So I just used v.split to create shorter segments (with just 2 vertices) of my contour lines. I was left with about 22000 lines but, when I open the attributes table, I find no more than 45 entry lines.  How can I make it so I have a unique ID for each of my new line segments?
121261
How do I get for each  point an ID in the database (DB).  So far I splited the line (each 10m) but it returns only one DB entry for each original line.   v.db.select line cat|Id|Name 1|1|Line 1 2|2|Line 2  # split the lines every 10m v.to.points in=line out=line_points dmax=10  # check the result v.db.select line_points cat|Id|Name 1|1|Line 1 2|2|Line 2   Each point should have its own DB entry. The result should be:  v.db.select line_points cat|Id|Name 1|1|Line 1 2|1|Line 1 3|2|Line 2 4|2|Line 2     Workaround: So far my workaround is, to export (v.out.ogr) the points as shape and import (v.in.ogr) it again. Then each point has his own ID. But there must be a smarter way to do that!
106338
I want to make various copies of a graph in tikz. The graph I want has 10 vertices. But only has the edges between the vertices a_i,a_(i+1),t,b.  I would like to automatically create 8 copies of this graph. and draw them. I just don't know how to code it. Here is my current code, but it adds all of the edges to the same copy of the graph:  \begin{tikzpicture} [main_node/.style={circle,fill=blue!20,draw,minimum size=2em,inner sep=3pt]}] \node[main_node] (8) at (0:0.5) {b}; \node[main_node] (9) at (180:0.5) {t}; \foreach \x in {0,1,...,7}     \node[main_node] (\x) at (360/8*\x:2) {$a_{\x}$}; \foreach \x in {0,1,...,7}{     \pgfmathsetmacro{\y}{int(mod(\x+1,8))}     \path[draw,thick] (\x) edge node {} (8);     \path[draw,thick] (\x) edge node {} (9);     \path[draw,thick] (\x) edge node {} (\y);     \path[draw,thick] (8) edge node {} (9);     \path[draw,thick] (8) edge node {} (\y);     \path[draw,thick] (9) edge node {} (\y);    }   I want each of the edge sets to be drawn seperately.
46843
I want to divide this model into separate pieces to prepare it for the next stage of a project. The divide needs to be made down a curved line (which I hope is visible in picture).  ,   I figured out how to cut it down a straight line a couple weeks ago, but apparently a curve is a different beast. Is there an operation for this, or do I have to manually make a bunch of straight cuts (or something equally painful)?
110406
I have my model and in the info bar its show this   May I need to know how many polygons it has, but  there is no option to find polygons. Verts, Edge and Faces nothing polygon option there. In the website its say that the upload limit is 400,000 polygons. I did not get over that limit or how many polygons my model has?
61084
What is the number of rectangles that can be obtained by joining four of the 12 vertices of a 12-sided regular polygon?  The thing that I've tried is to find out at what intervals should I connect to vertices of the polygon so that a rectangle can be formed. But that didn't seem to help at all .
44998
I have two shapefiles, Point and Polyline. I'm trying to populate my polyline layer with the point data ID (systemID) where the lines start to where they end; eg. create two columns (from and to). The lines already have flow direction assigned to them. I am using ArcHydro tools but Arcpy is also fine.  In ArcHydro I have tried using Attribute Tools > Generate From/To Nodes for lines but it creates values for To and From that are not from my point data. My other alternative was using Feature to Vertices and joining the result to my point data table to get the systemID. But then I would have to update the polyline layer as well. I am sure there is a easier way of doing it.  Note: not all the lines have points at the vertices, blank values are fine for them.
47910
Hello to everyone again,  I'm looking for an addon or a short cut to fill fast and simmetrically a NOT FLAT surface that needs to be closed with vertices. Doing it manually it takes a lot of time. I tried to do CTRL F and then Grid fill,but it didn't work. Neither F key works. Check the attached screenshot. thanks.
92963
I have a river shapefile that I need to break up into 1-mile increments.   The polyline is 53 miles in distance, so I should I have about 53 mile markers as a result.   I have tried the Divide tool, but then it doesn't show if it did anything afterwards.   Should I manually use the Split tool to split the river at every mile increment, or is there a better way to do this?   I am creating a river mile map.
81982
Is there a way I can separate the vertices on the the segments evenly without moving the end points? I would like for the vertices to maintain the current curve.
