Batch Analyst

The OpenTripPlanner Analyst web services produce map tiles or rasters derived from a single shortest path tree, which is to say that they reveal information (often travel time) about the geographic area covered by a graph from the perspective of a single (but freely movable) origin point.

The OpenTripPlanner Analyst batch framework covers a larger range of use cases, which may involve accumulating or aggregating results derived from many independently built single source shortest path trees. Rather than a web service that serves map tiles, the batch framework includes a command-line program that is configured via Spring dependency injection XML. The locations and other attributes of path search endpoints (origins and destinations) may be loaded from Shapefile, CSV, or raster formats. Results may be saved back to a raster or a CSV file for further manipulation or analysis in a desktop GIS package like QGIS or a statistics package like R.

The config XML declaratively configures and instantiates Spring "beans" which represent the origin set, destination set, and aggregate function to apply over the destinations. Properties of the BatchProcessor itself allow the user to customize the search process, and a PrototypeRoutingRequest may be provided to set OTP routing parameters such as mode of transport or maximum walk distance (which would be specified in the OTP query string when using the REST routing service).

Here is an example batch-context.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:sec="http://www.springframework.org/schema/security"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
           http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-2.0.xsd">

    <context:annotation-config />
    
    <bean class="org.opentripplanner.analyst.request.SampleFactory" />
    <bean class="org.opentripplanner.routing.impl.DefaultRemainingWeightHeuristicFactoryImpl"/>
    <bean class="org.opentripplanner.routing.algorithm.GenericAStar"/>
    <bean class="org.opentripplanner.analyst.batch.IndividualFactory" />
    <bean class="org.opentripplanner.analyst.core.GeometryIndex" />
    
    
    <!-- specify a GraphService, configuring the path to the serialized Graphs -->
    <bean id="graphService" class="org.opentripplanner.routing.impl.GraphServiceImpl">
        <property name="path" value="/var/otp/graphs/{}/" />
        <property name="defaultRouterId" value="arbor" />
    </bean>


<!-- this creates a population directly from of a list of individuals -->
<!--     
	<bean id="origins" class="org.opentripplanner.analyst.batch.BasicPopulation">
        <property name="individuals">
            <list>
			    <bean class="org.opentripplanner.analyst.batch.Individual">
				    <property name="label" value="UMich" />
			        <property name="lon" value="-83.73820" />
			        <property name="lat" value="42.27490" />
			    </bean>
            </list>
        </property>
    </bean>
-->

<!-- this creates a population arranged on a regular grid that can later be saved as an image -->
	<bean id="destinations" class="org.opentripplanner.analyst.batch.SyntheticRasterPopulation">
        <property name="left" value="-84.14" />
        <property name="right" value="-83.41" />
        <property name="bottom" value="42.07" />
        <property name="top" value="42.45" />        
        <property name="crsCode" value="epsg:4326" />
        <property name="cols" value="1280" />
        <property name="rows" value="1024" />        
	</bean>
 
<!-- this loads a population from a comma-separated flat text file -->

	<bean id="origins" class="org.opentripplanner.analyst.batch.CSVPopulation">
        <property name="sourceFilename" value="/home/abyrd/access/annarbor.csv" />
        <property name="latCol" value="1" />
        <property name="lonCol" value="2" />
        <property name="labelCol" value="0" />
        <property name="inputCol" value="3" />        
	</bean>

<!-- aggregate results are no longer stored in individuals so populations can be reused -->
<!-- <alias name="destinations" alias="origins"/> -->
	
<!-- define the main batch processor, which will build one shortest path tree from each origin to all destinations -->
	
	<bean id="batchProcessor" class="org.opentripplanner.analyst.batch.BatchProcessor"> 
        <property name="outputPath" value="/home/abyrd/access/out1834_clamp.tiff" />
        <property name="routerId" value="arbor" />
        <property name="date" value="2012-07-12" />
        <property name="time" value="08:00 AM" />
        <property name="timeZone" value="America/New_York" />
        <property name="prototypeRoutingRequest">
			<bean class="org.opentripplanner.routing.core.PrototypeRoutingRequest">
				<!-- Set default routing parameters here -->
		        <property name="maxWalkDistance" value="400000" />
		        <property name="clampInitialWait" value="1800" />
		        <property name="arriveBy" value="false" />
			</bean>
		</property>		
		<!-- 
        <property name="aggregator"> 
            <bean class="org.opentripplanner.analyst.batch.aggregator.ThresholdSumAggregator">
                <property name="threshold" value="3600" />
            </bean>
        </property> 
        -->
        <property name="accumulator"> 
            <bean class="org.opentripplanner.analyst.batch.ThresholdAccumulator">
                <property name="threshold" value="3600" />
            </bean>
        </property> 
	</bean>

</beans>

The number of 18-35 year old residents in the Ann Arbor, Michigan area that can reach each raster cell in less than 1 hour of transit + walking (blue=5000, yellow=100000, green=200000).