The vector graph widget could benefit from a few simple, but powerful improvements:

1. An aggregation function of 'sum of the average' or 'sumOfAvg'
2. Custom Labels for aggregated datasets

Currently, the sum and avg aggregations do not work correctly when aggregating multiple items that are already stored as rates in Zabbix. For example, network bandwidth in bps (bits per sec) or pps (packets per sec). When attempting to get the sum of multiple items together in this way, the calculation always adds a multiplier of the "num" of data points collected in the sql command within the PHP, which presents an incorrect data rate when trends is used as the data source. Adding a 'sumOfAvg' aggregation would sum the multiple datasets together like in AGGREGATION_SUM, but not add the "num" multipler or group by to provide a correct data rate for any chosen aggregation interval.

Additionally, when aggregating multiple data points in the vector graph the generic "Dataset #<NUM>" label can be confusing. Adding a new field called "Custom Label" would enhance the clarity on the graph tooltip to provide a more meaningful description of what is in the dataset especially when you have multiple dataset aggregations on one graph. Again, using network bandwidth as an example, if I aggregated all input bps data points, currently the label would be Dataset #1, and if i added another aggregated dataset for output bps it would be Dataset #2. It would be great if there was an extra text field to override those labels entirely. My preference would be that the custom label overrides the aggregation function and the "Dataset #1" label completely. For example:

"sumOfAvg(Dataset #1)" would be customizable to: "Ingest Bit Rate".

It looks like these features could be added pretty easily to the existing PHP code for versions 6.x, and would greatly improve the already great vector graph.