A set of ordered co-ordinates that represent the shape of geographic features too narrow to be displayed as an area at the given scale (contours, street centrelines, or streams), or linear features with no area (county boundary lines)

learn more… | top users | synonyms

4
votes
2answers
307 views

Draw two separate lines from A to B and B to A

I have an Origin-Destination table like this Origin Destination Value A B 10 B A 100 A C 120 ... For all the locations A, B, C... I have another table indicating their location (Lat and Lon) Is ...
2
votes
1answer
197 views

Sum line length with clip intersect? [closed]

SELECT sum(st_length(st_intersection(POLY.geom, LINE.geom))) AS sum_line_length... Is this function OK to calculate the sum of lines length? Wonder if it do the clip line where one line go from one ...
2
votes
1answer
3k views

How do i calculate line segment lengths within a polygon?

I have a layer with line segments and a layer of polygons (in this case, buffers around points). I need to create a new field for each polygon that contains the total length of all line segments ...
14
votes
2answers
1k views

How can I merge/collapse nearby and parallel road lines (eg. a dual-carriageway) into one single line?

I have a shapefile from OSM which contains all the roads within a city. Larger roads (like dual-carriageways) seem to have 2 parallel lines. I'd like to collapse / combine those into 1 line so I can ...
7
votes
3answers
2k views

Elevation profile 10 km each side of a line

How can I get an elevation profile for a band of terrain? The highest elevation within 10 km (on each side of the defined line) should be taken into account. I hope my question is clear. Thank you ...
0
votes
0answers
282 views

CAD Contour Lines to ArcGIS Attributed Polylines

I'm having a 'CAD to GIS' issue. I have a dwg file which contains large number of contour lines that have been split by labels. I need to import the contour lines from CAD to GIS so that they contain ...
6
votes
2answers
578 views

How to create line with exact same length over and over again?

I need to draw 30 meter lines in specific places. Ctrl+l is too annoying to do everytime. Is there a easy way to define specific same length for a line that I need to draw many times?
6
votes
1answer
459 views

QGIS line style

I found the latest QGIS has a great tool to create complex styles, however looks like one small but very useful thing is missing, or I can't find it. I'm trying to create a line style something like ...
1
vote
0answers
351 views

Creating points along lines? [duplicate]

Possible Duplicate: How to create a point along a line given distance How to create equidistant points in QGIS? I have some road survey data and each line has an individual value and ...
3
votes
1answer
172 views

digitizing (tolerence) error in line data

I have designed a large number of boundaries. For accuracy, I took lines in patches from different data sets and merged them into one. Now I want to turn them into polygons from lines. I every second ...
11
votes
2answers
519 views

Moving points onto lines (~neighborhood)

I do have two vector layer, of which one is a point layer based on "events" by remote sensing and the second one is a line layer from local research. In my case these are earthquakes and tectonic ...
2
votes
0answers
62 views

Strange line appearing

I have this line in my project's layer which i cant make disappear: I hope you can see it. In QGIS is much more visible. An it also appears on the print composer. Any suggestions would be very ...
3
votes
0answers
115 views

Why doesn't Polygonizer copy the line ids to my polygonized shapefile?

I am trying to convert a line shapefile into a polygon shapefile using Polygonizer plugin, and when my new polygons are created all the cells in my id field are "Null", although I have clicked "copy ...
4
votes
1answer
247 views

How to extract most probable flow line from multiple lines?

I have to apply uncertainty principle to computing flow accumulation using Monte Carlo method. I generate raster with random numbers which represents mistakes in creating DEM. Then I apply those ...
3
votes
1answer
255 views

How to create a line with start and end points which are in another layer in QGIS?

In my map, there are lots of points in layer A. I want to make a line layer B and I want to make start & end points of lines snapping to points in layer A manually. Can I use points of layer A as ...
3
votes
1answer
320 views

How to connect particular sets of points with (poly)lines?

