correct usage would be for example, with model being a model object already built and assume model is a summary level model (would also work for detail)

A_d_sector <- aggregateResultMatrix(model$A_d, "Sector", model$crosswalk)

But this is not well documented, no examples are given and inconsistent with other functions like adjustResultMatrixPrice() where one specifies the matrix like A_d and not having to pass model$A_d. and also having to pass the whole model$crosswalk is odd and then not clear what matrices can be passed... docs say "result matrix" but this actually fails for what are called result matrices like M and N that are not sector x sector.