A geometric element defined by a pair of x,y coordinates.

learn more… | top users | synonyms

0
votes
0answers
9 views

Points nearest to polygon: nearest to edge of polygon or centroid?

When using ArcGIS and performing a Spatial Join of points to polygons, there is an option to choose the closest point. Is the point that is chosen closest to the edge of the polygon or to the centroid ...
1
vote
0answers
28 views

Point to raster: QGIS vs ArcMap

I have an equidistant point grid (0.5m) and created a raster from it in QGIS and ArcMap, with different results: QGIS: Raster -> Conversion -> Rasterize Result: raster, with points in the top left ...
0
votes
1answer
53 views

How do I measure the distance between two points within a country arcmap

I have two shapefiles with points distributed over the whole world. I would like to measure the distance (like the crow flies in km) from each point in shapefile 1 to the closest point from shapefile ...
3
votes
1answer
5k views

How to add points to a point vector layer - QGIS

I have a point layer with multiple data points in QGIS, but I want to add some extra data points to it and adjust some info that we missed because the ground was wet and we needed to go around it. I ...
0
votes
0answers
21 views

Order a list of points to make a polygon with smooth outer border

I have a function that pulls some lat/longs from a Database and then I put those values in a polygon to see it's shape. The problem is they are so random in position and direction from each other that ...
0
votes
2answers
21 views

Create point on a line with given distance from end in PostGIS

Does anyone know how to create points along a line (MultiLineString geometry) with a given distance in PostGIS? I'd like to create points at a regular distance over a line, which represents a ...
0
votes
0answers
28 views

Point Density produces enormous size rasters [on hold]

I am trying to analyse density of points that represent crime locations in Northern Island. I have shape file containing 92k points. My data is in projected coordinate system (BNG). I tried to run ...
-1
votes
1answer
16 views

Converting start/end easting/northings to a single point for visualisation

I have eastings and northings for the start and end of 5m sections of the UK railway network. I want to convert these points to a central point between the start and end so I can visualise the ...
0
votes
0answers
21 views

Why does the “local maxima” module in SAGA GIS put so many “maxima” points on lakes and plains?

SAGA GIS puts too many maxima points on plains and lakes. Why does it happen? Is there a way to avoid this? It's not really a big problem (the value is correct) except for the size of the SHP files in ...
2
votes
1answer
540 views

Postgresql view with Point geometry returns QGIS error “(the_geom) sql = is an invalid layer and cannot be loaded”

I want to create a Postgresql view using point data. When I create the view, the geometry_columns table updates appropriately. Attempting to load in QGIS produces the error “(the_geom) sql = is an ...
5
votes
1answer
312 views

QGis 1.8 fails to rotate point geometries with rule-based style

I have to do some visualizations in QGIS (1.8.0) and up to now I've been very happy with the new Dialog "Layer Properties -> Style", using the rotation-field to rotate Point-Geometries visualized by a ...
2
votes
3answers
472 views

Draw line between points from multiple datasets

I have 2 point datasets and want a tool or script to draw a line between all points in one dataset to all the points in the 2nd dataset. Is it possible? I have tried ESRI "Point Distance" and ...
4
votes
3answers
766 views

How to join number of point features into attribute of nearest line segment using ArcGIS Desktop?

I have point shapefile with lot of attributes, that represent road accidents and line shapefile with highways. What i want is to join attribute into line shapefile with value, that represent number of ...
0
votes
0answers
32 views

Extending line by adding point at end of it using QGIS?

I'm using QGIS 2.8 to modify a line. I need to add a point on one end of this line, and then move this new point further away, leaving the original end point in the same place. I can manage to create ...
0
votes
0answers
13 views

Point data aggregation for choropleth

I have a sizeable amount of geotagged point data (>1M) and am looking to create a choropleth map of point data density based on boundaries I have in a shape file. I've added this to a fusion tables ...
0
votes
2answers
255 views

How to extend polylines to the nearest point

Hi could anyone tell me a way of getting my polylines to search for a point within a certain number of meters of their start/end points and extend to it? edit: There was some broblem uploading a ...
1
vote
0answers
39 views

Loading lots of points on leaflet through time slider.

