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

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367 views

Gdal creating raster rotated wrong way

I have been trying to read in a stack of images for a timeseries and created an output raster that contains the max pixel values of the timeseries. The arrays were created using numpy img_stack = np....
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961 views

QGIS DEM (Terrain models) Mode Slope creates wrong data [duplicate]

I have a DEM raster file downloaded from the USGS site. The file can be downloaded here. I am trying to create a slope raster in percent with the DEM tool in QGIS. The GDAL command is the following: ...
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2answers
282 views

How to use the raster calculator in the processing modeler of QGIS

I am trying to create a easy way to do raster analysis by building a model for two way raster calculations. I have two raster layers that I want to combine into a single raster. For now I've done this ...
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0answers
759 views

Precision for an FGDB raster dataset?

I would like to know the precision for an ArcGIS raster stored within a file geodatabase (FGDBR format); I can't seem to find this information anywhere in their documentation (apologies if I have ...
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1answer
444 views

Renaming multiple rasters with ModelBuilder gives errors 000622 and 000878?

I have 101 raster images stacked inside a folder. The Rasters are of arcinfo grid type (*.asc) while having a long string name 'NW2D_T100_05_base_depthXXX.asc' where XXX ranges from 000 to 100. What ...
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1answer
80 views

How to deal with empty corners in raster when calculating fragmentation index

I have clipped buffer area around coordinate from one big raster (forest cover). Such created raster was loaded in R where PatchStat function (library SDMTools) gives fragmentation index. After ...
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2answers
61 views

Creating Many Uneven Buffers

Qgis 2.2, Windows 7 I am looking to create buffers around city lights (the raster). Currently, I have simple polygon buffers around the point layer (oecdminusa), but this is not accurately capturing ...
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2answers
1k views

Converting shapefile to raster: Character attributes

I've got a shapefile that I would like to convert into a raster, but the trick is that the attribute I want a raster version of is character data. I'm familiar with geoprocessing using GDAL (in the ...
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323 views

Getting Zonal Statistics of Overlapping Circles?

I have a Buildings (polygon) shp file and a DSM. what I wanted to do was to get the pixel values for all the vertices of those buildings, and find another pixel value just around those vertices (say ...
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161 views

Raster format similar to ECW

I need an alternative to the ECW format that we currently have for a new series of Ordnance Survey maps. The ECW format looks clearer and less pixelated than the new maps in Tif format (in QGIS). ...
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94 views

Anyway to make Raster look like distinct Polygons

Is there any clever way to make a raster have a more clean vector look to it with straight polygon looking boundaries between classes when adding symbology to the data? Sure I could convert the ...
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122 views

Calculating Percent Overlap Between Distribution Maps

Hello there, I am currently trying to calculate the percent overlap (basically the total amount of overlap where these two species come into contact) between Lithobates catesbeiana (first image) with ...
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1answer
221 views

Raster Attribute Table Where Each Pixel = 1 Row

In ArcGIS, is it possible to create a raster with an associated attribute table where each pixel is represented by a "row" in that table. I would like to specify unique attributes for each raster ...
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1answer
272 views

Understanding the cell size argument in the kriging tool, ArcGIS

I'm not quite understanding the cell size values that a given raster has. I've been doing some kriging interpolation on very dense point data and if I leave the cell size parameter blank, it's cell ...
2
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1answer
60 views

Polyline frequency to raster

I have some animal tracking data in the form of a polyline shapefile and want to convert this to a raster so that each pixel is given a value of 1 for every instance in which a line crosses it. I've ...
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2answers
379 views

raster standard deviation stretch python script

I am looking for ways of applying a permanent standard deviation stretch to rasters via python script. Are there any arcpy raster stretch functions? I was looking for a reference but could not find ...
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1answer
975 views

How to add tree height values to raster / vector data?

I am new to working with raster data and I am trying to teach myself a few things. I have what I think is a simple problem but I can't seem to figure this one out after a few hours of searching Arc ...
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1answer
103 views

Why do the raster band values have different values than the raster statistics?

I am working on a raster file (1 Band). According to the raster metadata, my minimum value is 0 and maximum is 7458. This seems to be confirmed by the Style options that return some category values ...
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2answers
743 views

How can I get my raster analysis to produce a larger extent in ArcGIS

Ok so the situation is as follows. I have an vector shapefile and within that area there are three points. I converted the points into raster and now I want to do a Euclidean distance analysis in ...
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1answer
625 views

Find maximum and minimum value in a list of raster

I trying to write a standardisation script that standardises each raster dataset in a list of rasters by the highest and lowest values found in the list of rasters. The standardisation code is as ...
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6answers
4k views

Continuous color band for a raster legend in QGIS composer legend

I'm looking for a way to insert continuous colour legend for a raster layer. I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values ...
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1answer
87 views

Extract information of a raster overlayed on another raster with a lower resolution directly in python

I have two aligned rasters with the same extent, one has a resolution of 5 meters and the other of 125 meters. I would like to place the 5 meter one over the 125 meter one and assign to these smaller ...
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1answer
168 views

Map algebra for loop

I have never coded in Python before and I am trying to loop a simple map algebra equation across 365 rasters. I am trying to calculate total water flow over cells but in the raster I have a negative ...
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1answer
631 views

How to create graph out of two layers using ArcGIS 10.1 for Desktop?

I would like to create a graph of two layers I have. on one hand its the land price of a certain area and on the other a layer with a crime rate. first of all, the layer with the land prices doesnt ...
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1answer
2k views

Fill sinks error in arcHydro

I am working on a project that is modeling runoff at a county level. The DEM used is lidar derived and has a 5 ft resolution. The general workflow I am flowing is Sink evaluation Sink Selection (to ...
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103 views

How to extract raster using corresponding polygon using ArcPy?

