A tool in some GIS software programs for performing algebraic operations on rasters.

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How to isolate certain raster values using raster calculator?

I have a one band grayscale image. It has values 0-63 within the band. I need to isolate some of those values. Is there a way to do this in the raster calculator? QGIS 2.2//Windows 7
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13 views

map composer grid annotation in DMS format [duplicate]

I have digitized a map using CRS EPSG:4326 in QGIS. In Map Composer I set the grid. I can't get the annotation to display as DMS (degrees-minutes-seconds) rather than DD (decimal degrees) format. What ...
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56 views

How to produce a hazard map using slope and geology information

for my project I need to display a landscape's susceptibility to erosion. I created a slope-map out of my DEM and added the bedrock geology as a polygon-feature shapefile. Now I want to tell ArcGIS ...
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81 views

How to measure Fracture in area using ArcGIS Cut and Fill?

I want to measure fracture in an area.I know I have to use cut and fill tool. But I wonder how to give input for this tool? it has Input before raster surface and Input after raster surface ! what ...
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315 views

How to enter formula into ArcGIS Raster Calculator?

i have the following formula: L = (l/22,1)^m (l = Flow length) m is calculated like this: m = 0,5 when slope is >4 degrees m = 1,2 * sin^1/3a when slope is <4 degrees (a = slope in ...
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613 views

How to reduce all value above certain value using Raster Calculator?

I have a raster with elevations above 2000m that I want to "cut" to 1800m. I cannot quite figure out the correct string and most simple way to do this in the ArcGIS 9.3 raster calculator. I tried ...
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54 views

Efficient manner to buffer streams with multiple attributes?

I need to buffer a very large, complex hydro vector layer based on different water quality designations and surrounding slope. Different water quality classifications have different buffer ...
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85 views

PostGIS ST_MapAlgebra Assistance

I would like to perform the equivalent of the below ArcGIS raster calculator equation in PostGIS using the ST_MapAlgebra function and return it as a tif using ST_AsTIFF. Con(("Sol_gain_clipped.tif" ...
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27 views

Layers and variables are not coming out in the raster calculator tool window

I have many shapefiles in the table of content but layers and variables are not coming out in the raster calculator tool window. I placed the cursor the left of the Raster Calculator window, dragged ...
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323 views

Raster calculator error 000539 - cannot create weak reference to 'classobj' object

I was - like many times before - trying to clip a raster with the raster calculator (raster * 1 with shapefiles as mask). Now - the following error keeps popping up: ERROR 000539: Error running ...
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3answers
341 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 ...
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54 views

Extract raster values under under each polygon buffer in qgis

In qGIS: I have raster file and >100 points. I constructed buffers polygons (vector-->geoprocessing-->buffer) around each of the points. Than I clipped (raster-->extraction-->clipper) the raster file ...
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2answers
505 views

Create an X,Y latitude and longitude grid from an raster

I have a satellite image (LandSat 5), I want create a raster with X,Y coordinates, this is possible in Model Builder of ArcGis 10.0? or other option. I know that the option $$YMAP ($$XMAP) not work ...
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29 views

How to map factors and their relative importance in ArcGIS 10.1 for Desktop?

I want to know how I can calculate a map from a set of factors (in the form of raster layers) and Their relative importance for example: slope 20% lithology 10% . . .
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176 views

the min and the max in raster calculator Arcgis 10.1

Can you help me where I can find or how to calculate the minimum and maximum with raster calculator in arcgis 10.1
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21 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?
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113 views

Measuring polyline lengths running through a raster - is this possible?

I have a reclassified raster layer with 4 values and a vector layer of polylines. I would like to discover the length of the lines running through each raster value, or the percentage of the lines ...
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1answer
69 views

Raster calculator help needed

I have time-series data (rasters) from which I need to calculate the direction of change (increase, no change or decrease) for every pixel from one time-step to the next. I further need an output ...
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1answer
42 views

How can I assign Raster2 pixel value to Raster1 where they overlay?

I want to assign Raster2 pixel value to Raster1(Bigger) where they overlay. Both of them have the same cell size. How can I accomplish this process in ArcGIS Desktop? (Like Raster Calculator ) ...
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136 views

Combining Geological Grids

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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3answers
2k views

QGIS Raster Calculater Syntax

I am trying to use the raster calculator in QGIS to combine a number of rasters. I want to calculate a mean, this is easy: (raster_1@1 + raster_2@1 + raster_3@1) / 3 I then want to create a max. ...
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109 views

Where is qgis getting the NO DATA value from?

I have a project that contains an 8-bit paletted layer (call it the mask layer) and a float 32 single band layer (call this the clip layer). I create a new raster by using the raster calculator, ...
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398 views

Map Algebra - Grass GIS (r.mapcalc) merge two raster with NoData value

I have a slope raster and a road raster. The black pixels in the road raster are NoData values and the pink pixels have a value of 1. They don't cover exactly the same area. I want to create a new ...
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1answer
117 views

How to iterate GRASS region definition?

I am using GRASS r.skyview command (v.7, Windows) to determine "urban canyon effect" on pollution due to the presence of buildings. The command nicely works, unfortunately I need to process a very ...
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43 views

QGIS Raster Calculator dialog doesn't resemble that in documentation

I'm very new to QGIS. Raster Calculator looks (from online sources) like it ought to have all kinds of buttons and fields. Mine is rather stripped down. I have two rasters open, and I just want to ...
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1answer
407 views

Why does Raster Calculator (RasterCalculator_sa) give ERROR 000539 in ArcPy?

