Connectivity Analysis Toolkit License Version history Getting Started Overview of Methods Three Methods for Connectivity Analysis Subset Centrality: Mapping Linkages All-pairs Centrality: Mapping Landscape Connectivity Network Flow Analysis of Time Series Input files Output files Running the Toolkit from the GUI Hexmap Tab Graphs Tab Connectivity Tab Output Tab Running the Toolkit from the Command Prompt Flowchart of analysis process Examples Example 1: Shortest-path betweenness centrality (BC) Example 2: Shortest-path betweenness subset centrality Example 3: Comparison of subset and all-pairs current flow BC Example 4: Comparison of shortest-path and current flow BC Tutorial Exercise 1 - Mapping linkages with min-cost-max-flow subset centrality Exercise 2 - Mapping linkages with shortest-path subset centrality Exercise 3 - Mapping landscape connectivity with all-pairs centrality Exercise 4 - Mapping connectivity under climate change: analysis of time series Troubleshooting Related Resources System requirements Contacts & Credits
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# Output files Output textfiles Results of the centrality analyses are output as comma-delimited text files (.txt) of the format: hex_id, value Output shapefiles Shapefiles are produced by the Toolkit when the .asc file is initially converted to the hexmap format used by the Toolkit. These shapefiles allow the text file of results to be represented spatially. In order to display the results spatially, the text file (or files if several different analyses were run) will need to be joined to the 'hex_id' field of the shapefile created during the analysis process (see below). In ArcGIS, you can access data in delimited text files and work with them as tables using either ArcCatalog or the Add Data dialog box in ArcMap. Files with a .txt, .asc, or .csv extension are interpreted as comma delimited. You can join the table to a shapefile using either the Add Join function (under Data Management) or the Join Data dialog box, accessed by right-clicking a layer in ArcMap. Alternately, using ArcGIS Workstation, you can create an INFO file from the textfile and use JOINITEM to join it to a coverage created from the shapefile. We are considering development of a ArcGIS Toolbox to facilitate postprocessing of Toolkit output. If you have suggestions for this, please post comments to the Google Groups forum. Hexmaps files represent a format used internally by the Toolkit (and Hexsim, a program for spatial population viability analysis [see Related Resources]) Graph format files Various types of graph format files are produced in the course of analysis. Each one is appropriate to a different set of connectivity analysis methods. Thus it is possible to get meaningless results by producing the wrong input graph format for the analysis desired. The types of graph format files available are: LEMON graph format files (LGF) Nodes are listed first. Then edges (arcs) are listed. There are five fields per line in the edge section of the lgf: source_node, target_node, edge_label, edge_capacity, edge_cost. 1) LGF Directed - Used for time-series analysis using min-cost-max-flow 2) LGF Undirected - Used for min-cost-max-flow analyses (non-time-series, i.e., of a single map) Example of lgf file @nodes 1 2 ... @arcs label capacity cost 1 2 0 1000 1000 1 63 1 1000 1000 2 3 2 1000 1000 2 64 3 1065 1000 2 63 4 1000 1000 2 1 5 1000 1000 3 4 6 1000 1000 Edgelist textfiles Each line represents an edge. There are three fields per line: from_node, to_node, attribute 3) Edge list with Distance attribute - Used for shortest-path betweenness analyses 4) Edge list with Conductance attribute - Used for current flow betweenness analyses 5) Edge list - Directed - Used for PageRank analyses (experimental) Example of edgelist file 1 2 642.6068 1 157 644.6428 2 3 726.2068 2 158 704.6395 2 157 695.9301 2 1 642.6068 3 4 669.7904 3 159 679.8489 3 158 736.9523 3 2 726.2068 4 5 615.8793 4 160 612.6219 ...
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