Refers primarily to graticules and questions about drawing or constructing them. Use the `raster` tag for questions about grid-based datasets.

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8
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1answer
2k views

How to convert point data into a gridded dataframe for histogram analysis?

I am very new at using GIS data and only modestly experienced with R. I've been reading about how to analyze spatial data using the spatial-analyst.net PDF book, so I'm not completely lost, but I ...
8
votes
3answers
2k views

Creating regularly spaced, defined # of points within polygon in QGIS

I used the research tool "Regular Points" to produce a certain number of points within a polygon, but it forms a rectangular grid of points rather than only within the shape of the polygon. Since I ...
7
votes
1answer
1k views

Coordinate grid display on a rotated map

I have a series of maps that require me to rotate my data frame within my layout screen (north "rarely" points up in these maps). I ONLY want to show east coordinates on the top/bottom and ONLY north ...
6
votes
6answers
739 views

How can I convert a DEM into areas of “flatness”, with an arbitrary fill/cut to area ratio?

I want to find areas of relative "flatness" in a DEM. How can I find flat areas? I want to find a neighbourhood of contiguous cells that have an elevation variance that is within a certain ...
6
votes
1answer
1k views

ArcGIS 10: Adjust custom grid intervals based on map scale?

I am preparing a pmf which includes a custom grid overlay. To clarify: a custom grid overlay is marginalia, not a feature class with geometry (so a scale dependecy inside a layer won't work). The ...
5
votes
2answers
449 views

Optimum grid/pixel size for interpolating rainfall and temperature

I have a set monthly rainfall and temperature data within an approximately 100 x 100 km study area. The sampling points are unevenly distributed within the study area. Based on a paper by Janis et. ...
5
votes
3answers
392 views

In what data format should I export a (lat,long,alt) or (x,y,z) grid to be compatible with the largest number of GIS software?

I am new to GIS and developing an application that generates a 3D grid with (latitude, longitude, elevation) or (x, y, z) metric triplets, and I would like to add an exporting feature that ensures ...
4
votes
1answer
856 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 ...
4
votes
1answer
351 views

Sub-dividing a polygon into smaller polygons

In OpenStreetMap data, some large areas are tagged with a residential=yes tag. Actually within this large polygon there are multiple smaller (rectangular) houses (which are actually not drawn as yet). ...
3
votes
2answers
2k views

How to convert GRIB-1 to GRIB-2?

I need to get data for my database from some GRIB files (binary), I downloaded wgrib2, which can export GRIB-2 files to .csv and csv is very suitable for me, but some GRIB files are GRIB-1, so I used ...
3
votes
2answers
1k views

Conversion of GRIB and NetCDF to my database

. I have downloaded "High Resolution Initial Conditions" climate forecast data for one day, it was in extension .tar.gz so I extracted it in my local directory and I get the files like in the ...
3
votes
2answers
1k views

From point to Grid of polygones or polylines

Is it possible to reconstruct a grid of polygones or polylines from the centroids? I am looking for a arcGIS tool or script that will allow me to reconstruct a grid of polygons or polylines from ...
3
votes
1answer
261 views

Dividing a geographic region

I have a certain geographic region defined by the bottom left and top right coordinates. How can I divide this region into areas of 20x20km. I mean in practial the shape of the earth is not flat it's ...
3
votes
2answers
438 views

TIFF, Grid, FGDB Grid, etc. - what performs better in ArcScene animation?

I am creating a flyover animation in ArcScene and I would like my surface raster to be rendered in full resolution (an exported function raster dataset - a blend of shaded relief and high resolution ...
3
votes
1answer
77 views

How to modify height model values outside of road network

I have a height model of a quite big area saved in Esri ASCII grid files and a road network of this same area in a shapefile. I'd like to convert every height model value outside the road network to ...
3
votes
1answer
141 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 ...
3
votes
0answers
117 views

How to view Esri GRID format file in wxpython file browse window? [closed]

I'm trying to browse for all kinds of vector and raster data using a filebrowsebutton. The problem is I don't know how to let the browse window see the Esri GRID files (which contains a folder and a ...
2
votes
1answer
1k views

How to create a grid constrained within a polygon in QGIS?

In QGIS I have created an irregularly shaped polygon. I can create a grid based on the maximum extents of the polygon via Vector>Research Tools>Vector Grid. However, what if I need the grid to ...
2
votes
1answer
188 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 ...
2
votes
2answers
2k views

Converting xyz batch to ESRI grid format using XYZ2GRID 2.1 - batch problems

I am trying to use Min-Lang Huang's XYZ2GRID2.1-Batch program downloaded from ArcScripts and I keep getting the error C:\users\public...........xyz Error-Object required Does anyone know what the ...
2
votes
1answer
557 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 ...
1
vote
1answer
755 views

How to convert a polygon to a grid of polygons using QGIS?

For example, the city of Rotterdam represented as a hexagonal grid.
1
vote
1answer
1k views

Generating Map Tiles for MGRS Grid Graticule

I'm possibly a bit out of my league here, but ready to get my hands dirty. I want to generate map tiles for a MGRS grid graticule similar to http://tiles.mapbox.com/mapbox/map/afghanistan-mgrs. I ...
1
vote
0answers
98 views

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

I have a grib message of a rotated hirlam product. The grib message states, that the u and v component contained are relative to the rotated grid. How can I unrotate them?
1
vote
0answers
123 views

Arcobjects - Properties Grid

Does anybody know a way, in VBA, to change the grid interval? For example: if my layout´s scale is 1:2000, my grid will have 200 meters interval and my layout´s scale is 1:5000, my grid will have 500 ...
0
votes
1answer
371 views

Arcmap 10 corner label measured grid

I am using the corner label feature in Arcmap 10. This allows you to set the "Numer of principal digits" and the "Number of base digits". What do these properties refer to?
0
votes
0answers
937 views

Lat/long grid in QGIS using WGS84 projected layers [duplicate]

I'm using QGIS to project some shapes that are in WGS84 coordinate system. I want to add a grid to the map in the map composer but when I try to do it the degrees don't show up. I have tried to do ...
0
votes
1answer
124 views

Why are grid and scalebar measures 1mm too long in a 1:10000 print?

I used qgis 1.8 to compose a map from the WMS-service of the Belgian NGI. I added a scalebar and grid to it. When I measure it by hand, the distance between the longitudelines is 101mm instead of ...
0
votes
0answers
166 views

SAGA grid VRT, file how to apply a LUT?

I've created a heap of saga grid files for some hydro survey work. I'm looking at a way to read these into a mapguide raster/grid layer, I'm able to load up the grids using a vrt file, I can't figure ...
-1
votes
1answer
384 views

how to make grid cells by point data

I have a csv data. the X, and Y columns show bottom left corner of each grid. It is supposed to show as grid square, but it shows points. what is the problem? and is there any way I can make cell ...