1
vote
2answers
55 views

How to activate snapping for layer you are drawing polygons in?

I want to draw multiple polygons in a layer that have boundaries without a gap, so I activated snapping for that layer. But it doesn't work. For other layers it works fine.
1
vote
1answer
79 views

Creating new lines along specifically selected existing lines using QGIS?

I have tried to find a solution for this everywhere, with no result... My problem is that I want to be able to manually draw a line that automatically snaps to a line (creating an exact copy of the ...
0
votes
0answers
19 views

How to cut a polygon without snapping to a vertex?

I am familiar with editing polygon files in QGIS version 1.8. I have recently upgraded to version 2.0 but there seems to be a difference in the way it processes cuts. I used to be able to cut a ...
0
votes
1answer
67 views

How to avoid snapping errors in QGis?

I am using QGis version 2.2.0 and I set the snapping option to the vertex, with a tolerance of 1.5 meter. When I draw a new polygon next to an old one, it seems like the vertices are automatically ...
0
votes
0answers
48 views

Alternative to Snap (Editing) in QGIS/MapInfo?

Is there any alternative to Snap (Editing) in either QGIS or MapInfo (user-made tools), or another way to do this in ArcGIS without an advanced license?
2
votes
0answers
128 views

Snap points to line and calculate chainage using Open source GIS

I have a line layer (representing a pipeline) and a points layer (representing valves) and I would like to calculate the chainage of the valves along the pipeline. I assume that I would first need ...
3
votes
1answer
118 views

how to snap two line vertex in two different layers used in QGIS

I want to snap between two poly-lines from 2 different layers (Layer1 in Brown and Layer 2(postGIS layer) in Pink color- ), but my snap option don't work. I have changed the tolerance to different ...
1
vote
1answer
98 views

QGIS snapping not working for me

I am new to QGIS, and this is a very basic question. I made a new polygon layer, to trace cadastral boundaries off a raster map. I want the polygon nodes on adjoining acreages to snap together. Some ...
2
votes
0answers
21 views

automatic snap line to line [duplicate]

I need to automaticly overlay/snap the red line (gps-track) exact on the lines of my roads-shape. Is that possible?
1
vote
1answer
226 views

How to change the color of red edit-polygon or purple snap-confirmation?

I'm having trouble seeing the purple or pink snapping confirmation when drawing a polygon because the temporary polygon is red (QGIS 2.0.1). Also the vertices in edit mode are also red. I looked ...
2
votes
1answer
214 views

Tracing Boundary Around a Polygon Shapefile in QGIS

I'm looking to create a boundary around this shapefile of street blocks to have show the city limits in QGIS. I tried this solution, (Settings > Snapping Options and enabling the "Avoid Int." ...
1
vote
0answers
87 views

how to avoid Intersection of polygons via python code

i am using QGIS 1.8 and i can set the check box in Setting\Snapping Options "Snapping and Digitizing " dialog to avoid polygon intersections and enable topological editing but i am looking for a way ...
10
votes
3answers
2k views

How to snap lines to points automatically?

I have two vector shapefiles: One file is points representing manholes and the other is a polyline file representing pipes leading to and from the manholes. I need to snap the lines within a ...
1
vote
1answer
485 views

How to fix the “Snap tolerance” error message in QGis?

I am trying to use the "Delete part" tool on a shapefile. While I am starting to use it, an error message shows up : "Could not snap segment. Have you set the tolerance in Settings > Project ...
3
votes
1answer
3k views

How to enable “snapping” in Quantum-GIS while drawing polygons?

I tried to draw polygons in qgis-1.7.0 and I somehow can't find or failed to find the "snapping" option. I'm used to ArcGIS-10.0 where you have some snapping options, like placing points of polygons ...
5
votes
2answers
5k views

snapping polygons and lines

I recently downloaded QGIS on a Mac OSX 10.7.4 (lion) and purchased a master map shape file, of a particular area. I am trying to divide it into polygons following features on the master map vector ...
1
vote
1answer
163 views

QGIS - WGS84 to BC Albers reprojection no curved lines, any idea why? How to snap a line to a point?

I am trying to learn a bit about QGIS. So I thought I would drop in some layers of my Province and then recreate some points representing the BC Albers Central Meridian, and the two standard ...
6
votes
1answer
816 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 ...
11
votes
1answer
741 views

Snap line layer to network in QGIS or PostGIS

I have GPS data I've taken of bus routes, and now I'd like to snap it to my road network. Both layers are line layers in a PostGIS DB. I'd like to use either QGIS or PostGIS, but if I have to go with ...
21
votes
7answers
15k views

Removing small spaces (slivers) between polygons?

I have a set of polygons representing administrative districts. The districts were digitized by hand, and there are small spaces (slivers) between polygons where the polygons should be touching. How ...