I think my problem is quite easy to be solved by the most postgis-users, but i am a bloody beginner: i have a timestamped point-table representing GPS-tracked places of different cars. To distinguish ...
1
vote
1answer
473 views

CssParameter stroke-width min max value Geoserver

I wonder if there is a minimum value for the stroke width parameter since I've a LineSymbolizer with stroke 0.1 but i want it to be thinner so i change the value to 0.05 but i dont see any difference ...
6
votes
1answer
579 views

How to connect places (points) without crossing lines?

I have two sets of data. One with placemarks represented by blue dots in image below, and another set of geographic data with lines represented by grey lines. 1) For the first point in drawing, I'm ...
3
votes
2answers
2k views

Compute Angle of a line in conventional bearing

I am trying to compute angle between two lines (line segment) using ESRI (ArcGIS, JS) in conventional bearing (Eg: N29'E) I am using Add Toolbar to draw a line segment where point A is a fixed point ...
6
votes
2answers
2k views

How can several vector layers have different controls, using Openlayers?

Using openlayers I have two vector layers. One layer is called lineLayer consisting of vector lines, and the other is called pointLayer consisting of points. When I hover on the lines I want to be ...
2
votes
2answers
329 views

Joining lines in MapInfo that won't be split by disaggregate?

I have just run a disaggregation a .tab containing just lines and found I have a few with duplicate IDs. However when I zoom in these lines appear to be connected. Is there any way to join these ...
5
votes
2answers
4k views

How to Partition Line into Segments using ArcGIS for Desktop?

I have a shapefile of U.S. states. I extracted the boundary between two states, resulting in a line segment. For example, the boundary between Georgia and North Carolina. Is there a way to further ...
1
vote
1answer
1k views

Drawing a Straight Line Between Two Polygons on a Map and Listing Which Polygons It Passes Through

I have a shapefile of United States counties. I have two counties that I would like to highlight. I would like to draw a straight line distance between them. By straight line, I mean, if you were ...
5
votes
2answers
219 views

Grouping lines together to form one line after a distance threshold is met: ArcGIS 10

I have lines on a map showing the most direct way from point data to the coastline (polygon). I would like to group the lines if they are close to each other by a distance that I can set. Where the ...
6
votes
4answers
296 views

How to avoid holes in polygons from lines?

I am trying to convert a dataset of lines that contains the coast of New Zealand into a big polygon. However using the vector -> geometry tools -> lines to polygon command in Quantum GIS results in a ...
4
votes
3answers
1k views

Finding centrelines from polygons?

I was wondering if there is a way to create centre lines from polygons in QGIS? I have a polygon layer, but ideally need the centrelines as a separate file. Thanks, Alan
1
vote
4answers
628 views

How to find the center point of MULTILINESTRING?

How to find the center point of MULTILINESTRING, which lies on the multiline?
2
votes
1answer
81 views

I made a Relationship Class(1-M). Its a street X our Address table. I can´t split the street. How to fix it?

I have a table "Addresses" and the Feature "streets". The feature "Streets" are lines. I need to do a relation with this table with this feature. What I do? I tried built a "relationship class". The ...
5
votes
1answer
190 views

Given 2 LINESTRINGs with common point, how to extract common point?

I have 2 LINESTRING geometries. I know both share a common point. Using PostGIS for Postgres, what is the cleanest way to extract the common point? Example with illustration: How do I extract the ...
0
votes
1answer
282 views

Change line selection display in MapInfo

can someone help me with a MapInfo query. Is it possible to change the display MapInfo uses when selecting lines? Atm I can be often difficult to see selected lines easily as the lines I am using are ...
2
votes
1answer
213 views

Connect points along bathymetry contours

I have a table with start and end point data in each row and need to convert them into lines, but I would like something other than a straight segment. Ideally, I want to connect the points via a ...
4
votes
2answers
498 views

How to find isolated geometry/attributes in road network?

I have a road network with paved/unpaved status in attribute table. This road network don't must contain isolated paved geometry. There are any solutions find isolated geometry in GIS software ...
7
votes
2answers
236 views

How to connnect two lines with different width so it looks good?

