Where20 Spatial Analytics 2010

Spatial Analytics WorkshopPete Skomoroch, LinkedIn (@peteskomoroch)Kevin Weil, Twitter (@kevinweil)Sean Gorman, FortiusOne (@seangorman)

#spatialanalytics

Introduction‣ The Rise of Spatial Analytics

‣ Spatial Analysis Techniques

‣ Hadoop, Pig, and Big Data

‣ Bringing the Two Together

‣ Conclusion

‣ Q&A





‣ Conclusion

‣ Q&A





‣ Conclusion

‣ Q&A

Spatial Analysis

Analytical techniques to determine the spatial

distribution of a variable, the relationship between

the spatial distribution of variables, and the

association of the variables in an area.

Pattern Analysis

Spatial Analysis Types

1. Spatial autocorrelation

2. Spatial interpolation

3. Spatial interaction

4. Simulation and modeling

5. Density mapping

Spatial Autocorrelation

Spatial autocorrelation statistics measure and analyze

the degree of dependency among observations in a

geographic space.

First law of geography: “everything is related to everything

else, but near things are more related than distant things.”

-- Waldo Tobler

Moran’s I - Random Variable

Moran’s I = .012

Moran’s I - Per Capita Income in Monroe County

Moran’s I = .66

Spatial Interpolation

Spatial interpolation methods estimate the variables

at unobserved locations in geographic space based

on the values at observed locations.

Natural Gas Demand in Response to February 21, 2003 Alberta Clipper cold front

$7.55

$14.00

$14.00

Henry

NYC

Chicago


$16.00

$30.00

$18.50

Henry

NYC

Chicago


$22.00

$37.00

$20.00

Henry

NYC

Chicago

Spatial Interaction

Spatial interaction or “gravity models” estimate

the flow of people, material, or information

between locations in geographic space.

Introduction‣ Motiviation

‣ Execution

‣ Prototype

‣ Service

‣ API

‣ Operations

‣ UX

Global Oil Supply and Demand Gravity Model

Simulation and Modeling

Simple interactions among proximal entities can

lead to intricate, persistent, and functional spatial

entities at aggregate levels (complex adaptive

systems).

Spatial Interdependency Analysis of the San Francisco Failure Simulation

InfrastructureTotal Number of Links

No. Links Congested

% Links Congested

%Volume Delay

Refined Products (National)

3,197 1 0.03% 0.05%Refined Products (MSA) 8 1 12.50% 93%

Power Grid (Regional) 1,942 4 0% N/A

Power Grid (MSA) 16 2 13% N/A

Density Mapping

Calculating the proximity and frequency of a

spatial phenomenon by creating a probabilistic

surface.

New York City Fiber Density Map

Standard GIS Architectures

Distributed Analytics

Queueing analysis tasks from disparate data sources

for agents to run across distributed servers to collate

back to the user as answers.

User

Request Queue

Disparate Data

Age

nts

Dis

trib

uted

Ser

vers

Analysis

User

Request Queue

Agent

Amazon S3

Amazon EC2

1. Rasterize2. Kernel

density calc3. Color map

(http://finder.geocommons.com/overlays/20148)

Vector Density Mapping Demo





‣ Conclusion

‣ Q&A

Data is Getting Big‣ NYSE: 1 TB/day

‣ Facebook: 20+ TB compressed/day

‣ CERN/LHC: 40 TB/day (15 PB/year!)

‣ And growth is accelerating

‣ Need multiple machines, horizontal scalability

Hadoop‣ Distributed file system (hard to store a PB)

‣ Fault-tolerant, handles replication, node failure, etc

‣ MapReduce-based parallel computation(even harder to process a PB)

‣ Generic key-value based computation interfaceallows for wide applicability

‣ Open source, top-level Apache project

‣ Scalable: Y! has a 4000-node cluster

‣ Powerful: sorted a TB of random integers in 62 seconds

MapReduce?‣ Challenge: how many tweets per

county, given tweets table?

‣ Input: key=row, value=tweet info

‣ Map: output key=county, value=1

‣ Shuffle: sort by county

‣ Reduce: for each county, sum

‣ Output: county, tweet count

‣ With 2x machines, runs close to 2x faster.

cat file | grep geo | sort | uniq -c > output























































But...‣ Analysis typically done in Java

‣ Single-input, two-stage data flow is rigid

‣ Projections, filters: custom code

‣ Joins: lengthy, error-prone

‣ n-stage jobs: Hard to manage

‣ Prototyping/exploration requires compilation

‣ analytics in Eclipse?ur doin it wrong...

Enter Pig

‣ High level language

‣ Transformations on sets of records

‣ Process data one step at a time

‣ Easier than SQL?

Why Pig?‣ Because I bet you can read the following script.

A Real Pig Script

‣ Now, just for fun... the same calculation in vanilla Hadoop MapReduce.

No, seriously.

Pig Simplifies Analysis

‣ The Pig version is:

‣ 5% of the code, 5% of the time

‣ Within 50% of the execution time.

‣ Pig ♥ Geo:

‣ Programmable: fuzzy matching, custom filtering

‣ Easily link multiple datasets, regardless of size/structure

‣ Iterative, quick

A Real Example

‣ Fire up your EMR.

‣ ... or follow along at http://bit.ly/whereanalytics

‣ Pete used Twitter’s streaming API to store some tweets

‣ Simplest thing: group by location and count with Pig

‣ http://bit.ly/where20pig

‣ Here comes some code!

http://bit.ly/whereanalytics

http://bit.ly/whereanalytics

http://bit.ly/where20pig

http://bit.ly/where20pig

tweets = LOAD 's3://where20demo/sample-tweets' as ( user_screen_name:chararray, tweet_id:chararray, ... user_friends_count:int, user_statuses_count:int, user_location:chararray, user_lang:chararray, user_time_zone:chararray, place_id:chararray, ...);

tweets = LOAD 's3://where20demo/sample-tweets' as ( user_screen_name:chararray, tweet_id:chararray, ... user_friends_count:int, user_statuses_count:int, user_location:chararray, user_lang:chararray, user_time_zone:chararray, place_id:chararray, ...);

tweets_with_location = FILTER tweets BY user_location != 'NULL';

normalized_locations = FOREACH tweets_with_location GENERATE LOWER(user_location) as user_location;

grouped_tweets = GROUP normalized_locations BY user_location PARALLEL 10;

location_counts = FOREACH grouped_tweets GENERATE $0 as location, SIZE($1) as user_count;

sorted_counts = ORDER location_counts BY user_count DESC;

STORE sorted_counts INTO 'global_location_tweets';

hadoop@ip-10-160-113-142:~$ hadoop dfs -cat /global_location_counts/part* | head -30

brasil 37985indonesia 33777brazil 22432london 17294usa 14564são paulo 14238new york 13420tokyo 10967singapore 10225rio de janeiro 10135los angeles 9934california 9386chicago 9155uk 9095jakarta 9086germany 8741canada 8201東京都 7696

東京 7121

jakarta, indonesia 6480nyc 6456new york, ny 6331

Neat, but...

‣ Wow, that data is messy!

‣ brasil, brazil at #1 and #3

‣ new york, nyc, and new york ny all in the top 30

‣ Pete to the rescue.





‣ Conclusion

‣ Q&A

Users by County

Lady Gaga

Tea Party

Dallas

Colbert





‣ Conclusion

‣ Q&A





‣ Conclusion

‣ Q&A

Questions? Follow us attwitter.com/peteskomorochtwitter.com/kevinweiltwitter.com/seangorman

Documents

Where20 Spatial Analytics 2010