Questions tagged [point]

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

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2
votes
1answer
266 views

Comparing point pattern and raster data?

I have a simulated data set showing distribution of a certain habitat type as a point pattern. Then I have a empirical data set but there the format is raster. The two datasets are covering the ...
2
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2answers
3k views

OpenLayers: how to save added point in server side

I'm new in OpenLayers. I have simple application, which use a picture as map, on this picture users can add, move, or delte point, and then save. I have implemented adding, moving, deleting ...
2
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2answers
653 views

Visualizing updating lines of bearing from point?

I'm working on a project where I need to visualize a constantly updating line of bearing from a point, based on degree of rotation around that point. My plan is to design a line feature with an ...
2
votes
1answer
1k views

Snap to closest polyline from point

I want to create a new layer/shapefile, containing polylines that represent a connection to a grid. I have a layer of points and a layer of polylines (see picture below), based on this I want to ...
2
votes
2answers
686 views

How to automatically convert dots on paper maps to vector points?

I have several paper maps with dots that I need to convert to vector points. I was hoping to get some suggestions on how to accomplish this without recreating each and every point by hand. I know ...
2
votes
2answers
117 views

Best site location to plant trees

I would need to find out which is the best location to plant new trees on a plot of land I already have. I´ve created a vector file for the plot(polygon) and another one (points) to indicate the ...
2
votes
1answer
973 views

Error for point.in.poly function in the spatialEco package in R stating arguments imply differing number of rows

I am using the point.in.poly function from the spatialEco package. When I ran my original point shapefile and polygon shapefile, I got this error message: arguments imply differing number of rows: ...
1
vote
2answers
7k views

How to select all points within a circle in PostGIS?

I have set of points in a PostGIS Table (Type Geometry). Now, I need to filter points that lie in a circle with a center (C) and radius (R)! I expect C to be of type Point or Coordinates.. R to be ...
1
vote
1answer
678 views

Calculating distances and relationships between point land line vector layers using QGIS?

I have two vector layers. One lines and the other points. I am trying to find how far dots are apart from lanes, on average? I am thinking about setting a buffer around the lines, and finding how ...
1
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2answers
835 views

QGIS 2.0 Automatic generation of a vector layer out of a point layer

I am an environmental engineer and the aim of my QGIS 2.0 project is to visualize the results of a sewage water system inspection. In a first step I included the hoppers from a csv file and added a ...
1
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2answers
675 views

QGIS point sampling tool really slow for polygons?

I have a large field of randomly distributed points (100,000 of them to be precise), and I'd like to get values for a variety of raster and polygon coverages for each point. I've been using the QGIS ...
1
vote
1answer
192 views

Determine on which side of a line points are located

I have a point shapefile (point.shp) and a line shapefile (line.shp). I want to determine on which side of the line each point is located. The best would be to use a pyqgis command to add a field to ...
0
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1answer
1k views

Determining if point on boundary using shapely? [closed]

I'm new to Python, and I want to test if a certain point lies ON the (boundary) of a polygon - not inside, not outside, just if it's on the boundary. The points and polygon already defined polygon = ...
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4answers
1k views

How to Remove Multiple Labels for Stacked Points? ArcGIS 10.2.2?

I have a point feature class, in certain areas there are stacked points. These stacked points are accurate. However, when I label the points I am getting a label for each point, which is okay for each ...
12
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4answers
2k 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 ...
7
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4answers
2k views

Create mid point from line layer

In QGIS I am trying to create a new point layer based on the mid point of a line layer (and keep all the feature attributes in the table). For example, one line feature becomes one point, located on ...
6
votes
4answers
5k views

Querying points inside and outside of polygons?

In PostGIS I have two tables: Table that contains polygons: table a.provinces gid | geom | name | ------------------------------ 1 | 010604 ... | Champagne | Table that contains ...
6
votes
3answers
306 views

Insert n points equally distributed into many polygons

I know the "Random Points inside Polygons" tool in QGIS. It generates the below output. What I want to achieve however are 8 equally distributed points for each of the polygons. I thought of dividing ...
6
votes
1answer
864 views

Interpolation: irregular shape, merging DEM's

My problem is quite complex, but I hope that solution may be simple or at least possible. I do have .img DEM 0.5x0.5m. DEM consists of river bed, river valley and adjacent areas (it is strip of 5km ...
6
votes
1answer
23k 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.
5
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2answers
8k views

How to convert a line to points?

I'm working with QGIS and I want to convert a line into many points, does someone know how?
5
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3answers
1k views

Does anyone know a function to determine if a Point lies on a polyline?

ArcEngine 10 .Net 4 c# I'm currently allowing user to select a point on a polyline and creating a point on the line. I am using snapping tool. I just want to make sure that when the user clicks on ...
5
votes
1answer
1k views

Find the closest line vertex from the linestring using PostGIS

How to find the closest line vertex from a linestring? ST_ClosestPoint will give a point which is not from the linestring.
5
votes
1answer
1k views

R - multicore approach to extract raster values using spatial points

It might look like this question is duplicated, but I'm asking about data extraction by points, rather than by polygons, and I couldn't find hints about point extraction. Therefore, please bare with ...
4
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3answers
1k views

Extract highest point in raster and convert to point vector

I have a raster DEM and I want to extract from it the highest point found in every polygon of a polygon shapefile. The result that I would like to obtain would be a point shapefile with 2 collumns: ...
4
votes
1answer
182 views

PostGIS point distance from polygon not 0 when on edge

I have a pretty simple problem: SELECT * FROM ST_Distance(ST_GeographyFromText('POLYGON((70 -40,70 -39,71 -39,71 -40,70 -40))'), ST_GeographyFromText('POINT(70.48 -39)'), False) returns 118....
4
votes
1answer
540 views

How to interpolate missing data from neighbours in PostGIS?

