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

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6k views

How to calculate raster statistics for polygons?

how can I calculate sums, averages etc of raster-points (multi-band) per polygon of a vector-layer. I was told that this is called "zonal statistics". I tried that with QGIS first. There is a way to ...
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1answer
59 views

IDW with QGIS from a vector points file within a mask

Given two inputs: A shapefile: points A raster: mask I want to interpolate the points within the extent of the raster except the NoData pixels that i want to use as a mask. NoData pixels are the ...
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2answers
139 views

Minimum mapping unit for raster on ArcGIS

So I have this huge national wetlands raster and I'm trying to set a minimum mapping unit of 5 acres. Meaning I want to delete clusters of pixels that are smaller than 5 acres. But the raster's ...
2
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0answers
33 views

How to calculate the slope with isolines/raster?

I'm trying to calculate the slope (in %) in ArcGis 9.3, but don't remember how it works. I already did it some time ago, but this time it doesn't work... I used a shapefile with Isolines (see ...
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3answers
805 views

Creating spatially projected polygon grid with ArcMap

i need to create a grid with 1x1 square kilometres cells in ArcMap. The operation located in Data Management Tools -> Feature Class -> Create Net is almost what i need but in the parameters, i can't ...
2
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2answers
82 views

Convert line shapefile to raster, value=total length of lines within cell

I have a line shapefile representing a road network. I wish to rasterize this data, with the resulting values in the raster showing the total length of the lines that fall within the raster cell. The ...
0
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2answers
63 views

How do I mask a raster in TileMill?

I've tried just about every single TileMill compositing operation on the vector and raster layers in question, and I have to admit that I can't figure it out: How the heck can I mask a raster with a ...
0
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0answers
22 views

Script Efficiency

I have been working on a script to read pixel values and print the values out to a text file. This is currently working but takes around two hours with a 6.6gb file. This is to replace an older script ...
2
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1answer
42 views

Open Source counterpart to Euclidean Allocation

I'm looking for a function that can perform something similiar to the Euclidean Allocation process in arcGIS ...
9
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2answers
196 views

Are “gridded data” and “raster data” the same thing?

I'm working on a project that will involve both "raster data" (aerial imagery and DEMs) and "gridded data" which I understand to be other kinds of numerical measurements taken at grid points, and ...
10
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5answers
1k views

Multicriteria Analysis : how to?

I have to do a multi-criteria analysis to answer the question : "which is the best lot to develop". A few of the criterias are : distance of the nearest bus stop (point layer with bus stops) ...
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6answers
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How Do You Remove No Data From A Raster (.sid)?

I have an Image.sid that has a white border which is No Data. I've tried using Clip Raster Tool with no success. I've also changed the symbology value for No Data to be transparent. I'd like to ...
2
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0answers
49 views

Hyperspectral Data in ArcGIS Desktop

The public organization I work for has some archived hyperspectral data (.raw - radiance, non georectified). Has anyone processed hyperspectral data for consumption within ArcMap? If so, what sort of ...
2
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2answers
132 views

How to draw a square from 2 coordinates?

I have a CSV file with the following output id, x min, y min, x max, y max, value 1 , 0 , 0 , 100 , 100 , 5 2 , 0, , 100 , 100 , 200 , 10 3 , 100 , 100 , 200 , 200 , 15 4 , 100 , 0 ...
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2answers
43 views

How to take cosine squared of raster using python

I have an equation y = cos^2(x) where x is a raster. How can I write this equation in python?
2
votes
2answers
54 views

Find coordinates of given raster value

I would like to get the coordinates of a raster cell with a given value. I suppose many cells can take the same value, in which case several coordinates should be returned. In my first problem I'm ...
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0answers
12 views

Error Using Open Layers 3 Web mapping Applications [duplicate]

As being new to website development, i have been able to display map on my website, but I want that i should only zoom to some specific places of india on loading of web pages. Can somebody please ...
3
votes
1answer
265 views

