AY1516 T2 Team CommuteThere Project Data Preparation

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PROJECT OVERVIEW

PROJECT MANAGEMENT

DOCUMENTATION

ANALYSIS & FINDINGS

Data Preparation

Initial Analysis

Further Analysis

Main Data Sets

Name of Data	Nature of Data	Number of Records (after cleaning)
bus_service_mapping	The actual bus service numbers are provided alongside with the bus service ids together with the date of entry of data into the database. The more recent the data depicts a more updated record.	335
location_gis_mapping	Coordinates of bus stops in WGS84 coordinate system are provided with the location_id of each bus stops and the date of entry when the data is entered into the database. The more recent the data depicts a more updated record.	4903
location _mapping	Names of each MRT stations and bus stops are provided together with the location_id. Date of entry of data when entered into the database is provided. The more recent the data depicts a more updated record.	5070
ride_data_20120109_20120115	Ez-link transactions of commuters of all types of commuters category from 9 Jan 2012 to 15 Jan 2012. Each transactions displays the tap-in and top-out of ez-link card.	Millions

Anomalies and Data Cleaning

Bus_service _mapping

An example of a record with duplicated entries of different entry_date

Final set of data where duplicates are removed with the most recent entry_date

Upon retrieving the data from the database, there was a total of 29522 records. However, the large number of records were attributed to duplicates of records where new entry of bus service mapping is entered with the date where data is stored in the database. To remove duplicates, dates are sorted according to the most recent dates first followed by the later dates. There are 335 unique records after removing the duplicates.

SQL statement used for retrieving the data: SELECT * FROM lta_ride_data_anly482.bus_service_mapping;

After cleaning the data, an additional step to sieve out relevant bus stops is required. As our analysis aims to identify the commuters’ behaviour when travelling inter-town, intra-town and island wide, we needed to sieve out bus stops that are within the former three mentioned. Intra town refers to commuters travelling within Tampines planning area; inter town refers to commuters travelling to neighbouring planning areas such as Paya Lebar, Pasir Ris, Bedok and Changi; island wide refers to commuters travelling outside of the east region. With that, using QGIS, we uploaded the bus stop data and clipped it with URA’s subzone shapefile. The bus stop data is then filtered accordingly as shown below.

	Planning Area(s):
Intra town bus stops	Tampines
Inter town bus stops	Paya Lebar, Bedok, Pasir Ris, Changi, Changi Bay
Island wide bus stops	Ang Mo Kio, Bishan, Boon Lay, Bukit Batok, Bukit Merah, Bukit Panjang, Bukit Timah, Central Water Catchment, Choa Chu Kang, Clementi, Downtown Core, Geylang, Hougang, Jurong East, Jurong West, Kallang, Lim Chu Kang, Mandai, Marina East, Marina South, Marine Parade, Museum, Newton, Novena, Orchard, Outram, Pioneer, Punggol, Queenstown, River Valley, Rochor, Seletar, Sengkang, Serangoon, Singapore River, Simpang, Sungei Kadut, Straits View, Tanglin, Tengah, Toa Payoh, Tuas, Western Water Catchment, Woodlands, Yishun

Location_gis_mapping

An example of a record with duplicated entries of different entry_date

Records with (0,0) coordinates are removed

Final set of data with SVY21 coordinates where duplicates are removed with the most recent entry_date

Just like bus_service_mapping, location_gis_mapping data also has duplicated entries of the same location_id but with different enrty_date. There are 442458 records upon retrieving this data. There is a total of records upon retrieving this data set from the database. After removing duplicates that has the older entry_dates, there is a total of 4903 records.

There are 27 records that have (0,0) as the coordinates. This appears to be an anomaly because these coordinates do not fit into the coordinates of Singapore island. With that, these records are also removed from the data for this project. As such, ez-link records in ride_data_20120109_20120115 with these location_ids are also removed since this will not help in the analysis of commuters’ patterns.

SQL statement used for retrieving the data: SELECT * FROM lta_ride_data_anly482.location_gis_mapping;

Location_mapping

Ride_data_20120109_20120115