I have a dataset with point data within a given country. Let's say my dataset looks somewhat like this: tree_id | species | age | geom ------------------------------ 0 | Ash | null| ... ...
4
votes
1answer
2k views

Calculating attribute for network distance between multiple points in ArcGIS Desktop?

There is a road network and two point feature classes. For one feature class, I need to calculate a field to hold road (not Euclidean!) distance from every point to a certain point in the other ...
4
votes
2answers
8k views

PostGIS convert geography(Point,4326) to GPS

I got a database with a column of type geography(Point,4326), the data contained looks like 0101000020E610000092E057F66EF73140930035B56CBD4840. How can I convert it to GPS coordinates?
4
votes
4answers
3k views

How to determine a point lays within a polyline in arc engine?

I recently asked a similiar question on this, however I needed to know if there is a way to solve this if I only have a IPolyline Feature, and not the whole layer. I want to know if I can determine ...
4
votes
3answers
3k views

Comparing two point shapefiles that contain lat/longs and compute distance using ArcGIS Desktop?

I have 2 sets of point shapefiles in ArcGIS Desktop (group A and B), each set has around 1000 entries that contain lat/long. What I want to do is compare Group A against Group B and figure out for ...
4
votes
1answer
9k views

Creating Isolines from point Data

I'm quite new with ArcGis 10 so I’m having difficulties with something that may be simple to some. Anyway I have a list of bores that I’ve plotted using coordinates. Now I need to draw a single ...
4
votes
3answers
5k views

Counting number of points within a grid

I'm trying to count how many floods occur within a given grid cell in ArcMap and I can't figure it out. I've been reading some other posts on here but I haven't been able to find an answer. I have ...
4
votes
2answers
2k views

Calculating the distance between points and multiple lines?

I have a point shapefile of about 100 points and a polyline shapefile of about 200 lines and I am interested in finding the distance between every point and each individual polyline. My polyline ...
4
votes
2answers
2k views

Calculate distance of points - SpatialPoints object - along a path - SpatialLines object - using R

I have a SpatialPoints object and a SpatialLines object. I want to calculate all the distances from the start point (first coordinate of the SpatialLines object) to every point in the SpatialPoints ...
4
votes
1answer
2k views

Finding projection of point to line?

I have a segment defined by 2 LatLon points(A and B) and a third LatLon point (C). I need an alghorithm, formulae, or some code to find the projection point of C on the segment AB (call this point D) ...
4
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0answers
106 views

Action: Move pointfeature to other layer - Point becomes Multipoint

I'm trying to write an action that moves a pointfeature from one layer to another. It works fine until i try to save the layer with the new feature on. He says he can't save a MULTIPOINT to a point-...
3
votes
1answer
520 views

Getting value of pixel and its 8 surrounding pixels from points using QGIS

I have a point Shapefile layer and a land cover raster layer. For each point, I want to get the value (land cover) of the pixel it falls into and also of the 8 surrounding pixel. Is there a tool in ...
3
votes
1answer
84 views

Determine if Point is in feature class attribute table

I'm working with ArcObjects, C# and ArcMap. I have an attribute table that has several rows of data including a "shape" field that holds a point geometry. I also have a random point. How can I iterate ...
3
votes
2answers
155 views

QGIS Assign point data to a line layer considering line direction

I have a line layer representing a river bank. The river bank is divided in numerous separate line features representing zones, each separate line has many vertices. The lines have a set direction. I ...
3
votes
1answer
2k views

Problem creating point shapefiles programmatically using python in QGIS 2.2

I am trying to create a point shapefile in the memory buffer (for a temporary label) and then zoom to the extents on this buffer. The working (in version 2.1) test code for this is: def ...
3
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0answers
111 views

Grouping neighbor points based on field sum in QGIS

I have about 14,000 points. These points have a specific field "time", an integer value, mainly between 1, 2 or 3. I would like to split these 14,000 points into groups based on the "time" field ...
3
votes
2answers
3k views

Merge single points to multi point geometry

Is it possible to transform a point shapefile in single part geometry to a shapefile with multi-point geometry based on an attribute. e.g. in the file are 50.000 records in 700 categories, now I want ...
2
votes
1answer
102 views

Delete points on one side of a line in QGIS

I have a bunch of points and line that represents a boarderline as shown below: I want to delete all the points one the right side of the line, and letting the points in the left side stay. I dont ...
2
votes
2answers
536 views

Points to path segments

I have a point shape (ID, value) which I have converted to a path (points to path). Is it possible to get the lines between each point? The picture below shows what I mean. The colored path is what I ...
2
votes
0answers
461 views

R coordinates on line nearest to point - multiple points

In R, I have a collection of points (~15,000) within a polygon. For every point, I want to calculate the location on the polygon boundary nearest to the point's location. I'm not bothered about the ...
2
votes
1answer
6k views

generate random world point geometries

I have a world map. I need random point geometry. So, how can I randomly generate point coordinates? Any programming language. Also, I am using SRID 4326. Any programming language.
2
votes
3answers
611 views

Nearest distance from point to pixel in QGIS?

I have 1) a point layer and 2) a binary raster file (1 and 0). I need to estimate the Euclidean distance from each point to the nearest "1" pixel. I know there is a tool in ArcGIS but I only have ...
2
votes
2answers
669 views

How to convert Point coordinates into CSV format?

The GDAL documentation describes how to convert a ShapeFile into CSV data. The layer create options (-lco parameter) allows to prepend the coordinates of Point features to the actual attributes values....
2
votes
0answers
68 views

Generate ID for the grid of points from top-left corner down [duplicate]

I have a grid of points extracted from a raster. I need to give them a new ID value to be able to join values from it to another grid in rotated system of coordinates.The automatically generated ID ...