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

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3
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1answer
583 views

Random-Forest Classification of 10cm Imagery for species-distribution in R (no point-shapes)

I'm actually trying to classify 10cm-resolution images with the RF-package. I do this to separate some species in the forest, seen on my images. While I was searching for an answer, I found the ...
2
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0answers
55 views

Error in polygonising raster data with QGIS on Mac

I'm using QGis Chugiak on a Mac and I'm trying to converting a raster layer in a vector data by: Raster/Conversion/Polygonize. So, I select the layer needed from the drop-down menu, I give a name to ...
4
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2answers
1k views

GDAL (Python) Aggregate Raster Into Lower Resolution

I have a (continent-scale) raster with 30m resolution in an Albers equal area projection. Each 30m cell has a value 1-34. I would like to aggregate information from this raster into a 1km grid such ...
1
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1answer
89 views

QGIS create raster from cadastre (property lot data) polygon

I have a cadastre (property lots) polygon dataset of a region. Have used rule-base style in QGIS to show different groups of properties in the dataset classified based on their property lot size (ie. ...
2
votes
1answer
958 views

Smoothing raster map

I have a raster map of US Midwest which is very sparse, i.e. the pixels of interest are few enough to be almost invisble when viewed at a scale where all states of US Midwest are visible. I would like ...
3
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1answer
1k views

Max cell value from a stacked raster

How can I find a max cell value from a stacked raster. Rmax <- maxValue(RAD1998.all[[1]]) works fine but Rmax <- maxValue(RAD1998.all[[2]]) gives NA. Of course not in a stacked raster. ...
3
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3answers
805 views

Scatterplot, correlation of dependence and r-square between two rasters

I have two rasters of the same region and of same resolution and I want to plot in a scatter plot their values and compute the best - fit line with r-square. Any idea how can I do this on Arcmap or ...
1
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1answer
83 views

How to crop a vector shapefile according to raster?

I am trying to clip a vector shapefile- points according to a DEM in QGIS. I used GDAL function and polygonized the DEM. Then I ran the Vector-Geoprocessing tools-clip in order to crop the vector data ...
1
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1answer
42 views

How to show number of patches in a neighbourhood?

Given one raster file containing only one zone that indicates patches of vegetation in a city and a shape file containing neighbourhoods for the city, explain how you could create a map that shows the ...
2
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2answers
966 views

Open Raster stored in ESRI V10.0 Geodatabase in QGIS V2.4

Is there a way to open a raster that is stored in ESRI V10.0 Geodatabase in QGIS V2.4. I can open the vector layer, but there does not seems to be a way to open a raster.
2
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1answer
99 views

Get min-max values of a raster and populate two parameters with the values in tool validation script

I am customizing the script tool behaviour of a custom script and would like to get the min-max values from a raster self.params[0] and populate the next two parameters, self.params[1] and ...
4
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3answers
648 views

Plot a Raster of Weather data in Leaflet JavaScript Map without generating server-side tiles?

I want to show different weather data I have as binary arrays on a server using leaflet. But I do not want to generate tiles on the server. For each point in an a array I have the coordinates in ...
1
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1answer
189 views

Raster files are not exact in extent after clipping?

My two layers (chlorophyll-a and Bathmetry) are not exact after I clip my rasters. My bathymetry data (1) is reporting up to 10 decimal places where as chlorophyll-a (2) is only 3 decimal places and ...
3
votes
1answer
664 views

How to overlay a county boundary on a raster file?

I want to overlay California county boundary top of raster layer. Here is is my code: data(coastsCoarse) data(countriesLow) library(gtools) library(maps) library(maptools) library(sp) # Raster ...
2
votes
1answer
86 views

Convert polyline to presence absence raster in arcpy

I have a polyline that I am converting to a raster in arcpy. This is occuring within a loop and at each iteration I change the processing environment to a different area of interest. In this case it ...
3
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0answers
76 views

Raster loaded in ArcMap 10.2.1 not showing decimal places for value

I have an IMG format raster that I am loading into ArcMap 10.2.1. The pixel type and depth, as reported by the Source tab in Layer Properties is 32-bit floating point. The values, as reported in the ...
1
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1answer
75 views

