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

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

Basics – creating a model Any tool, script or data can be included in the model by dragging and dropping

Basic – Model elements Tools Data Drag and drop into window Use Add button Data Drag and drop into window Drag and drop onto tools Fill in dialog In ArcMap, from the TOC Use Add button

Basics – work flow Derived data from one tool may be used as input to one or more other tools

Basic - Run States Not ready to run – input is set, tool parameters are not Ready to run Already Run (tool and output are shadowed)

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

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

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)

Parameters All tool parameters can be set using the Open… option on the tool’s context menu

Shaded variables have hardcoded values Example Shaded variables have hardcoded values Variables

Model Dialog with no Parameters or Documentation Some models have no parameters

Example with Parameters Variables with a “P” are now parameters Variable names are more meaningful

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

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

Demo and exercise Go through the tools used in the exercise: “Production of gridded population statistics”