Use the `raster` tag for questions about raster datasets. A "grid" is a regular partition of a spatial domain into congruent nonoverlapping pieces or a set of lines forming a grid-like pattern (aka "graticule").

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0answers
65 views

How to rotate u and v components of wind in rotated gribs?

I have a grib message of a rotated hirlam product. The gribmessage states, that the u and v component contained are relative to the rotated grid. How can I unrotate them?
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1answer
38 views

Why are color settings are not saved when exporting to a new file?

I extracted with QGIS a municipality from a state map, then divided it with a grid. I don't want the borders of the grid features to be seen so I changed the color of the map and the color of the ...
0
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1answer
157 views

Polygon grid shape file for landmass

I am interested in generating a polygon grid shape file for the landmass of the world. What I have presently is two tables in postgreSQL. Table 1: Coastal area shapefile ...
2
votes
1answer
51 views

Divide map into features with invisible divisor lines

I'm working with QGIS 1.8.0. Is there a way to divide a map with a grid but make the divisor lines invisible? I have a shapefile as the one in the left and I want it to see as the one in the right but ...
0
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1answer
64 views

How to know the real size of grid? [duplicate]

Im working with QGIS. When dividing a map with a grid I set in the paramters X=0.1 and Y=0.1. Could someone please explain what does that mean? I mean would the map be divided into 100mx100m squares? ...
3
votes
1answer
80 views

How to tell the size of grid cells created by the vector grid tool?

Im working with qgis 1.8.0 and Im making a vector grid on a map. Does someone know how big are the squares if the grid settings look like in the picture? Thanks for your time!
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0answers
46 views

Borderlines of states subdividing my GRID

![enter image description here][2]I just merged a map of a country with its states, so I went from having 1 feature (the whole country) to 32 features. Is there any way to have the borders of the ...
2
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0answers
39 views

simple raster format to use in Web applications?

I'm building a Web application in which users create and edit very coarse raster data. They're assigning values to cells in a georeferenced grid. Right now I'm storing the values in a multidimensional ...
1
vote
1answer
140 views

How can I bring in grid files from Geographix into ArcGIS?

I have a set of grids of subsurface horizons, created from contours, that I have created in Geographix and am having trouble brining them into ArcGIS. Currently when I try to export the grid ...
1
vote
2answers
107 views

AML routines and python

I´m trying to use some AML files in ArcMap 10, but I have noticed that this option is not available for this version. Does anyone know or tried to "translate" the aml sequences to another language ...
0
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1answer
166 views

Measure length within a grid

I have a grid and some lines within a grid and I was wondering how to measure the length of the lines inside the grid. I can use the measure tool for a straight line, however in the future I will not ...
1
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0answers
13 views

How to assign a grid value to points? [duplicate]

I'm sure there is an easy way to do what I am trying to do but I cant seem figure it out. All that i would like to do it create a grid (say 10mx10m) with unique values (i.e. grid 1,2,3,4) and then ...
1
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3answers
979 views

how to create grid to divide large map into smaller sections

This seems like it should be easy but I just can't find anything online that tells me how to do it. I have a map of small remnants of forest along creeks for an entire county in California. I need ...
0
votes
1answer
142 views

How can I label each gridsquare in an MGRS grid individually?

I want to be able to generate an MGRS grid of arbitrary resolution (say, 1km or 100m) and have each grid square individually labeled with its full MGRS coordinate. This was easy enough to do with the ...
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votes
1answer
332 views

how to run an aml in python

I am trying to run a aml in a python program I am writing and haven't been having much luck figuring out the correct way to run the aml. The aml requires workstation to be in grid mode. Any tips? I am ...
3
votes
1answer
604 views

Why does QGIS hang when I try to create a vector grid?

