Tagged Questions

2
votes
0answers
55 views

Point file to raster

I have a point file of trees in my study area, which includes the attributes of each tree. Each tree also has a crown radius associated with it. I need to summarize the attributes of these points ...
3
votes
1answer
342 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 ...
2
votes
1answer
50 views

How could I assign point values to a raster stream segment?

I need to assign a point value in raster format to a raster stream segment, which contains the point. See bellow: The expected result is a segment, whose value is the point value. How could I?
7
votes
3answers
441 views

Creating raster or vector raster from DEM point file?

i have a point shape of 75.000 elevation points in a regular 5 m grid. We now want to create a polygon grid with the elevation points as "centroids". Unfortunately, all attempts to do so fail: I ...
4
votes
4answers
333 views

How to sample raster datasets at ALL points?

I know it is possible to use tools like ArcGis's 'extract sample' tool to extract values at a given number of points. I would like to sample every pixel in a raster, and drill down through all other ...
3
votes
2answers
322 views

How to extract cell values from a raster file with Idrisi Taiga?

I need to convert raster cells into points. I use Idrisi and I need to generate a table containing xy (coordinates) and z (cell value).
3
votes
1answer
935 views

Calculating distance to points in QGIS

Is there a way of calculating the distance to the nearest points in QGIS? In ArcGIS there is a function called Euclidean Distance, which can take an input vector or raster, and generate a raster of ...
5
votes
3answers
902 views

Easily find centre point of a raster in ArcMap 10 document?

If I have, say, a rectangular and georeferenced raster file loaded in an ArcMap 10 document (.tiff w/ associated tfw), how do I easily find its centre point and store that point in a points vector ...
7
votes
2answers
707 views

PostGIS raster value of a lat/lon point

I have a tiff raster in my PostGIS 2.0 database. I want to get the value of the raster at a specified lat/lon point. I have: postgresql-9.1 postgis-2.0-svn with raster support a raster imported ...
6
votes
3answers
713 views

Converting point data into a weighted raster

I am completely re-writing my question as i think it was quite confusing before: I have a number of different points, each point has a -z value. I need to create some sort of raster or a series of ...
1
vote
3answers
374 views

Point to Raster Issues

I am having some trouble with something fairly simple.. I am creating a 3D subsoil model for display in arcscene - i can get it displayed nicely as points but in order for the model to be easier to ...
6
votes
7answers
2k views

Extract raster values at points

How can I extract values from a raster by points. I prefer not in Arcgis. I prefer in Qgis or Mapwindow or other open source gis.