Placing a cost raster in Arcmap Table of Contents in 10.2.2

We have a set of routines that have been used for writing rasters to the ArcMap table of contents from our tools. The code that always worked is this: /// <summary> /// Used for ...
3
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2answers
230 views

Group adjacent polygons with similar (but not same) attributes

In ArcMap 10, I have a few dozen tiffs with cells that represent habitat area that has been burned. Each burned cell has a Julian date of the fire associated with it. I want to end up with polygons ...
2
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1answer
108 views

Extract all raster cells outside a polygon

How does one perform the very simple task of extracting all raster cell values outside a polygon? I've been looking through QGIS for hours with no solution to this simple problem.
2
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0answers
380 views

Problem loading output layer QGIS

Every time I run operations with temporary file output from the graphical modeler, I get the following error message: Oooops! The following output layers could not be open CLIP: ...
1
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1answer
167 views

Finding coordinates of the image corner

I have a .bmp image with a map. For creating image i used a Ingeo 4.4 and function MakeImage() What i know: Height an Width of bmp image dpi Map Scale Image Center's coordinates in meters. What i ...
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439 views

Save fails on raster object created from NumpyArrayToRaster [closed]

I am trying to save an ESRI grid built from a numpy array and am getting an error I've never seen before: Unhandled Exception: System.IO.FileNotFoundException: Could not load file or assembly ...
3
votes
1answer
914 views

SAGA raster calculator, ifelse command syntax problem?

I am trying to get the saga raster calculator in QGIS to spit out all values of a raster that are inferior to 10, and make all other values zero. I think the syntax is correct but I keep getting the ...
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2answers
549 views

Is there any efficient way to create a raster with pixel value representing a unique id calculated based on pixel lat/lon?

I have 10m raster for each state in US. Current pixel value represents something. I want to have 'same' raster but pixel size representing a unique id calculated based on pixel lat and lon. I am ...
3
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2answers
2k views

How are kappa and overall accuracy related with respect to thematic raster data?

I recently calculated kappa (using confusionMatrix{caret} in R) between a thematic raster dataset at 1m spatial resolution and another at 30m spatial resolution. I was interested in quantifying the ...
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0answers
85 views

Multiply Rasters with Scalar Numbers as Input in QGIS Modeler

I built a little model in the QGIS modelbuilder which uses the raster calculator with the command gt(a,threshold) I need to run the model with varying thresholds from 2 to 30 so it would be ...
3
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2answers
2k views

How to generate wind direction raster using its U and V components in arcgis?

I have two raster layers representing the U and V components of a vector wind. I could generate the magnitude raster by applying (u*u+v*v) in Map Algebra in ArcGIS. Now I need to generate the ...
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1answer
923 views

QGIS GRASS Missing Dependancy

I want to perform a view shed analysis in QGIS using GRASS 7 r.viewshed. When I double click on r.viewshed in GRASS GIS 7 commands in the processing toolbox of QGIS I get the following message: ...
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1answer
133 views

Problem with batch mode Saga Raster Calculator

I have to do a couple of raster multiplications for which the batch mode would save me a lot of time. But the only thing I get are rasters that contain nothing but nan values. If I multiply the ...
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0answers
164 views

Easy way to extract raster cells OUTSIDE a vector (Mask) layer in QGIS?

I have a raster file but am only interested in the cells outside a certain polygon. This polygon is very iregular and scattered across the raster. Is there any easy way to extract only the cells ...
2
votes
1answer
355 views

Levelplot(RasterVis) two marginal plot scale?

How can I add/display scale to two marginal plot? RAD1998.all <- stack(list.ras) list.files <- mixedsort(list.files(paste(getwd(), "/1998bil/", sep = ""), full.names = F, pattern = ...
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1answer
43 views

Deleting vector lines beyond image extents using QGIS?

I am using QGIS 2.2 I have one vector line layer (roads) that stretches beyond my base image (see below). I wish to have the roads "clipped/trimmed or deleted" right at the edge of the image's ...
1
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1answer
123 views

How can I shift raster layer for making cloud-shadow mask?