I am getting a not executed error for a raster calculator. Here is part of the output: File "C:\projectTemp\FloodAnalysis\floodxsectionanalysis.py", line 107, in makeSeemless ...
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2answers
250 views

Using Python and open source modules, how can I perform Raster Calculator functions?

I would like to perform mathematical functions similar to those you would use Raster Calculator for in ArcMap, however I'd like to do it in Python without using the Arcpy module. I have the osgeo ...
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42 views

Isolate And Save Raster Features From Existing Multivalue Raster Map

I have Cyprus Corine map with 44 different types of land use. I want to run a raster calculator query or any other way to isolate the areas with codes 10 to 22 and 26 to 34, all other values 1 to 44 ...
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49 views

Setting up Raster Calculater for QGIS Python Console: ImportError?

I'm trying to follow the instructions here How to evaluate raster calculator expressions from the console? to set up the python console to to use the raster calculator. I tried: from qgis.analysis ...
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36 views

How to find difference between terrain and groundwater potential map?

I want to find the difference between a terrain map and groundwater potential map to show where it is possible to apply SUDS (sustainable drainage systems) but the units makes no sense. First in ...
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2answers
54 views

Calculating loss of value from a wind turbine on surrounding properties depending on distance

I have to evaluate where installing a turbine would be most efficient, depending on wind speed and price of properties surrounding each cell in a raster. The cost on value of properties is computed ...
2
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1answer
224 views

How to reclassify a raster (tiff) with multiple bands?

i have a raster file containing information about the windspeed average for the year. My purpose is to reclassify the 15 classes based on their rgb-composite. The color is the only information given. ...
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73 views

Creating a new raster based on pixel value of original raster using raster calculator but new layer is not evident

I am trying to create a new raster based on a current raster (w001001 - NVIS) which has one paletted band, with palette values ranging from 1 to 29, with each palette/value representing a vegetation ...
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306 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%" ...
2
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1answer
112 views

extend the size (area) of raster

My problem is that I would like to multiply two rasters using raster calculation tool. Both rasters have values 0 and 1, but the covered area of first raster is bigger (100 x 100 miles) then the area ...
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32 views

How to perform a Con( ) evaluation like “If ”Inras1“ is true then set ”inras2“ to Value X ” correctly in ArcGIS?

I want to set infiltration-rates to different Landcover depending on the slope. I have a Landcover Class Greenalder and six slope- classes with different infiltration rates. e.g. greenalder in slope ...
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2answers
2k views

How to standardize raster output from 0 to 100 using raster algebra?

I am working on generating an integrated moisture index based on the following equation: IMI = (hill shade * 0.5) + (curvature * 0.15) + (flow accumulation * 0.35) Iverson et al. 1997 Another ...
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71 views

How to calculate specified region area with raster in ArcGIS Engine?

By using the "Image classification" tool we can classify the raster image by "supervised classification",but how to calculate their area? I mean, for example, in regard for a produced class '4', how ...
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131 views

Why does the SAGA raster calculator fail when used in a Processing model?

I have a problem with the modeler and the saga raster calculator. When I'm using the raster caculator without the modeler it works fine. When I'm using the saga raster calculator in my model I always ...
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75 views

Why does QGIS raster calculator create a raster with band values=0?

I have a slope raster (value in %) created with the DEM (Terrain models) tool. I am trying to create a new raster showing the slopes > 15%. In the Raster calculator, I used : (my_raster@1 > 15) * ...
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1answer
140 views

How to create Series of Rasters that displays Standard Deviation from Mean?

Cell statistics question for you. I have 100 rasters of raw rainfall data in which the pixels each represent rainfall for that particular pixel on the landscape for a single year during the 100 year ...
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2answers
209 views

How do I generate a random raster (or probabilistic cellular automaton) in QGIS?

I'm trying to create something like a cellular automaton land cover change model using QGIS, in which cells randomly change land cover based on probabilities determined from various input rasters. ...
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82 views

QGIS raster calculator “not equal”?

Is there a syntax for "not equal" in the QGIS Raster Calculator? If so, what is it?
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1answer
51 views

Re-sizing Raster file pixels

I have 2 JP2 aerial imagery files that are incorrectly sized. They are 100x larger than the other aerial images but correctly geo-referenced (starting x, y co-ordinates). I believe the issue is their ...
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1answer
84 views

Raster layer calculator

In PCI Geomatic, I have two raster layer.raster1 identified like %1 and raster2 like %2. if (%1 <= 10) then %2 = 60 elseif (%1 > 10 and %1 <=50) then %2=80 elseif (%1 > 50 and %1 ...
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30 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 ...
4
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67 views

Raster Calculator Bug at start

I use ArcGIS 10.1 on a Windows XP. ArcGIS completely shuts down when I attempt to launch the "Raster Calculator" tool. Has this happened to someone else? Any ideas on how to solve this annoying issue? ...
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1answer
58 views

How to select pixel with smallest number in stack raster using Python script in ArcGIS for Desktop?

I have 6 tiff file in ArcGIS which are identical in term of geometry (same frame, same number of row and column). The pixel value of each tiff file is integer and range from 1 to 4. So if I overlay ...
3
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1answer
477 views

How to reclassify raster inside polygon mask, leaving values outside as they are?

I am in the final stages of a landcover classification and need to reclassify thematic raster values that are inside different polygon masks, while leaving the values outside as they are. Can I do ...
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1answer
349 views

How to “spatially normalize” rasters of different extents to sum values of overlapping cells

How do I add rasters together that are of different spatial extents? I have many, many features that overlap over a large area (entire east coast) and I am looking to sum them "stacked" where they ...