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How to automatise the grid production
- using model builder in ArcGIS
Ola Nordbeck
Statistics Norway
Objectives
• Basics
• Model benefits
• Document a model and its components
• Parameterize the tools
• Other tips
• Demo and exercise
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Basics
• Models are a series of geoprocessing tools that facilitate the
automation of complex or repetitive tasks
• Model Builder is a graphical interface that allows users to
easily create models using existing tools and data
• Requires no programming experience
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Basics – creating a model
Any tool, script or data can be included in the model by
dragging and dropping
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Basic – Model elements
Tools
Data
• Drag and drop into window • Drag and drop into
window
• Use Add button
• Drag and drop onto tools
• Fill in dialog
• In ArcMap, from the TOC
• Use Add button
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Basics – work flow
Derived data from one tool may be used as input to one or
more other tools
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Basic - Run States
Not ready to run –
input is set, tool
parameters are not
Ready to run
Already Run (tool and
output are shadowed)
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Model Benefits
• Models provide an easy way to interpret visual
representation of the data and workflow
• Models can be reused and shared, and are easy to modify if
necessary
• Models are much more convenient than running many tools
individually
• Models can be useful in project documentation
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Documentation
• Documentation for a model can be viewed in the model
dialog box, ArcCatalog, or Desktop Help
• On the model context menu
in ArcCatalog, choose Item
Description…, then click the
Edit icon to add information
• Basic documentation (name,
label and description) can
also be added on the model
properties dialog
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Parameters
• Any information used by a tool is a parameter
• Parameters can be hardcoded or set so a user can enter
values
• For example, it is often a good idea to set tool inputs as
parameters to make models more flexible
• It is also useful to make variables for some tool inputs and
expose them as parameters for user input (example coming
up)
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Parameters
• All tool parameters can be set using the Open… option on
the tool’s context menu
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Example
Variables
Shaded variables have hardcoded values
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Model Dialog with no Parameters or
Documentation
• Some models have no parameters
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Example with Parameters
Variables with a “P” are now parameters
• Variable names are more meaningful
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Model Dialog with Parameters and
Documentation
• Parameters are
listed in the order
they were added
to the model
• Order can be
changed in the
model properties
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Tips
• Working in the model builder application vs. using the model
as a tool
– Keep vs. delete intermediate data
– Run vs. Run Entire Model
• Iteration – added from Insert menu or set in the model
properties
• Add to Display
• Export to script
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Demo and exercise
Go through the tools used in the exercise:
“Production of gridded population statistics”
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