Script Detailed Description

The script finds nodes which initiate "start" branches. "Start" branches are those branches which do not have other branches flowing into them. These must be identified for uniformity between the ArcView and naUTilus numbering systems. ArcView assigns numbers to these nodes, while naUTilus does not.

For this script to function, the node numbers in the node theme must match with those in the branch theme. This is accomplished by creating the node theme from the branch coverage's nodes.

The script finds the attribute tables of both themes. In the node theme, the script creates a new field called "Node_Type". In the branch theme, the script finds the field listing the "to nodes". The "to node" of a branch is the the branch's terminal node. A list of "to nodes" is created and compared to the complete list of node numbers in the node theme. Those nodes which are not in the list of "to nodes" have no branch flowing into them and are flagged with a -1 in the "Node_Type" field. Other nodes are numbered by unique values.

The unique values created by this script in the "Node_Type" field will be used as the node identification numbers for input to naUTilus. The output from naUTillus can be joined to the node attribute table by that identification number.

The updated version of this script also identifies what ArcView considers the last node of the system. This node is not, however, considered the last node in the naUTilus numbering system. It identifies what ArcView considers the last node by finding the only node which is not listed as a "From Node" in the ISBL branch theme.

Key Avenue commands used:

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