I have a road network (vector) that i'm interested in carrying out some  on.  Predictably my GIS data is in a pretty terrible state. For example, there are a bunch of roads on the network that look like they join but do not. I've managed to fix some of this (on the surface at least) with the GRASS v.clean tool in QGIS.  My big problem though is polylines. In nearly every case I have long stretches of road that are stored as separate polylines. For example, a long trunk road, split into 5 or 6 separate lines even if they have all snapped together. Worse still in some cases these sections have been given different (or slightly different) road names and have no common identifying attribute. If I run the 'topology checker' in QGIS - it identifies these as 'pseudo-nodes'.   I now want to clean these pseudo-nodes and I was really hoping that there would be a (fairly) simple method of simplifying this network to allow me to run the space syntax analysis tools to actually give a meaningful output. Unfortunately the 'topology checker' only shows you where the errors are, I now need a tool to help me clean them. I had though v.clean from GRASS would do the trick but haven't had much luck. I have been looking at the suggested answers here:    There are a lot of reference to the sextante plugin for QGIS - though I have a feeling this has been incorporated into QGIS's tool now as the 'This plugin is deprecated!' according to the repository. If so, I can't find  "Extract endpoints of lines" and "Join adjacent lines". Does anyone know where I can find these functions - or alternatives?   p.s. using QGIS 2.10 on Ubuntu 14.04 - but open to suggestions of other opensource software/solutions: R; Python, GRASS 7, Open Jump etc.
Software gvSIG OA Digital Edition 2010 have tools topology for finding pseudo nodes in linear geometry. I set cluster tolerance 0.00002 and maximum number of errors -10000 for 20000 link count linear geometry. But unsuccessful result.   Are there any solutions that find pseudo nodes in free GIS software?   I need to layer pseudo nodes (one solution to this problem - to use tools topology of ArcInfo, but priority for me is to use free software). Linear geometry created several users in QGIS 1.8.0 in PostGIS (v. 2.0.1) database.  Add new image: 12 linear features with three pseudo nodes in A (line 4/5), B (line 6/7), C (line 9/10). Pseudo nodes should be points instead - two linear features with intersection in one point (node) should be one linear feature (line 4/5 - line 4, ...).  Is it possible to make a request in PostGIS, which will result in a layer of pseudo nodes?  Add new image of examples pseudo nodes: if I receive for linear layer point layer pseudo nodes (blue rects) I corrected following errors in linear layer: A - add missing geometry, B - snapped line in intersection, C - remove pseudo node.
I am trying to understand how complex numbers made their way into QM. Can we have a theory of the same physics without complex numbers? If so, is the theory using complex numbers easier? As asked in the title? Does the independence of two random variables $X$ and $Y$ imply the independence of $X$ and $X+Y$? If so, what's the easiest way to prove that? Is there a way to format a UTC time into any arbitrary string format I want in java?  Basically I was thinking of having some class take the timestamp and I pass it is string telling it how I want it formated, and it returns the formatted string for me.  Is there a way to do this? C++ performance of accessing member variables versus local variables Is it more efficient for a class to access member variables or local variables? For example, suppose you have a (callback) method whose sole responsibility is to receive data, perform calculations on it, then pass it off to other classes. 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In case I'm not being clear, here's some quick examples:  // use local variables class thisClass {     public:         void callback( msg&amp; msg )         {             int varA;             double varB;             std::string varC;             varA = msg.getInt();             varB = msg.getDouble();             varC = msg.getString();              // do a bunch of calculations          }  };  // use member variables class thisClass {     public:         void callback( msg&amp; msg )         {              m_varA = msg.getInt();              m_varB = msg.getDouble();              m_varC = msg.getString();               // do a bunch of calculations         }      private:         int m_varA;         double m_varB;         std::string m_varC;  }; Did Dolores Umbridge Have Any Association with Voldemort (or Death Eaters) before His Return? 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Convert ArrayList to String[] array