Possible duplicate: http://www.qtcentre.org/threads/1493...a-model-s-data

I have a QStandardItemModel of items where each row corresponds to a single object and each column corresponds to a property of that object. Here's an example using a student ID roster:

Qt Code: 
  1. ID	Gender		Grade	GPA
  2. 5	Male		12	3.8
  3. 4	Female		11	3.9
  4. 8	Female		12	3.5
  5. 19	Male		9	2.1
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My end goal is to let the user select one of the column names from a drop-down and have a second table display an aggregate of the values. For example, if the user selected Grade from the list, the second table would display the average GPA for each grade as follows:

Qt Code: 
  1. ID	Gender	Grade	GPA
  2. 		12	3.65
  3. 		11	3.9
  4. 		9	2.1
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Or similarly by Gender:

Qt Code: 
  1. ID	Gender	Grade	GPA
  2. 	Male		2.95
  3. 	Female		3.70
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Is there anything in Qt that performs that functionality? QSortFilterProxyModel seems to come close in terms of functionality, but as far as I can tell it only culls and sorts items, not summarizes them.