Raster is a data format consisting of regular grids of values, usually stored in an image-like format.

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Why does heatmap size vary with number of points

I am making three heatmaps based on points over the same area and don’t understand why the number of rows and columns would vary depending on the number of features. The first feature set has 398 ...
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16 views

Raster images at edge of data frame not displaying. How can I prevent then from disapearing?

I have a series of satellite images and as I pan or zoom, the images near the edges of the data frame the stop being displayed leaving small areas with no imagery. It is seems to occur when only ...
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41 views

Zonal statistics won't work after re-projecting vector layer

I have qgis 2.0. I want to analyze raster information within a buffer of 30 miles around a vector layer of cities across the world. However, both the raster and the vector are in WGS84. I have no ...
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58 views

Dates are off when opening netcdf file in R

I have a netcdf file with the time dimension that goes from 12/2007 until 12/2010 with monthly time steps. I can see the correct dates in both arcgis and panoply. Panoply tells me this file is a ...
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16 views

How to obtain stream segments from complemented image(raster data)?

I have raster data in tiff format, i want to extract stream segments from the complement of original raster data. I am able to extract stream segments from original raster data, but not able to ...
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60 views

Update a NetCDF file using GDAL

I have to edit a NetCDF file using GDAL in C++ code. When I try to update a subset I have this error message: ERROR 6: The NETCDF driver does not support update access to existing datasets. How can ...
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24 views

buffer of clusters in a sparse matrix

I work with MATLAB. I have a sparse matrix where I identified different clusters. The value within each cluster is equal, while each cluster has its own unique value. I have 0s as background (outside ...
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89 views

Choose what zoomlevel to read from for mbtiles file in GDAL

GDAL is supposed to read MBTiles files and to do so, it selects the highest zoomlevel available. However, is there a way to choose another zoomlevel? i.e. override the default and go for a lower one? ...
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62 views

How to split a raster into multiple rasters using QGIS?

I would like to know how to split a raster into multiple rasters in a single operation using QGIS. Although I can clip the raster image, it would be better to split it using a single operation. I am ...
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77 views

recording pixel value with Python script in ArcGIS 10.x

A scripting newbie question... I'd like to write a Python script for ArcGIS 10.x that would record the pixel value for all pixels in a raster. Furthermore, I'd like to only record a given value once ...
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37 views

recording pixel value with Python script in ArcGIS 10.x

A scripting newbie question... I'd like to write a Python script for ArcGIS 10.x that would record the pixel value for all pixels in a raster. Furthermore, I'd like to only record a given value once ...
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146 views

gdal python set projection of a raster - does not work

Gdal 1.9.2, ECW driver: ECW/ERDAS Compressed Wavelets (SDK 3.x) I am having problems with the script that supposed to set projection of the ECW to EPSG:27700, i.e. the British_National_Grid. Please ...
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90 views

Geoserver raster (in geotiff format) becomes black when grouped by other layers in vector format?

Good day, I am a newbie in field of GIS systems. Currently I have an issue when grouping layers, raster and vector. I would like to use satellite image in geotiff format as a base layer. It works ...
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18 views

How to iterate the area of uniqueValue in raster?

Here is a figure shows the result of the classify after using "IMultivariateOp.MLClassify",but how can I iterate them? Can I iterate them directory instead of using IRasterWorkspace or ...
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82 views

Strange black pixel on edge when generating with gdaldem -hillshade

I'm getting a strange result when I'm generating an hillshade with the gdaldem hillshade command. Here is my command (see the compute_edges parameter): ...
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46 views

How can I add/define a legend for RGB images in QGIS?

I have a RGB image in QGIS that is the product of some raster analysis (e.g. QGIS's relief operation, results from sound/traffic models) to which I want to add a legend. I'd like to denote several RGB ...
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307 views

ModelBuilder: iterate raster output as input for raster calculator?