I'm trying to add more than 13 thousand point using Time Slider plugin, but as you can imagine the loading process of all these points puts a heavy burden on the map. Even the slider start to get ...
3
votes
1answer
65 views

Using arcpy to find geometry within another feature

In Arcpy, I would like to start with a point and then using its geometry method to find out if it is inside my polygon feature (Urban Areas) deeper than the buffer distance. This is a follow up to ...
0
votes
2answers
55 views

Points on Map overlapping/covering city and town names

I have a map with many points, these points map incidences of landmine accidents in Colombia. There are thousands of points and cover up parts of city and town names, in some cases the entire lables ...
1
vote
1answer
26 views

Merge 2 Pointlayers with same coordinates but different attributes in QGIS?

I have two layers with points who have exactly the same coordinates but different attribute fields. I would like to merge the tow layers so that I only have one point at each location who has the ...
2
votes
1answer
383 views

How to obtain closest point of point over polylines layer in PostGIS 1.4 (without st_ClosestPoint)?

I´ve got a polylines layer (pipes) and a points layer (valves) and In Postgis 1.4 I would like to obtain the closest points but exactly on the closest polyline. In other words, i need to locate each ...
6
votes
3answers
361 views

City shapefile for free

I am looking for a simple point shapefile which indicates where the cities of the world are. I cannot seem to find one which is free of charge and meets my requirements. Ive got this one: ...
1
vote
2answers
90 views

How to “select by location” certain points

I have a small problem - how to select the points on the line but not select the points at the intersections of lines using "select by location"? Illustration below. I am using ArcGIS 10.0
2
votes
1answer
69 views

Feature is a point or polygon

Im new to GIS and am just curious if there is an instance where a feature can be a point in one map and a polygon in another map and vice versa?
0
votes
0answers
18 views

Temporal correlation of point data

Case: I am working on a project where we are trying to study the correlation of municipality water leaks with diseases, we have a geo-referenced database of water leakage reports and disease reports, ...
3
votes
1answer
32 views

Analyzing hot spots using point attributes?

I'm interested in looking at where hot and cold spots of certain social indicators (such as poverty, housing characteristics, urban sprawl, etc...) are in coastal communities along the East Coast. I ...
2
votes
1answer
41 views

Create random points in ArcGIS on a polyline in a polygon

I am trying to create 100 random points, 1 within 500m of 100 points I already have. I have created a buffer and can easily create 1 random point in each, but now I want those points to lie on a ...
4
votes
2answers
109 views

How to randomly move points?

I have a feature class with a large amount of points. My purpose is to randomly move these points to see what happens as a result. Are there specific tools or Python programming methods to accomplish ...
3
votes
3answers
134 views

How to convert points to lines?

I want to convert these points to lines, however they are not sorted sequentially along a line (by ID or FID), i.e. the converted lines zig-zag across the obvious trail of points. How can I join ...
10
votes
4answers
1k views

How to model a graveyard - one point per deceased or one per grave? [closed]

This is a continuation of my previous question about our project on how to economically get away with the implementaion of a graveyard in a GIS system… On the graveyard we can find Regular ...
0
votes
2answers
37 views

How to convert GeomSHP to WKB

I have imported a point shapefile called site_locations.shp into a personal geodatabase. Now I'm trying to retrieve the data from the database using SQL: dbpath = ...
1
vote
1answer
178 views

How to generate random points with minimum distances between points in multiple polygons

I am looking to create random points for a random stratified survey. There are three different categories being surveyed; for each, I have a single shapefile, each containing a number of polygons. I ...
3
votes
1answer
156 views

How to map flood areas from a set of points containing surface and height of water?

