Automated Plotting with the Emme Desktop API

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Automated Plotting with the Emme Desktop API

• Peter HidasBureau of Transport Statistics
• Transport NSW

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Plotting in the Emme3 Desktop

• Emme Desktop provides excellent plotting
  functionality
• A wide range of model outputs can be represented
  graphically
• Frequent request for STM outputs
• Examples

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STM plots Road V/C-ratios
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STM plots Rail V/C-ratios
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STM plots Rail Stn Entries
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STM plots PT Time Savings
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STM plots PT mode share
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STM plots Access to Jobs
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Plotting in STM projects

• STM projects scenario modelling
• Up to 30-50 scenarios
• Steady increase in request for thematic plots
• Manual plotting
• Slow, expensive, error-prone
• Solution
• Automation

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Emme Desktop API

• Allows automation of user interaction with the
  Emme Desktop GUI
• Using Python scripts
• Easy to learn
• Basic knowledge of Python language
• Desktop API Guide and Reference
• Practical Example
• Develop own scripts

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Plotting Script

• Aim
• Automate frequent plotting tasks
• Create a reusable script for a variety of tasks
• Solution
• Separate the code from the input data
• Create an easy coding system for the input data
• Outcome
• make_plots.py

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make_plots.py (version 1)

• Based on Desktop API Reference
• Functions
• Connect to Emme Application
• Activate a Database
• Open a Worksheet
• Apply a View
• Set Base Scenario
• Set Active Scenario
• Set Path to save plot files
• Export Screen View
• Process input data

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Coding the Input Data

• Based on Emme input coding principle
• Use the first character in a line to identify the
  type of input
• Codes used
• p ltproject filenamegt or open
• d ltdatabase titlegt
• f ltfolder path to save filesgt
• w ltworksheet namegt
• v ltview namegt
• b ltbase scenario numbergt
• s ltscenario numbergt ltscenario numbergt
• Lines starting with any other character are
  ignored

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The Process Input Data Code

• Read input file line by line
• Split the line by space list of words
• If line0 p
• call setApp function with rest of the line as
  project name OR open
• If line0 d
• call setDatabase function with rest of the line
  as database title
• Etc

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Example Input Data Code
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Make_plots (v1) Evaluation

• Worked well for simple cases
• Limitations
• Only works with predefined fix worksheets
• without any change in parameters
• Needs automated Legend Title updating done by
  Emme synchronization
• Problems with bandwidth scaling
• fixed or automatically updated

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Make_Plots.py (version 2)

• Additional functions coded
• Force synchronisation of Legend Title
• not working?
• Set Legend Title
• Set values in layer parameters
• Define new input codes
• use first word instead of first character

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Example plot bus services

• Bus services by Bus Contract Region
• Special coding
• Select bus itins by region code
• Set view boundaries move with selected bus itins

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Input Code for Bus regions
New input code r for region call plotRegions
function with list of regions as input
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Version 3 set Title, scale, etc

• Many plots using same worksheet
• Combine input data for one plot in same line
  separated by
• New input code plot
• Input line structure
• plot ltTitlegtltdataFilegtltscalegtltFileNamegt

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Example Input Code
parts of the Legend Title
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Summary - Current Status

• Work in progress
• Updated/improved for each new task
• Issues
• bandwidth scale setting
• synchronization
• layer parameter names
• maximize worksheet window in Emme
• switch off panels (left/right)
• maximize Emme window
• integrate with Emme data (e.g. PT services)