I remove values (above 249 and below 49) from raster files (called Name in the example) with the raster calculator. I do this by passing the following condition to the raster calculator: Con("%Name%" ...
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43 views

Geoserver WMS request raster clipped with field boundary

I have recently set up GeoServer instance and uploaded raster data and a set of field boundaries. I would like to be able to select a field boundary and have the server return the portion of the ...
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121 views

converting vectors to raster (burning streams)

I converted my stream vector to a raster file (using polyline to raster conversion tool). I anticipated that I would get a No Data row in the raster file attribute table, so that I could use a ...
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117 views

Why does Make NetCDF Raster Layer tool give Error 000276?

I am trying to view NetCDF files created into WRF into ArcMap 10.2. I used the 'Make NetCDF Raster Layer' Tool as described on the user-guide however, I keep getting the same error: 000276. Would any ...
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70 views

change unit while outputting raster to ascii

I am having a problem with outputting ascii from raster file. I've reprojected and set map unit to meter in ArcMap. I've also set the output environment-ish parameters like output projection, x-y ...
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20 views

Abnormal DEM values after fill operation

With arcmap 10.1. after filling the DEM the value range is -70 to 1078, but it should be between 225 to 1200. Can anyone suggest me a methodology or the necessary steps in arcgis 10.1 to mend my ...
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67 views

GRASS v.to.rast.attr returning null values

I am having a problem converting vectors to rasters in QGIS. As there is no tool where you can directly set the pixel size (instead of the height and width of the new file) in QGIS 1.8 (the version I ...
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28 views

Warping Rasters in QGIS

There seems to be a bug warping rasters in the new QGIS version 2.0 When you have to option of target and Source SRS, the Coordinate reference system does not get automatically writen into the box ...
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26 views

calculate proportion of polygon greater then 40 degrees in grid cell QGIS

I would like to calculate the proportion of greater then 40 degree slope within my polygon grid cells. I have a Slope Raster layer for my given area and have a polygon that overlays this raster ...
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20 views

Creating clumps of cells in a raster from seeds of 1 cell (in ArcGIS)

I need a process similar to that described in JPD's question: Creating randomly shaped clumps of cells in a raster from seeds of 1 cell/pixel? I have a raster with semi-randomly dispersed "seed" cells ...
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86 views

QGIS 2.0 change the raster band from python command

Does anyone know how to change the band of a multiband raster from the python command line in QGIS2.0? It used to be done with something like rLayer.setGrayBandName(1) in 1.8, but this is no longer a ...
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149 views

How to convert Raster to points in MapInfo?

I wanted to convert Raster data to point data in MapInfo.Does there any tool to convert? can anyone help me?
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61 views

Interpolation Technique

We have following solar metro logy parameter through satellite data with resolution of 100 Km^2 (10Kmx10Km) Insolation on horizontal surface Diffuse radiation on horizontal surface ...
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93 views

Methods to calculate Viewshed analysis

Does anyone know an algorithm to calculate Viewshed analysis? I calculated them in ArcGIS, MapInfo and SAGA GIS. I wish to calculate Viewshed analysis using algorithm or methods which I can use in ...
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34 views

Can´t display two files at the same time

for some reason when I open a raster FIRST and then a shp, I can only see the raster. Then if I open the shp FIRST, and then the raster, I can only see the shp! Is there a bug on QGIS? Or have I ...
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57 views

Updating a raster dataset stored in SDE, without schema changes

The Short(ish) Version: I have some rasters, that are generated nightly, that I need to insert into an SDE instance (10.0), sitting on top of an Oracle database (11.1.0.7). I have many users who ...
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62 views

Creating a mosaic dataset from pre-existing mosaic datasets

I wanted to see if anyone has tried this, or knows of any issues that may arise from performing such a procedure: I have about 20 mosaic datasets already created in separate file geodatabases. I ...
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31 views