I want to make cloud shadow mask in QGIS. I have raster cloud mask and I have to shift it by X,Y coordinates. Is there any easy solution?
7
votes
1answer
301 views

Graphically depict statistical difference between thematic rasters

The graph shows a regression between two raster datasets with classified tree canopy cover: class 1 = 0-10%, class 2 = 10 - 20% ...class 6 = >60% (Figure 1, Figure 2). The spatial resolution for ...
0
votes
1answer
62 views

levelplot index issue

levelplot with static index works fine but not in a for loop. What's wrong with my code? Static index: png(paste("1998",outlist[[1]],".png",sep="")) levelplot(RAD1998.all[[1:4]]) dev.off() ...
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2answers
711 views

R -plot 12 images per plot or save 12 images per image file in R

Here is R script and my question is How can I plot 12 images per plot or save 12 images per image file because I have total 864 images. RAD1998 <- raster(paste(getwd(), "/1998bil ...
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1answer
641 views

AttributeError: 'unicode' object has no attribute 'save'

I'm trying to multiply my raster to 100 from my ListRasters. I've adapted the code (especially the for loop portion) also from this site. Now, I'm encountering an error at the last line, when saving ...
3
votes
1answer
194 views

Highest DEM pixel in polygon

I'm working with QGIS and have a big DEM raster layer with height information and a vector layer with many polygons, representing 1 x 1 degree tiles. Now I want to find for every polygon the highest ...
2
votes
1answer
196 views

(How) can I write string data to a raster with Python/GDAL?

In Python, I have a NumPy array of string values (categories of some variable) that I'd like to write to a raster file (.tif or .img) using GDAL. The impression I get is that it's not possible to ...
2
votes
2answers
321 views

QGIS raster clip error: Cutline not of polygon type

I have a raster file and want to clip it, but I'm getting this error: "ERROR: Cutline not of polygon type" what does this error mean and how can I resolve it?
2
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0answers
65 views

Align & Sum Grids in Python

I have two grids. One, call it A, is 4320x2160 cells and spans the whole globe. The other, call it B is 8640x3432 and spans the circumference of the globe, but is clipped toward mid-latitudes. Both ...
2
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2answers
126 views

Reclassify a rasterList and sum the reclassified value from each Pixel

I'm trying to write a script in arcpy which reclassified a List of Rasters. This rasters are made by another tool before so there is already a loop. Actually I get the error 000582 and before this ...
3
votes
1answer
644 views

How can units be defined in QGIS for the Rasterize tool?

I am using QGIS 2.4 (Chugiak) via the kyngchaos build for OS-X. My question is--when using the Rasterize tool to convert a point vector layer to a raster and using the "Raster resolution in map units ...
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0answers
170 views

PostGIS Raster functions not working

Hopefully I have a simple question that I'm not phrasing correctly in google. I'm trying to learn about storing and producing rasters in PostGIS. There are tons of examples and documentation online ...
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1answer
183 views

Java how to create geotiff from points

I have an array of objects where each object has three fields: lat, lon, and category. It is essentially pixels that have been given a land use category. I cannot figure out how to turn this data into ...
5
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0answers
263 views

How do I parse the file format for attributes in Raster Product Format (RPF) maps and imagery?

I'm trying to implement an open-source NITF reader (using only java, no external libraries such as GDAL or NITRO), and its mostly going OK. However I'm having trouble understanding the RPF extensions, ...
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0answers
46 views

Looking for a QGIS solution to make aerial imagery ArcSDE compatiable [closed]

Would like to avoid having to use 3d Analyst and use free raster tools in QGIS or elsewhere to make aerial rasters ArcSDE compatible. This 18 page work flow is what I am trying to use. Any suggestions ...
2
votes
1answer
91 views

Speeding up loading raster

I georeference a tif image and then I clipped that image in a mosaic. I did a index of these images but when I load them is very slow(7 seconds or more to display the first tile). How can I do to go ...
2
votes
1answer
152 views

Error reading large virtual raster with rasterio: “Cannot invert degenerate transform”

I've created a virtual raster using gdalbuildvrt, which covers a large extent (England) at a high resolution. The data is fairly sparse, focused around the coastlines with no files covering inland ...
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0answers
194 views

Correlation between point feature (disease) and elevation

I have a problem! How can I calculate the correlation between point feature and Dem raster? Hypothesis: disease prevalence in high altitude is more than low altitude. I must do this in ArcGIS 10 and ...