I am working on the damages made by the typhoon Haiyan. I use QGIS 2.0 with extensions and toolbox, and MapInfo. I have vectors, rasters of the place. I want to map the flood area along the ...
1
vote
0answers
10 views

To filter the wrong data of point positioning

I have collected GPGGA data by Novatel OEMV receiver in static single point mode. I have so much data (GPGGA format) and I want to get the static point axis by averaging all data. But some of the data ...
1
vote
0answers
31 views

Sample points based on underlying polygon attributes

I have a point shapefile and I would like to sample those points (just like the "Sample" tool allows points to sample underlying raster) to receive a table with underlying polygon values (interested ...
2
votes
0answers
40 views

How to find the concave hull for a cloud of points in 3D space?

The existing algorithm for convex hull is not able to capture the feature for a set of 3D points. Moreover, I found few mathematic tools have this function to obtain the concave hull and their ...
0
votes
1answer
38 views

How do I calculate the latitude of an end point given a start point, bearing, and longitude of the end point?

I have a line that crosses the 180. Given the bearing from Point A to Point B, how can I determine the latitude of the point on the line, given the longitude of the end point to be -179.9999? For ...
1
vote
1answer
50 views

Why did my data points shift position?

Here is an example of my issue: There are two point layers displayed in this image: The yellow dots are my currently used layer with the most updated data. The green dots are legacy data from when ...
0
votes
0answers
22 views

Raster to point: 10 rows in the attribute table per 1 point

I have just made Raster to Point operation. In the output, if I select a point on the map, in the attribute table appear I have just selected 10 rows. How is it possible? Where, in the Raster to Point ...
0
votes
0answers
25 views

New value in attribute table for big amount of points

I have got a huge amount of points. I need to change their value according to thier current value. Ex. I have got 4000 points. 1000 with value 7 and 3000 with value 8. I have to select all those 1000 ...
1
vote
1answer
54 views

Select points near polygon in Postgis

I'm trying to make a spatial query, but I think something is wrong with it: I have two tables, places (point) and cities (polygon) When I try to get the points within 500m to one point, there is no ...
0
votes
1answer
16 views

Can A PLugIn in QGis let me cut polylines where the points of another shapefile are [duplicate]

I want to know if there is a plugin/tool in Qgis, that let me cut lines of a shapefile where the points of another shapefile are. Thanks in advance!
8
votes
2answers
1k views

How can I create random points along a polyline in QGIS?

I am trying to create random points along a polyline shapefile in QGIS. Basically, like the 'random points' tool in 'research tools' but for polylines instead of polygons. I have tried converting ...
1
vote
1answer
3k views

How to find nearest point for each point in current layer using ArcGIS Desktop?

I have a point layer and want to know the distance of nearest point of current layer for each point in the layer. I found some tools in ArcToolbox about it , but they need two layers for input and ...
2
votes
0answers
135 views

Near/Spatial Join picking wrong polyline segment as closest? [closed]

I have a set of points near a street centerline. I need to find the perpendicular point on the street centerline, and use their x y instead of the GPS information of the original points. I tried Near ...
3
votes
0answers
35 views

Space time analysis. Finding spatial patterns (cluster&disperse) over time in point data sets

I am trying to describe/find statistically spatial patterns in a point data set of industrial sites. The points feature apart from their location, a date for their opening, a date for their closure ...
1
vote
0answers
46 views

How to calculate the average point spacing for a layer of points in QGIS?

I have a set of points and want to calculate the average point spacing for further analysis. ArcMap has the 3D Analyst Point File Information for this but I'm searching for an alternative in QGIS. ...
0
votes
1answer
72 views

ArcGIS Javascript Spatial Query with Lat Lng or X Y?

I am using Google Maps on the front end as all I need on this view is to show the points. When user clicks on the map in the view, it selects a point hence giving out lat and lng. I am trying to use ...
0
votes
0answers
30 views

How to convert points distribution toward surface information?

I'm working with QGIS 2.6 I have a points layer representing different bus and train stops. I applied a categorized symbology; each colour represents a class of value (field regarding time access ...
3
votes
2answers
96 views

Can't export customer's shapefile to latitude and longitude

I'm very new to this application so bear with me. I hope that I am missing something very elementary. I have a shapefile supplied by my customer. I need to get the latitude and longitude for each ...