Longitude lat7 long8 lat8 long9 lat9 long10 lat10 yes

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Unformatted text preview: 10 Point 7, Longitude LAT7 LONG8 LAT8 LONG9 LAT9 LONG10 LAT10 Yes Yes Yes Yes Yes Yes Yes R R R R R R R N N N N N N N 143 152 162 171 181 190 200 151 161 170 180 189 199 208 9 10 9 10 9 10 9 Point Point Point Point Point Point Point 7, Latitude 8, Longitude 8, Latitude 9, Longitude 9, Latitude 10, Longitude 10, Latitude Note: The TIGER/Line(R) files contain a maximum of ten shape coordinates on one record. The number of shape records for a complete chain may be zero, one, or more. Complete chains with zero shape points (a straight line) do not have a Record Type 2. Coordinates have an implied six decimal places. See the Positional Accuracy section in Chapter 5 for more details. All TIGER records have a 1 character Record Type (RT) field as their first field; this identifies the type of the record you are parsing. Joining Looking at the datatypes above, it is clear that the polygon files contain the points which make up the polygon, but does not say what the polygon actually is. The polygon record, however, contains a Tiger/Line ID. This is the same id as some record of type 1, which describes a line. This line is adjacent to one of the sides of the polygon. The line's record describes what type of object the polygon represents (e.g., body of water, school, park, etc). This is stored in its CFCC field (Census Feature Code Class). A MapReduce pass must join the polygon to its associated line record to fill out a more complete record body to determine the type of the polygon, and thus how to render it. There is a second join between the BGN and Population datasets. BGN records contain the identifier for a location (city and state names), and its latitude and longitude coordinates. The population dataset has the name of the city/state entity, and its population -- but not its latitude and longitude. You should use MapReduce to execute a join so that you can complete the population entity data structure by filling in the latitude and longitude from the corresponding BGN record...
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