I am working in open layers plugin.i need to project the satellite data with respect to vector data shape file i am having .for that Andre Joost suggested to create vector grid with vector data ...
1
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1answer
1k views

Overlay lat/long graticules on projected map QGIS

I am using an equal areas projection of North America and would like to overlay a lat/long grid. I can do this in the print composer, but only for the coordinates. Can QGIS do a distorted grid for ...
1
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0answers
102 views

Problem using grid with a vector layer

I need to establish a model of maritime pollution and I try to use the grid option to work on ocean sectors. I tried to use my grid on a vector file, .shp, with points. Each point is a maritime ...
2
votes
3answers
535 views

Looking for a fine U.S. Latitude and Longitude grid (0.25, 0.5 degree)

There is a global latitude and longitude grid data available at 1 degree resolution and higher (http://www.arcgis.com/home/item.html?id=f11bcdc5d484400fa926dcce68de3df7). Is anyone aware of a finer ...
1
vote
1answer
673 views

How to draw grid cells in QGIS?

I have one ASCII text file with eight columns. The first four provide the x-coordinates (e.g. longitude) of the four corners of a grid cell, while the last four provide the y-coordinates (e.g. ...
0
votes
2answers
659 views

How can I generate a fishnet grid and a matrix of percentage of overlapping in R?

I'm trying use R for create a fishnet grid like in arcGIS with many cells of same size. In the arcGIS 9.3 we have the option of create a polygon with many small square polygons (eg. 1 x 1 degree of ...
0
votes
3answers
688 views

How to generate a shapefile with UTM Grid precision level 100 m [duplicate]

Does anybody know, if I can download from somewhere UTM Grid for zones 33 to 35 and U belt (for Poland) in shpfile or different format I can convert to shp. I need precision level 100 m. Is it ...
2
votes
1answer
133 views

filter / generalize elevation points on the basis of some conditions

I wanted to generalize many elevation points in a rectangular area (about 700 square km). I need to take about 3 points for square km. These points must satisfy some conditions: One of these ...
3
votes
1answer
268 views

Find which grid cells contain a point

I have a dataframe with x,y coordinates. I've sampled 10 x,y coordinates from my dataframe: y <-c(24.637032,21.569813,21.687,19.677183,24.72438,21.433136,24.637032,22.21065,21.443762,25.273882) x ...
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1answer
260 views

How to divide a certain country on a map into grids?

I want to divide a certain country into grids 1,2,3,..., which are divided equally - in other words, have the same width and length. Then, I want to know into which grid a point coordinate will fall ...
5
votes
1answer
257 views

Help with grid creation in QGIS

I have 235 raster tile 20km x 20km. I need to create a grid to overlay across them...ie the grid itself will be 20km x 20km, with the lines of the grid on the boundaries of the tiles. I am assuming ...
2
votes
1answer
194 views

How to flip X and Y coordinates of a grid by GDAL

I have a grid, which has flipped X and Y coordinates (X is represented by Y values and Y is represented by X values). This results in grid being positioned in completely wrong place. How can I flip ...
10
votes
2answers
2k views

Aggregating points to grid using R

I have a question with regard to spatial aggregation in R. What I am trying to do is aggregate a point dataset to a grid. I am unsure however how to do this as I have little experience with this sort ...
2
votes
0answers
128 views

Plot the Shortest Paths in a Grid without any clash at a point of time

The efficient algorithm needs to be done and proved for the best solution for the given problem: User inputs: (#) Size of the NxN Grid. (N); (#) No. of Paths: Z; (#) Source and Destination ...
5
votes
1answer
464 views

Converting polygon values to a vector grid using PostGIS

What is the best way of converting a value from irregularly shaped poylgons to a polygon grid using PostGIS? I have a set of polygons that look like this: and I would like to overlay a grid on ...
4
votes
1answer
132 views

How do I split a vector layer into separate grid layers?

I need to split a vector layer into 1km x 1km squares so I can carry out some calculations for these individual areas. Is there a feature to do this?
2
votes
2answers
329 views

gridlines are on top of some text boxes but below others, how do I make it so that the text boxes are above the gridlines in all cases

I am working with a map and instead of using the labels feature I chose to use text boxes because the labels were not where I wanted them to be. I set up all the text boxes and then added gridlines ...
6
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1answer
2k views

Grid and Graticule in QGIS Print Composer

Is there any other option to display DMS grid and graticule in QGIS Print Composer, since there is no plugins available yet?
5
votes
1answer
133 views

How to convert PostGis Table (Grid data) to Continuous field using Qgis?