GIS beginner - interpolating contour lines from TIN-model vs. Grid in ArcGIS

I am a complete beginner in GIS and taking a class right now, and we are doing some assignments in ArcGIS - ArcMap. In one of them we were given a shapefile with heightpoints. These had been manually ...
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1answer
37 views

What is a better idea for modelling a fault plane than as TIN? [duplicate]

I am working on a project which runs on ArcGIS platform using VB.NET. It is to model a sub-surface fault plane (currently a plane rectangular model with some dip) and then to find required distances ...
1
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1answer
174 views

NAs not allowed error message in attempt to plot raster object in R

I have imported a clipped raster (performed in ArcGIS 10.1) from the National Landcover Dataset into R, but when I try to plot I get the following error message. Error in .readCellsGDAL(x, ...
3
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2answers
32 views

How can I draw an outline around my raster classes

I have a raster created from polygon shapes from a social survey of fishing areas in ArcMap. I have classified my raster to 3 classes High,Low,Medium. I want to draw a border or an outline around the ...
4
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2answers
2k views

How to read this GRIB data [closed]

on this open FTP server (ftp://ftpdatos.aemet.es/modelos_numericos/hirlam005_peninsula/) you can find HIRLAM models from the Spanish meteorological service. The documentation in the LEEME files (in ...
5
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1answer
107 views

How to determine the optimal raster resolution when interpolating a surface from points?

I'm looking for guidance on how to determine the desired output resolution, when interpolating a surface from irregularly-spaced point samples. I have a series of boreholes taken across a city, and ...
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1answer
39 views

Change Data Source of Raster Layer Added to Map Display? Unexpected default

I have a script that I'm using to generate raster maps and automatically add them to the map display, but when they are added they are sourced to a temporary location. I use the same code for ...
1
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1answer
39 views

Get value of clicked raster cell

When I open a raster file in QGIS (for example a GeoTiff file), I want to quickly check the value of a clicked raster cell. I found there's an 'identify' tool in the toolbar, but when I click with ...
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3answers
454 views

How to infinitely extend MapInfo grid layer?

We use a semitransparent grid layer (.mig file) to show 'hotspot' intensity in MapBasic (MapInfo. Because the grid is just a rectangle, this looks ugly. See for instance: . Now MapInfo allows grid ...
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0answers
36 views

TIF file creation from shapefile in GRASS?

Does anyone have any idea how to get around this problem? I've been looking for a solution to no avail. I'm trying to convert a shp file to a grid, and the tif is hanging up. Output raster layer: ...
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0answers
17 views

Smooth and boundary clean raster (GRACE) Data

I have some GRACE data that I would like to smooth out and generalize/aggregate the boundaries to look like the maps shown at this website. I've tried playing with filters, converting to integers ...
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2answers
45 views

getting to grips with raster data: Tutorial needed!

I always have trouble understanding the different characteristics of raster data formats - Bands, RGB, Alpha, Color tables, Classification, Stretching, single color setting etc. Can anyone offer me ...
0
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1answer
52 views

how to batch reclassify rasters with percents range

Using Model Builder I need to reclassify slope rasters with percents range value. I have read and ask here batch reclassify rasters with different elevation ranges, but I still need more explanation. ...
2
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1answer
172 views

Combining Geological Grids and extruding between them?

I have a situation where I have 3 Geological grids, each showing a different horizon + the Seabed Grid. I need to extrude between these grids in order to make the 3D polygon for the geological ...
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0answers
37 views

set extent for jpeg programmatically

I feel like this should be easy, but how can I set coordinates for a jpeg image using Python? I have a python add-in that draws a polygon and then uses its geometry to post a query request to a REST ...
3
votes
1answer
37 views

1m cell size equivalent value in decimal degree

I'm doing re-sampling pixel size in ERDAS 2014,I'm using input image(Indian terrain) in GCS_WGS_84 projection. Now I have to keep out put cell size as 1m,what is the 1m equvivalent value in Decimal ...
2
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1answer
47 views

Build raster with multiple attributes based on 3 input rasters

I am trying to make a new raster based on three input rasters which have the same cell size and the grids align perfectly. I now want to construct a new raster, which for each cell, has three ...
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1answer
80 views

how to permanently add raster to satellite image in qgis

As mentioned in the title i need to integrate a raster to a satellite image but have no idea as to how to do this. I tried the add grid function and it works nice but is not permanent. I insert it ...
0
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1answer
42 views

Is it possible to create one raster elevation layer from two different point layers in QGIS?

