Cholera MapReduce Application

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John Snow memorial and pub.jpg

Motivation

Epidemiology is the important study of "why certain people are getting ill."

We get a chance to make sense of the data in a relatively open ended studio.

Background

Imagine you are a physician in 1854 London in the midst of a cholera outbreak. Your theory that contaminated water is the cause meets resistance from the medical establishment which holds that it is spread via the air.

Imagine further that your friend Ada has left you access to computing.

Code To Use

We have made the data from this GIS Analysis available via methods:

class Location

double getDistanceTo( Location other )

class CholeraDeath

Location getLocation()

enum WaterPump

Location getLocation()

class SohoCholeraOutbreak1854

static CholeraDeath[] getDeaths()

Code To Implement

class: CholeraApp.java Java.png
methods: getValueRepresentation
createMapper
createCollector
package: mapreduce.apps.cholera.studio
source folder: student/src/main/java

getValueRepresentation

method: public static CholeraAppValueRepresentation getValueRepresentation() Sequential.svg (sequential implementation only)

createMapper

method: public static Mapper<CholeraDeath, WaterPump, Number> createMapper() Sequential.svg (sequential implementation only)

We have implemented WaterPump as an enum. You can access the enum constants of any enum via its values() method. For example:

for (WaterPump pump : WaterPump.values()) {
}

createCollector

Depending on your approach, you may be able to reuse one of your existing Collectors. Otherwise, implement one to go with your Mapper.

method: public static Collector<? extends Number, ?, ? extends Number> createCollector() Sequential.svg (sequential implementation only)

Testing Your Solution

Visualization

Original Map Drawn By John Snow:

Snow-cholera-map-1.jpg

Our Visualization App:

class: CholeraOutbreakVisualizationApp.java VIZ
package: mapreduce.apps.cholera.viz
source folder: student/src//java

CholeraOutbreak.png

Correctness

If you have chosen to go a different route than the ones we anticipated, do not worry about passing the test suite. Demo your work to an instructor in class and we can discuss its fitness.

class: CholeraStudioTestSuite.java Junit.png
package: mapreduce
source folder: testing/src/test/java