I'd like to transform my Gridded Layer (generated form a PostGIS table of points) to a continuous and colored layer. How could I do this with Qgis or any other program? Many thanks and best regards, ...
1
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2answers
461 views

Arcpy (10.0) and centroids/points shapefile

I'm trying to create a point shapefile from a grid index polygon shapefile I created using arcpy. I know this is simple, but could anyone give a few pointers out there. Here is what I've done now: but ...
2
votes
1answer
162 views

How extract data from a SNODAS file

I'm trying to extract data from a raster file from "Snow Data Assimilation System (SNODAS)" and convert it to a MMQGIS (plugin) grid layer (Hexagon) with QGIS. This raster file stores the snow depth ...
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votes
1answer
579 views

Exporting Grid from R to use it in ArcGIS

i want to export a grid from R into format readable by ArcGIS. how can i do so? jones
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2answers
91 views

Distribute gridded data to corresponding subbasin boundaries

I have one ArcGIS shapefile of my river basin consisting of many subbasin. Another shapefile showing the location of gridded points over the whole basin (Its latitude and longitude are used as file ...
5
votes
1answer
538 views

How to emulate a specific vector grid in QGIS?

I would like to analyze data included in a pdf file. The file contains information on characteristics of 16km grid cells for a specific study area. The file also includes a map displaying the grid. I ...
0
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0answers
99 views

How do I determine programmatically what values to add to the proj4js constructor for a CRS or SRS such that I can iteratively render proper overlays

I think this is primarily a GIS based question as far as for example: var crs = L.CRS.proj4js('EPSG:2154', '+proj=lcc +lat_1=49 +lat_2=44 +lat_0=46.5 +lon_0=3 +x_0=700000 ...
2
votes
1answer
498 views

How to export vector features to grid using proxy and WFS protocol?

I am trying to export vector features (current view) as a grid, something like: http://workshops.opengeo.org/geoext/wfs/grid.html so far layer features are not being retrieved.. I got empty grid in ...
6
votes
3answers
951 views

Find a proper path between two nodes in a grid

This question is about finding a proper path (route) between two nodes (P,Q) in a grid (i.e., graph, network, ...). In our concept, we define a path proper (nice) if it is the most similar* to the ...
3
votes
1answer
212 views

Polyline “breakage” calculation in MapInfo?

I am a novice MapInfo user, with a basic to moderate knowledge of queries and SQL. My work entails doing risk assessments for shipping traffic based on AIS-tracks (radio-based vessel information ...
3
votes
1answer
1k views

How can I add a grid (from projection MTM8) on my layers

I need to add a grid on a map I created with my own layers and GPS data. How can i do this? I know how to do it in Arcgis, but not in QuantumGIS. Can you help me?
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0answers
270 views

In ArcGis 10, spatial join of a hot street value to a fishnet cell is counting multiple values for same street segment

So, I am working on a fishnet, so that we can attribute multiple values to points within different cells (i.e., ranking light poles as optimum for traffic cameras based on the number of speeding ...
2
votes
1answer
1k views

Convert X Y Pixels to Easting Northing

Hopefully someone can help. I'm trying to find out what the formula would be to convert the X, Y of an image to the Easting and Northing coordinates. I've downloaded some of the raster maps from OS ...
4
votes
1answer
748 views

How to create a 500m Regular Grid for KML input area?

I am hoping to create a point grid over the city of Edmonton. My workflow is: Import a KML of Edmonton neighborhoods from here Save the layer as a SHP Delete the layer and load the SHP Define the ...
0
votes
2answers
277 views

QGIS regular points around each polygon in a layer (vs ALL polygons)

I have a number of buffered points (some where polygons intersect & are dissolved. I'd like to create regular spaced points grid around EACH polygon -- not ALL polygons. When I do Vector -> ...
6
votes
2answers
4k views

Create a polygon layer from point data

I'm currently using QGIS 1.8.0 I would like to create a polygon layer from a point dataset, where the size of the polygons relates to the resolution of the grid reference. The ultimate aim would be ...
3
votes
1answer
137 views

Method to compute and visualize the closest set of facilities from OSM data

I want to use OSM to extract a set of facilities e.g. school, park, hospital inside a given region. from that, transform the area in grid and for each cell in a grid compute its score mixing the ...