I have two layers with X,Y,Z data. The data overlay only partly. Is it possible to create one raster layer with elevation data using the 2 sets of data but without merging them first?
0
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1answer
22 views

Problem in adding raster layer from arcpy

I am using the following code to add the raster layer using arcpy in arcmap def AddRasterLayer(path,layerName): layer=os.path.join(path,'new'+str(layerName)+'.lyr') ...
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0answers
18 views

Extract values to point - values not being extracted

I have a single band raster. When I use the information select tool I can see pixel values. I also have a shape file made up of points sitting over the raster. I want to extract the pixel values from ...
0
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0answers
23 views

Clipping MrSID raster image, without decompressing clipped raster, in ArcGIS Desktop? [duplicate]

I am using ArcView ArcMap10 and when I clip a raster using tools/data management tools/raster/clip. The Clipped file ends up much larger than the original file. Specifically I am trying to clip a ...
1
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1answer
42 views

Removing disconnected cells in a stream network raster using ArcGIS

I've got a predicted stream network raster with cells values 0 (not a stream) and 1 (is a stream). My end goal is to create a network of connected polylines, but unfortunately there are some areas ...
2
votes
2answers
95 views

Arcpy Slope Analysis Script

I'm trying to run slope analysis in ArcGIS. I have written an ArcPy script that converted feature layers to raster files. Now I have a list of rasters (each with a unique name) in the table of ...
1
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1answer
35 views

Wrong coordinates after Usage of NumPyArrayToRaster(…)

My Project I am currently working at should enable cellvalue manipulation on raster files using ArcPy. My Script works fine except I am not getting the right Y-Values (northing values) for the ...
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0answers
18 views

Image pyramid have wrong colors in Geoserver (but the tif-files looks fine)

Just want to start off with saying that I'm fairly new to geoserver and the fix to this may be very simple. So have managed to create an image pyramid out of a ~7 GB ECW file. The files are fine ...
3
votes
3answers
131 views

QGIS Mosaicing with null values in images

I have a set of landuse landcover data which needs to be mosaiced. Whenever i try using QGIS Raster>miscellenous>merge tool. giving no datavalue as '0', it returns either (A) ' Traceback (most ...
7
votes
1answer
2k views

Smoothing raster features into polygon

I have raster data representing urbanized areas, which I'd like to trace and convert to a polygon. Using ArcMap's Raster to Polygon tool, I'm able to get something close to that. Unsimplified: ...
2
votes
0answers
42 views

How to Interpolate very large datasets in QGIS?

I am working with a very large set of point data, (XYAttribute) which I wish to display as a raster. I've been using Interpolate, this is successful but very slow. I have other programmes that ...
2
votes
1answer
110 views

Display a raster stack with several bands in ArcGIS?

I have already made a raster stack (5 bands in one TIFF) of my multitemporal Landsat images in R and have also clipped a smaller region of every raster stack for each image. Now I want to do some ...
3
votes
2answers
42 views

QGIS ASCII Grid output problem

I have this .asc file of maximum temperature of a local place. This file is a result of vector to raster (GeoTIFF) conversion then GeoTIFF to ASCII grid conversion, both using QGIS. Here is a snippet ...
2
votes
1answer
32 views

Failed to execute floating raster to integer raster

im facing a problem in converting Floating to Integer Raster by using"spatial analyst tools (arc toolbox) > math > Int" . However, it shows warning of "error ERROR 999998: Unexpected Error. Failed ...
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1answer
18 views

How can I check the resolution of my .img raster file in ArcMap?

I'm just learning ESRI's ArcMap and I just wanted to know where I can find the resolution of a .IMG raster layer.