprise a cell having a category value; accumulating category values across the gather data structure in one or more accumulate passes, comprising accumulating the category values across each row of the gather data structure in parallel with a graphical processing unit using multiple accumulate passes; storing the accumulated values in an accumulate data structure in an accumulate buffer. receiving category information having multiple categories defined for a geographic area of a digital map, each of the multiple categories having one or more category values; scheduling tasks to generate an annotated digital map with one or more processor circuits, the annotated digital map to include a visual representation of the multiple categories and associated category values for the geographic area of the digital map, the visual representation having different visual portions each representing a category as defined by an associated category value that changes over time, the visual portions each comprising a set of data points; generating, by circuitry, the annotated digital map with the visual representation in accordance with the scheduled tasks; the method further comprising traversing all data points for the visual representation; filtering the data points by one or more filter criteria; and storing the filtered data points in a gather data structure in a gather buffer, the gather data structure having a set of rows and columns, the rows to represent locations for data points and the columns to represent categories for the data points, with each row and column intersection to comprise a cell having a category value; accumulating category values across the gather data structure in one or more accumulate passes, comprising accumulating the category values across each row of the gather data structure in parallel with a graphical processing unit using multiple accumulate passes; storing the accumulated values in an accumulate data structure in an accumulate buffer.