32200
I have a shapefile containing contour for a large area, and I want to split it into different shapefiles each covering a 1KM X 1KM area. I have already created the required Grid shapefile in QGIS.  How do I now split the contours using the created Grid?  I am searching for something equivalent to the  in ArcGIS.
38290
I need to create a shapefile with crossed streets. I can't split the lines to number each segment with the house number ranges.
104911
This doesn't seem complex, and I'm not a beginner but can't figure it out or find answer online.  I want to be able to trim a series of lines to fit in a complex shape (lay the shape over a group of stroked paths and trim them so only segments that are within the shape remain). I want actual truncated line segments left so that I can apply strokes, widths, profiles and brushes to what's left.  I understand clipping masks (but they don't leave new endpoints for width/brushes) and envelopes (which bend/distort lines to fit) and have tried all of the pathfinder options with no luck. I can of course just use scissors and cut-cut-cut at each intersecting point, but this isn't a one-off shape it's a process that I want to be able to repeat often across several works.  Essentially it should just be a clipping mask that cuts/deletes line segments outside it and leaves actual line segments (not shapes) behind...seems simple and an obvious function, but I'm stumped. (I'm in CS6)  Thanks for any help!
54186
I have a line shapefile and a point shapefile, and   the line has just one segment     and its attribute table,     the point shapefile has points near the line above, not on it     and the close look,    I want to use ST_split to split this line at locations which are nearest to the points I want to get the original line with more segments(because being split). For example, find the location on the line, which is the nearest to the point, and split the line at this location(star).    I loaded this line shapefile into PostGIS and here's my SQL code in PostgreSQL,  select ST_AsText(ST_Split(ST_GeomFromText('LINESTRING(0 0, 247907.60 2746404.62, 200    200, 400 400)'),        ST_Line_Interpolate_Point(ST_GeomFromText('LINESTRING(0 0, 247907.60 2746404.62, 200 200, 400 400)'), 0.2)))   And I checked the table of this line, it wasn't being splited.  Where did I make mistakes？ I am new to use ST_split, please give me any suggestion, thanks.  I am using QGIS 2.2, PostgreSQL 9.2 and PostGIS 2.0.4 under Windows 8.1 x64.    Update#1  @simplexio, I used your code,  select ST_Line_SubString(ST_GeomFromText('LINESTRING(0 0, 247907.60 2746404.62, 200 200, 400 400)'), 0 , 0.200 ) as geom into split_line ;   and got a new table named split_line,    But as I used the following code you posted,  SELECT ST_Line_SubString(line, 0, ST_Line_Locate_Point(l.line, p.point)) as from_start_geom,        ST_Line_SubString(l.line,ST_Line_Locate_Point(l.line, p.point), 1) to_end_geom, l.line_id, p.point_id FROM lines l , points p  WHERE l.line_id = 1 , p.point_id = 1   I got a syntax error,    How to fix this and move on？ And where should I assign the line I want to split as input of st_split？
59071
I have a bunch of points on a QGIS map. Each point is a unique sampling event. However, some of these points have been sampled multiple times but there is no common identifier in the attribute data to determine this. The only way we can see this is by looking at the map and seeing points very close to each other.   I am wondering if anyone has a method to assign points within a 150 meters of each other a common identifier?
79616
I'm trying to create a points in the middle of polylines. The data is now in the form of shapefile. Is there an easy way to do this?
64736
I have 4 multipart polyline shapefiles (download a sample dataset ).   The geometries are identical, except for the length of segments in each shapefile. They represent 4 variables describing an identical shoreline. From these 4 overlapping polylines, I would like to create a resulting polyline that has segments for each unique set of the 4 input lines.    My approach was to use an intersect. This, however, breaks down when I try to run it on 4 huge feature classes.  My question is whether there is a more efficient way to combine polyline attributes stored in separate layers. I thought a union would be good, but it only works on polygons. Spatial Join seems inefficient, as I would end up with many to many joins for a single segment. Turning the segment end points into a point layer, then splitting the line at those points?  I have access to arcpy, PostGIS, and shapely.  Has anyone had experience doing this before on large datasets? Is there a more efficient way to store these variables?
51188
I want to connect all points in a point feature with every possible line segment using QGIS. For example, how a pentagon has five points with ten line segments connecting them all to form a pentagram inside. Alternatively phrased: How do I make spokes when all the points are hubs? I don't care about the order, I just want every connection between two points as one line each. Is there a tool or script that can do this in QGIS? This topic () is the closest to what I want but the plugins are no longer supported.