Microdata Output

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This topic describes model microdata output from a model developer perspective.

Related topics

• Model Code

Topic contents

• Introduction and outline
• Quick start How to build and run a model with microdata output capability
• General information General information

Introduction and outline

A model with microdata output enabled can output values of entity attributes during a run for later use.

Microdata output is controlled by run-time settings, build-time settings, and model code.

Run-time settings specify which attributes (if any) are output during the run. All attributes are available for selection at run-time without rebuilding the model.

Build-time settings determine whether a model can output microdata or not. Model code together with build-time settings determine when microdata output occurs during the simulation of an entity.

Microdata output is normally written to the model database. After a run completes, the OpenM++ dbcopy utility can extract microdata from the model database for downstream processing. A future OpenM++ utility will allow direct tabulation of microdata in the model database, including micro-level comparison operations between runs.

A build-time setting causes model microdata to be output in csv format to the run trace file instead of to the run database. This setting is targeted to model developers and is used in examples in this topic.

Quick Start shows how to build a model with microdata output capability and how to enable that capability in a model run. General Information about microdata output.

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Quick start

This subtopic contains the following sections.

• 1. Build model with microdata output capability
• 2. Create model ini file with microdata output options
• 3. Run model using microdata output

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1. Build model with event trace capability

Add the following statement to the model source code file RiskPaths/code/ompp_framework.ompp:

options microdata_output = on;

Build the Release version of RiskPaths.
In Windows, the model executable will be RiskPaths/ompp/bin/RiskPaths.exe.
In Linux, the model executable will be RiskPaths/ompp-linux/bin/RiskPaths.

In the same folder as the RiskPaths executable there may already be a copy of the default model ini file RiskPaths.ini. If not create it using your IDE or a text editor such as Notepad.

Edit RiskPaths.ini to have the following content:

[OpenM]
TraceToFile = true

[Parameter]
SimulationCases = 5

[Microdata]
Person = case_seed, age, union_status

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3. Run model using event trace

Launch the model in its bin directory using the ini file created in the previous step, being sure to also specify the OpenM.IniAnyKey option.

RiskPaths -ini RiskPaths.ini -OpenM.IniAnyKey true

In Windows you can run the Release version of RiskPaths from inside Visual Studio as follows:

• Solution Configurations to Release and Solution Platforms to x64
• Project Properties > Configuration Properties > Debugging > Command Arguments to
  -ini RiskPaths.ini -OpenM.IniAnyKey true
• Project Properties > Configuration Properties > Debugging > Working Directory to $(TargetDir)
• To launch the model, do Debug > Start without debugging or Press Ctrl-F5.

After the model runs the trace file RiskPaths.trace.txt should be present in the model bin directory and look like this:

Under construction

The model log will contain the following warning, which is expected.

Warning : model can expose microdata at run-time with output_microdata = on

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General information

A model built with microdata output enabled will output the following warning to the log whenever it is run:

 Warning : model can expose microdata at run-time with microdata_output = on

If this is not a concern, for example the model generates a synthetic population, this warning can be disabled by the following statement:

options microdata_output_warning = off;

Some entity attributes are created by the OpenM++ compiler to implement model functionality. For example, if an entity table has a filter, an identity attribute is created to implement it. These internal generated attributes are normally hidden but they can be made visible by the following statement:

options all_attributes_visible = on;

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