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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# Troubleshooting Slow processing times and memory errors Many of the Toolkit's functions for graph analysis ('Connectivity' tab) are highly demanding of computational time and RAM (see System Requirements). If you are encountering memory errors or runtimes that exceed your patience level, try an initial analysis using a smaller graph (larger hexagon size) or a more approximate solution. Use of incorrect input file format See Flowchart of analysis process for correct graph format file for each function. Input of the wrong graph format file (e.g., a lgf file into shortest-path BC) will result in an error message. Use of input layers with zero-valued habitat or cost Although in some instances CAT functions can complete when input habitat layers contain small areas of zero habitat value (which will be treated as barriers), generally the minimum habitat value should be a low but non-zero value. No areas of zero value should be present in the cost data used in min-cost-max-flow analysis. Use of inappropriate approximation parameters If the probability value (described in the section Connectivity Tab) for shortest-path and current-flow BC approximations is changed from the default value to a value that requires too large a subsample of the graph, the program may use the exact algorithm or may in some cases fail with an error message. "Network Flow.exe" crashes This may be caused by the issue described above (input layers with zero-valued habitat or cost). Or the 'convert decimals to integers' value may be set too high. Or the output filename given by the user (e.g., owl3nout in Tutorial Exercise 4) may have been incorrectly given a file suffix (e.g., .txt). If changing these parameters does not resolve the problem, please contact the developer. Use in regions/locales where the decimal separator is a comma rather than a period Although version 1.3 revises most functions to work in these regions (e.g., most of the world outside of the US and UK), there remain a couple of exceptions where this may causes errors: 1) Use of networkflow functions (e.g., min-cost flow) with either of these 2 options: -d // maximum distance for 'bounded-distance' metrics -f // supply fraction for min-cost-max-flow method To resolve this, use a distance value which is an integer, and use a supply fraction of 1 (the default). Reporting bugs There are likely to be issues that arise due to software bugs. The output tab may provide error messages that are helpful in identifying the problem. Please post a description of any problems to the CAT discussion forum or email the developer at klamathconservation@gmail.com. http://groups.google.com/group/connectivitytoolkit?hl=en
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