1. Development of an Open Matrix Emme Integration Tool
INRO Model City Portland
September 21, 2016

2. What is OMX and why should I care? How do EMME and OMX work together?
Today’s Talk
What is OMX and why should I care?
How do EMME and OMX work together?
Example integrations for
LCOG’s mode choice model
Oregon Metro’s new multi-criterion evaluation toolkit

3. What is OMX and why should I care?

4. Purpose of OMX
Is a simple standard matrix format for storing and transferring matrix data that can be easily adopted
For
Anyone managing transportation data with a matrix structure
Who
Wants a portable and open format for storing and exchanging that data
That
Is easy to understand, can be used in custom programs/scripts, and supports commercial products
Unlike
Existing solutions that are either proprietary, cumbersome, slow, and/or too large

5. Who We Are
A diverse group of agency, consultant, and research modelers
Formed a working group to define and implement the file format for use in modeling
Similar to the HTML working group for example
Formed in early 2013, shortly after TRB
Periodically meet to update the standard/project

6. We Believe OMX will:
make model development and application easier across models and software packages
help spur industry research and innovation by having a shared data structure (think shapefile, GTFS)
enable researchers, students, agencies, and practitioners to collaborate in ways that are currently difficult, cumbersome and error-prone

7. What is OMX Open matrix is a published file format (i.e. skims.omx)
Based on open-source HDF-5 file storage technology
Binary data storage with compression
Stores multiple matrices in one file and includes zone indexes/lookups
Can contain additional attributes for matrices and indexes
Python, R, Java, C#, C++, Ruby interfaces available
Built-in support in EMME, VISUM, and TransCAD
Supported by CT-RAMP and DaySim ABM platforms

8. How do EMME and OMX work together?

9. inro.emme.data.matrix.export_to_omx

10. inro.emme.data.matrix.import_from_omx

11. Example integrations

12. EMXtoOMX Command Line Tool
EMME tools work well for basic matrix I/O
However, we needed something that easily fits within our typical DOS-based overall model workflow
Thus, we developed a little command line tool for matrix I/O
Export python EMXtoOMX.py proj.emp 9999 mats.omx -e mf1 mf2
Import python EMXtoOMX.py proj.emp 9999 mats.omx -i mf1 mf2

13. EMXtoOMX Command Line Tool Steps
Starts EMME
Loads the specified project and scenario
If export:
Exports the matrices using inro.emme.data.matrix.export_to_omx
Removes appended matrix names in order to keep tool interface simple
mf1_timau  mf1
If import:
Imports the matrices using inro.emme.data.matrix.import_from_omx

14. LCOG Model Choice Model Example
Eugene MPO C++ mode choice model previously did binary databank I/O, which is no longer supported
So we revised the C++ program by linking in the OMX/HDF5 libraries and recompiling the program
Updated the overall model run script as well:
Export matrices
python EMXtoOMX.py LCOG.emp 9999 mos.omx -e mo10 mo11 mo12 mo13 …
python EMXtoOMX.py LCOG.emp 9999 mds.omx -e md02 md03 md34
python EMXtoOMX.py LCOG.emp 9999 mfs.omx -e mf294 mf295 …
Run model
lcogmc.exe hbw.ctl report.rpt
Read back in updated matrices python EMXtoOMX.py LCOG\LCOG.emp 9999 mfs.omx -i mf81 mf82 mf83 …

15. Metro MCE Toolkit Example
Portland Oregon MPO multi-criterion evaluation (MCE) / benefits-cost analysis (BCA) social return on investment (SROI) Python/pandas-based calculator currently being development
Requires zone, OD, and link-level model outputs for a base and build scenario
Monetizes the differences and compares the benefits to scenario costs
Model also run via cmd line so data export looks similar to LCOG:
Export base scenario skims and trips
python EMXtoOMX.py nb_skimsbank.emp 4 mfs.omx -e mf1 mf2 …
python EMXtoOMX.py nb_assignbank.emp 4 mfs.omx -e mf8 mf7 …
Export build scenario skims and trips
python EMXtoOMX.py b_skimsbank.emp 4 mfs.omx -e mf1 mf2 …
python EMXtoOMX.py b_assignbank.emp 4 mfs.omx -e mf8 mf7 …

16. Resources

17. OMX project, code, packages, examples, etc.
Resources
OMX project, code, packages, examples, etc.
EMME OMX cmd line tool
HDF5
pandas (basically Python’s version of R)

18. Contacts Ben Stabler ben.stabler@rsginc.com www.rsginc.com
Portland, OR