Create a mask for a 3 Band Raster Image with surrounding white areas

How do I create a mask in order to clip a 3 band raster image so that the surrounding white area does not display. My thinking is to use Raster Calculator to create the mask or cut all three bands on ...
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42 views

Intersect two rasters with similar scale in PostGIS

I'm working on a project in which we have a ~100x100km grid with ~1x1km cell sizes to which we are trying to aggregate other data, including point, polygon, and raster data. This grid is a collection ...
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62 views

Using Raster Data in a Vector Layer's table in QGIS 2.01

I have a vector layer containing point data representing floor levels. The attribute table contains: Easting Northing Floor Level I also have several water surface levels representing the ...
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120 views

Problem with merging 15 DEM files in ArcGIS

I have 15 DEM files downloaded from USGS website. The pixel depth of each file is 32 bit floating, generic with format FLT. I'm then using data Management Tools > Raster dataset > Mosaics to new ...
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65 views

How to remove Raster from Raster Dataset programmatically?

I have Raster (it is 6 adf files). This raster was added to Raster Dataset in sde database. Geoprocessor geoProcessor = new Geoprocessor(); Mosaic mosaic = new Mosaic(); ...
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222 views

Tabulate area - Spatial Analyse

I am trying to calculate the amount (sqm) of land cover types (forest, water ect.) in 1045 buffer zones, all the same size (500m in diameter).. The buffer zones are polygons and the land cover is a ...
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54 views

Is anyone else working on PostGIS rasters for Ruby?

This is more of an answer looking for a question, really. If you're writing Ruby (and especially ActiveRecord) code and want to use those tasty pixels from PostGIS rasters, you've probably had to deal ...
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136 views

Trying to build pyramids for large raster

I finally was able to make a slope with a rather large 5m DEM. But now I it usually wont finish drawing. When ArcMap asks to 'build pyramids' it always freezes sometimes instantly after accepting ...
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61 views

Using arcpy.GetRasterProperties_management gives strange results

I have a loop which goes through folders and do some raster operations. Inside this loop I checked for a raster properties using arcpy.GetRasterProperties_management with NODATA parameter. And then ...
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75 views

Compare cell value of a row

How can I compare the cell value of row(n) with cell value of row (n+1){where n = 1, 2, ...} import arcpy arcpy.env.workspace = "C:\RG\Kings County\Test.gdb" inFC = arcpy.GetParameterAsText(0) inFC ...
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144 views

QGIS 2.0 cannot open TIFF

I've just installed QGIS 2.0 on my Windows 7 computer. I'm trying to open a raster and the system reports this message: Cannot open TIFF file due to missing codec. How can I solve it? Thanks in ...
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103 views

How to create a raster dataset from a known decimal extent?

I have an input raster pInputRaster. I want to create a new raster dataset called pOutputRasterDS that is the same width, height and cellsize as my input raster dataset (I'm not worried about ...
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37 views

How to select raster layers for averaging based on values in another layer?

I wonder if anyone have some ideas about how to solve this geoprocessing situation: 1: I have a raster layer called mixlyr_apr (representing depth values) 2: I have a series of raster layers called: ...
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109 views

QGIS GRASS Rasteranalysis (r.los)

I want to determine the area around a wind turbine from wich the object is visible. I want to use r.los in GRASS i get this error: (German) r.los input=dgm@sichtbarkeit coordinate=534228,5406743 ...
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160 views

QGis: merge point and line vector themes to create single raster

I have two vector shapefiles with different geometries: point theme with depth attributes and line theme with contour of water body (zero depth). How can I build the raster from this two different ...
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71 views

Vector/Raster Intersection - Speedup and replacement for ST_Centroid

I have some raster data which is the altitude above sea level and also some vector data which represents building outlines. What I want to do is grab some buildings outlines and fetch all the raster ...
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71 views

QGIS merge rasters error

I've been trying to merge some raster tiles at work and I've been getting an error message saying I don't have the correct permissions. This works fine on my home pc. Any obvious reasons for this? ...