StatisticsCalculator Example
From Fmepedia
The attached workspace provides an example workspace showing how the StatisticsCalculator transformer might be used - in particular the Group-By function on the transformer, which is new for FME2008.
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Scenario
The simple scenario here is to find the average annual expenditure on toothpaste for each postal code in the City of Interopolis.
Source Data
The source data is a set of address points, and a set of postcode (zipcode) boundaries.
Toothpaste expenditure per household is simulated by attaching a random number to each address.
Above: Sample of source data showing addresses and postcode boundaries
Workspace
The first thing to do in the workspace - after reading the source and generating some random data - is to overlay the address points and zipcode boundaries so that each address is tagged with a postcode attribute.
Now the StatisticsCalculator is set to calculate the number of addresses per postcode, and the average toothpaste expenditure per postcode. The means to do this is the Group-By function, which here is set to the zipcode attribute.
Above: The StatisticsCalculator settings dialog. Note the attribute to analyze and group-by parameters
Above: The workspace as a whole [nb: zipcode on the output is coloured red as the group-by attributes are erroneously being un-exposed - I'm sure this will be fixed soon]
Output
Note in the above output how 12292 features enter the StatisticsCalculator, but only 7 features exit. This indicates there are 7 groups (different postcodes) on which statistics were created.
The output is written to a plain CSV file.
Above: The output (tidied up slightly for clarity)