I have to perform a simple raster extraction, but I can't find the way to do it. In a polygon layer, I have watersheds with their ID's. And in a folder, I have rasters, each one corresponding to a ...
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1answer
259 views

How to combine Boolean and Fuzzy logic?

So I have a set of 5 Fuzzy Memberships and a polygon feature class, to which I already added a yes/no field. For the final map, I need to combine/overlay all Fuzzy Memberships and the rasterized ...
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3answers
1k views

Topography: How to get the x,y,z coordinates of highest or lowest point/pixel of a raster GIS?

Given a .tiff topographic raster image with mountains and deep sea, I am looking for the x,y,z specifics of the highest or lowest point. The x,y,z values being: altitude (z-coordinate) latitude (y-...
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3answers
1k views

Gdal: how to get the max and min altitudes of my topographic raster?

Given a .tiff topographic raster image. How to get the altitudes of the highest and lowest point/pixel ?
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3answers
3k views

How to extract X Y coordinates and RGB from pixels using python in QGIS?

I'm trying to white a Python plugin in QGIS (2.2) to get, for each pixel of a raster image, its X Y coordinates, as well as, its RGB (3 bands) values. At first I opened the raster file using: rlayer =...
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42 views

How to modify extent (layer) for Fuzzy Membership analysis?

When applying the Fuzzy Membership, how do I modify the extent (layer) to which it is applied? I don't mean showing the extent, but changing the values (mid point & spread) to a different layer?
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1answer
2k views

R raster Package Moran's I interpretation

I am using raster package to calculate the local Moran's I . The example gives the range of Moran's I between - 1 to 2.47. On my own data I have see the value range -3.070423 - 7.228558 How can Moran'...
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4answers
8k views

Combine overlapping rasters with priority to values of specific rasters?

I have 5 rasters that cover a large area. I want to combine all 5 into 1 raster. Each raster has data for portions of the total area that none of the other rasters cover. Raster C overlaps A,B and D. ...
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31 views

How can I remove dipoles from rasterlayer in QGIS 2.2?

I work with geomagnetic survey data. When convertet into a rasterlayer, every object with a high magnetic potential (for exampel an iron-nail on the surface) is shown as very sharp anomalie called ...
7
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1answer
381 views

How can I conduct Geographically Weighted Analysis using an exponential decay function?

I have some points (representing 30 study sites) and I want to calculate the weighted mean of several variables (landscape layers) using a negative exponential decay (weights function) to give more ...
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1answer
119 views

Zonal Statistics Freezing QGIS 2.2

Running on Windows; 8gb memory, 500gb HD, i5 cpu; Raster file: 250mb I am having a problem with zonal statistics advancing past 17%. I am trying to run statistics on a crop grown in certain counties. ...
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237 views

I had an error in Gdalwarp and i don't know the reason

I was trying to warp a raster using a mask and shift it before clipping but when i exectute the command bellow in Qgis/PyQt using QProcess: gdalwarp -s_srs "+proj=merc +a=6378137 +b=6356752 +lat_ts=0....
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2answers
841 views

Mask image based on no-data pixels in another image with different projection - GDAL or Python

I've got a land cover image which covers the whole globe, and a satellite image which covers a very small part of the globe. These two images have different projections, co-ordinate systems and pixel ...
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72 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
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1answer
790 views

Interpolating contour lines from TIN-model vs Grid in ArcGIS for Desktop?

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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73 views

problem saving GRID to .img keeping original names (export by attributes)

I am really new in Python programming. I try to make a loop for Extract by Attributes tool in ArcGIS 10.1. I have a huge dataset of raster (760pc) and I want to extract a specific value. This part of ...
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1answer
446 views

Plot a Raster in R with white space for NA values

I want to produce a .png of a raster with background values plotted as white space. Below you can see the current state of the plot. As you can tell, the pixels which should contain NA values, ...
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231 views

Workflow with raster in Qgis 2.2

I'm trying to build a workflow with the Qgis 2.2 processing toolbox. I want to clip a raster layer with a vector layer using the GDAL tool "clip with a layer mask". But it doesn't work. The error ...
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2answers
635 views

References to code IDW algorithm

Hi I'm new to interpolations. I'm looking for documentation to understand how inverse distance algorithm works and how to code it. My intention is to code IDW algorithm in JavaScript to see if it is ...
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0answers
72 views

Define uphill side of roads and buildings

I have a big raster of a mountain region and I need to extract the uphill side of roads and buildings, from these elements to the pick of mountains. For a road I know the uphill side changes in ...
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1answer
688 views

R Raster package loop over pixels

I want to perform a trend analysis for each pixel over it's time dimension. Therefore I wrote a loop over each pixel doing the calculation but this is extremely slow. I am sure there must be a faster ...
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1answer
159 views

How to use USGS Bulk Download on EC2 linux Server?

I am interesting in downloading Landsat 8 rasters to an Amazon EC2 instance and would like to know how to do it. I already install USGS Bulk Download but I do not know how to use it in terminal mode (...
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105 views

write rasters from estudm2spixdf with significant digits

I have estimated my kernels using kernelUD from the adehabitatHS package which produces information from multiple animals as a class estUDm. I am trying to write out from R to get into ArcGIS the ...
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24 views

How do I randomly alter a raster with som correlation

I need to randomly alter an existing raster. The original raster is essentially a topography map that measures its values around a normal distribution ranging between 0.5 and 1.5 The new raster ...
3
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1answer
196 views

Cell Statistics in QGIS

Cell Statistics in ArcGIS will calculate the mean (or statistic of choice) among multiple rasters on a cell-by-call basis. Can QGIS do this? If so, how?