v.net.connectivity - Computes vertex connectivity between two sets of nodes in the network.
vector, network, connectivity
v.net.connectivity v.net.connectivity --help v.net.connectivity input=name [arc_layer=string] [node_layer=string] [arc_column=name] [arc_backward_column=name] output=name [node_column=name] [set1_cats=range] [set1_where=sql_query] [set2_cats=range] [set2_where=sql_query] [--overwrite] [--help] [--verbose] [--quiet] [--ui] Flags: --overwrite Allow output files to overwrite existing files --help Print usage summary --verbose Verbose module output --quiet Quiet module output --ui Force launching GUI dialog Parameters: input=name [required] Name of input vector map Or data source for direct OGR access arc_layer=string Arc layer Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name. Default: 1 node_layer=string Node layer Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name. Default: 2 arc_column=name Arc forward/both direction(s) cost column (number) arc_backward_column=name Arc backward direction cost column (number) output=name [required] Name for output vector map node_column=name Node cost column (number) set1_cats=range Set1 category values Example: 1,3,7-9,13 set1_where=sql_query Set1 WHERE conditions of SQL statement without 'where' keyword Example: income < 1000 and inhab >= 10000 set2_cats=range Category values Set2 category values set2_where=sql_query Set2 WHERE conditions of SQL statement without 'where' keyword Example: income < 1000 and inhab >= 10000
v.net.connectivity computes vertex connectivity between two sets, i.e. the minimum number of vertices whose removal would separate two given sets.
Two sets (set1 and set2) are specified by respective layer, where and cats parameters. Similarly to v.net.flow module, capacities of nodes can be given by node_column option. v.net.connectivity finds the set of nodes of minimum total capacitiy separating the two given sets and outputs map containing points on the positions of these nodes. Default capacity, which is used when no column is specified, is one.
The following command finds the minimum number of intersections separating roads on the left bank from roads on the right bank. v.net.connectivity input=roads output=roads_conn set1_where="bank=left" \ set2_where="bank=right" v.net.connectivity input=airtraffic output=connectivity \ set1_where="name=JFK" set2_where="name=Heathrow" node_column=capacity
v.net, v.net.flow, v.net.bridge
Daniel Bundala, Google Summer of Code 2009, Student Wolf Bergenheim, Mentor Last changed: $Date: 2014-12-24 14:28:25 +0100 (Wed, 24 Dec 2014) $
Available at: v.net.connectivity source code (history) Main index | Vector index | Topics index | Keywords index | Graphical index | Full index 2003-2016 GRASS Development Team, GRASS GIS 7.2.0 Reference Manual
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.