Simple question, how do you create a symbol with or without representation to connect two lines with different line width so it looks good? I need to have a smooth transition between the lines, ...
1
vote
3answers
539 views

Divide Line Into Sections Using Points Offset from It

I have track (line) and milemarkers (point). Each point is offset by a different distance. Is there a way to find where each point would intersect the line if going perpeniduclarly out from the line? ...
2
votes
1answer
259 views

merging TIGER Line shp files for better labeling in ArcGIS

When working with TIGER line shp data at county level scale the labeling of roads, rivers, railroads, etc. is cumbersome due to all of the tiny line segments. Merging the dozens of segments that ...
1
vote
3answers
4k views

Show pop-up where user clicked in OpenLayers

How to change this example ( http://openlayers.org/dev/examples/select-feature-openpopup.html ) so that when the user clicks on a line (feature) pop-up display where the user clicked? A few days ...
4
votes
1answer
148 views

How best to map lines based on multiple attributes?

I need to plot lines onto a map to display road quality. I'm already using colours to distinguish between different road conditions, but I also need to display another factor - the survey origin. ...
2
votes
1answer
1k views

Basic User Questions: Tracing a Border in QGIS

The project: I'm plotting a dilapidated cemetery, I'm using GPS waypoint data to plot the headstones in QGIS. The map I'm making is to show the orientation of the graves, and who is in them. I ...
3
votes
1answer
709 views

Splitting lines at a specified distance

Does exist some plugin with it is possible to Splitting lines at a specified distance in Qgis?
6
votes
1answer
511 views

Filling a polygon with lines using Postgis

i need to calculate a specific distance in an area. The distance is calculated from parallel lines in a polygon, And i need to find out how many parallel lines (with x meters distance to each other) ...
3
votes
3answers
436 views

Selecting polygons with a minimum internal straight line value - ArcGIS 10

I have a map of polygons representing forest stands. I am trying to sort through them to find those polygons that have a minimum internal distance of 200 m in a straight line (my field sampling will ...
2
votes
1answer
372 views

How to move a Point perpendicular from nearest Line?

I want to move Point perpendicular from nearest line or polygon, and the question is how to do that? example, I have points (house number) near roadbed, and I don't want them to intersect roadbed ...
3
votes
2answers
366 views

Housenumber(point) angle from line (street)

using arcgis 10 with Point data (Housenumber without angle attribute) and line data (street without angle attribute) I want to create housenumber labels from point with correct angle from nearest ...
2
votes
1answer
518 views

editing existing lines

I have a quick editing question. I have a main line (street) from which I want to extend other small lines to reach some points (manholes), but I want to keep just one feature (the main line). I ...
1
vote
0answers
282 views

ArcGIS10 Split Line at Point Failing due to Dataset size

Im having an Issue with my Split Line at Point tool. Seems to run if lucky for 700 entries before arcmap/arccatalog falls over. Debugging of the errorlog has produced nothing. The total size of the ...
6
votes
4answers
18k views

How to create polygons from lines?

I am trying to create polygons from a line layer of lots and concessions (large blocks of land in rural areas). The lines are mainly grid style as they intersect mostly at right angles. I need to ...
4
votes
1answer
3k views

Create point in intersections of two layers

I have two layers. One of them is 'Road_line' and another one is 'forest_shape'. I want to create a point layer that has points in intersection of that layers. I couldn't find any tools for it. Could ...
8
votes
2answers
819 views

Creating a line (closest vertex to line)

I am working in reorganising our utility data. Two years ago, we have started collecting Private Service water line. We still have a lot of them to extract from old Record Drawings. I was ...
6
votes
1answer
872 views

Is there a way to automatically snap loose points of lines to close by vertices with Quantum GIS?

I have a vector layer of lines that were drawn with the snapping option off. I need to have them snapped but, there are hundreds of lines. Is there any solution to do this automatically or ...
3
votes
2answers
2k views

Workflow for creating line features between two coordinate pairs in QGIS

I have a table of stream reaches with xy coordinates for their respective tops and bottoms. I'd like to convert the table to a feature, using the xy coordinates as the endpoints of the line. Any ...