ModelBuilder in ArcGIS Automating Geoprocessing

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ModelBuilder in ArcGIS Automating Geoprocessing

• Burlington County GIS Users Group Meeting
• October 21, 2005
• Merrilee Torres

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What is a model?

• A representation of reality
• Example a recipe

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What can I do with ModelBuilder?

• Automate work flow by stringing processes
  together (can be saved to run again)
• Design a model
• Implement a model
• Create a model containing methods procedures to
  be shared with others
• Show the process used to create output (flow
  diagrams)

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How do I access ModelBuilder?
(demo)

• Start ArcCatalog
• Open ArcToolBox
• Right-click ArcToolBox choose
  New Toolbox. Type a name for the toolbox. (Note-
  the new toolbox could also be created in a folder
  or geodatabase)
• Right-click your new toolbox and choose New
  model. Click the model, choose Properties, click
  the General tab give it a name
• Optionally, you can click the Environment tab,
  click on a setting and then click the Values.
  button to set the value for various environment
  settings such as
• Current workspace - a folder or geodatabase to
  use for inputs and outputs data
• Scratch workspace - folder where results that
  will not be permanently maintained will be placed

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The ModelBuilder Interface ModelBuilder window
where you edit, test and run models
Navigate
Zoom In
Auto Layout
ModelBuilder Canvas
Zoom out
Continuous Zoom
Full Extent
Run
Select
Add Connection
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The ModelBuilder Interface, cont.

• Auto Layout button organizes your model elements
  into easily readable linear patterns
• Navigate tool lets you navigate through the
  model from one element to the next, forward or
  backward
• Add Connection tool used to add connections
  between data the tool that will accept that
  data as an input
• Overview window displays the entire model at all
  times. Useful when working on a piece of a large
  model to see where you are in relation to the
  entire model- shows your location
• Run button runs the processes that have not
  already been run. Or, to run entire model choose
  ModelRun Entire Model or double click the model
  in ArcToolBox. To run 1 isolated process, click
  the tool choose Run
• If need to re-run model, choose Model--Validate
  Entire Model first (you may need to delete any
  data that was previously created)

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The ModelBuilder Interface, cont.

• Model elements have 3 states
• Not ready to run (parameters arent defined)
• Ready to run (all elements are colored)
• Already run (elements are colored and shaded)

Usually referred to as Derived Data
output
Input
tool
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Start building your model!

• First, plan what you want to do
• What data will you need?
• What processes will you run on each dataset?
• If the ModelBuilder Window is closed, right-click
  the model and choose Edit to open for editing
• Add data layers to the canvas using the or
  drag them in from ArcCatalog
• Drag tools onto the canvas from ArcToolbox
• Connect data layers to tools using the tool
• (demo)

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Creating input parameters for running in a dialog
(like running a tool)
While editing Model in ModelBuilder Canvas..

• Create input parameters for tools
• define a default value for the parameter by
  double-clicking the tool entering appropriate
  value
• right-click on tool Make Variable- From
  Parameter and choose the parameter (repeat for
  1)
• must also right-click created Value Model Element
  Parameter
• In order for created data to persist on the hard
  drive when run in dialog, must set all derived
  data elements as Model Parameters (right-click
  derived data element, choose Model Parameter )
• Can also set input data elements to parameters to
  allow user input
• Save the model close

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Running a model in a dialog

• Once the model is created, tested saved in the
  ModelBuilder Window, it can be run as a dialog
  from ArcToolBox (like a tool)
• In ArcToolBox, navigate to your tool
• Double click the tool enter the necessary
  parameters
• Optionally, change the name location of input
  or output data
• Click OK
• Check specified output folder for results