Hamburger Example

>(mapreduce 'nutrition '+
            '(hamburger bun cheese lettuce tomato mayo) t)
Mapping: HAMBURGER
   Emitted: (CALORIES 80)
   Emitted: (FAT 8)
   Emitted: (PROTEIN 20)
Mapping: BUN
   Emitted: (CALORIES 200)
   Emitted: (CARBS 40)
   Emitted: (PROTEIN 8)
   Emitted: (FIBER 4)
Mapping: CHEESE
   Emitted: (CALORIES 100)
   Emitted: (FAT 15)
   Emitted: (SODIUM 150)
Mapping: LETTUCE
   Emitted: (CALORIES 10)
   Emitted: (FIBER 2)
Mapping: TOMATO
   Emitted: (CALORIES 20)
   Emitted: (FIBER 2)
Mapping: MAYO
   Emitted: (CALORIES 40)
   Emitted: (FAT 5)
   Emitted: (SODIUM 20)
Reducing: SODIUM (20 150)  = 170
Reducing: FIBER (2 2 4)  = 8
Reducing: CARBS (40)  = 40
Reducing: PROTEIN (8 20)  = 28
Reducing: FAT (5 15 8)  = 28
Reducing: CALORIES (40 20 10 100 200 80)  = 450

((SODIUM 170) (FIBER 8) (CARBS 40) (PROTEIN 28) (FAT 28)
 (CALORIES 450))