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

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263 views

An error in raster calculator in Arcgis

I wrote and ran this formula in raster calculator in ARCGIS. But the following error gets me into trouble. Does anyone have a suggestion to overcome this? Here is the formula I wrote and the error ...
2
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1answer
118 views

Calculating Topographic Exposure with Raster Calculator

I need you help trying to calculate Topographic Exposure (TOPEX) on a DEM in ArcGIS. I am trying to figure out wind exposure on a DEM with 25m cells. There is a great blog post where someone explains ...
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1answer
49 views

QGIS Slope Classification Issues

I am very new to QGIS for the primary purpose of creating a slopes layer so we know where slopes are above 15% or 20% or whatever we finally decide. I have used our DEM to create a slope geotif and ...
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1answer
108 views

Floating point calculations in QGIS

How do I manage floating point calculations in QGIS? I have carried out 3 consecutive calculations on landsat bands. I end up with 32 bit floating point rasters on which I can't carry out a 4th ...
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1answer
159 views

problem with layers and variables box in raster calculator

I have a problem with layers and variables box in raster calculator. The layers and variables box does not exist in the raster calculator window! So I can not add any raster to the expression. I am ...
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1answer
54 views

Issues calculating range with QGIS 2.0 raster calculator

I would like to calculate a simple range using the QGIS 2.0 Raster Calculator, but am getting strange results. I believe I am not using the correct syntax. To get all values between .003-.5, I ...
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26 views

How I can sum 360 raster files in a folder with the Arcgis raster calculator?

In a folder I have 360 precipitation raster files and I want to sum them all to the raster calculator
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29 views

QGIS – Raster Calculator: Using flat (no data) areas of an aspect-raster in the raster calculator

I´m playing around with the Raster tools, following more or less the qgis-tutorial but using my own data. When I calculate the aspect of a DEM, flat areas are (logically) left without data. However, ...
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1answer
41 views

Specify a field in attribute table with raster calculator

How can I specify the attribute field to use in the raster calculator of ArcMap 10.2? In 9.x, I used the dot notation. i.e. To use the "New_Value" field, I could do the following: ...
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48 views

Cause of ArcGIS Raster Calculator Parsing error <type 'exceptions.SyntaxError'>: invalid syntax?

This is my first attempt at much code in the raster calculator of ArcMap 10.0, but I think I'm close. I have nine rasters (A-I below) and want a new raster with value = 1 where any of the rasters ...
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1answer
49 views

How do I replace cell values of a raster using values of another raster with differing extent?

I have two rasters (raster1 and raster2). The raster1 extent is smaller than raster2. I want to replace the value of raster2 pixels using raster1 pixels. How can I replace the values?
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67 views

Raster vs. Raster Scatter Plot in ArcGIS

I created two raster datasets from the same world view 2 image. One dataset is NDVI, the other is a normalized surface water index (NDSWI). I would like to create a scatter plot for a pixel by pixel ...
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19 views

Error 000539 - Band_# not defined

I'm trying to do an NDVI analysis of a some World View 2 imagery. It seems no matter what if I enter the term Band_# for any of the 8 bands I get the same error.
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1answer
87 views

Problems running model in QGIS

I am trying to make a batch model to convert band 2 and band 1 MODIS 8 day composites into NDVI. The input files are in tif format, but I want the output to be saved in Idrisi .rst format. I am ...
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1answer
46 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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1answer
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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72 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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0answers
59 views

How do I make a path cross the most possible classes in a raster?

I want to create a function and possibly use Arcmap tools to create something similar to Cost Path. Instead of just choosing the LCP, it must cross through the most different integers. Let's say I ...
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0answers
18 views

Running focal statistic with iterator in ModelBuilder?

I need to extent the Value of a grid (water mirror elevation) within the nodata area until reaching a specific barrier (the limit of the watershed), in ArcGIS 10.2 for Desktop. I am using this: ...
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10 views

Error 000539 I am new to Raster Calculator and can not figure out what is going wrong

I am new to Arc and 10.2 but can not seem to figure out why this won't work. Executing: RasterCalculator Con(("SLOPE_SLO.tif" >= .015) & ("SLOPE_SLO.tif" <= .15,1,0)) ...
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29 views

Raster Calculator

I have a slope dataset. How do I calculate the real surface area for this slope dataset using the raster calculator. This is the example I was given: orthogonal area of a raster cell in square ...
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0answers
28 views

plug logistic regression equation into Raster Calculator when one predictor is nominal

I am conducting a study that aims at building a Logistic Regression model for land productivity quality (binary dependent variable: good, no good) using different predictors such as slope, elevation, ...
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53 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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0answers
99 views

Raster Calculator error

I'm trying to use raster calculator inside Model Builder to get rid of null values, but I'm hitting a snag. I'm using the expression: ...
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0answers
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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249 views

How To calculate raster land cover inside overlapping buffer zones?

I am working with a raster land cover file that consists of several land cover types (e.g. forest, buildings, grass ect.) in total there is 40 different land cover types. I have 1200 bufferzonen ...
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318 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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40 views

Arcpy raster calculation producing random no data cell in output

I've been trying to get the raster calculation below to work using python: import arcpy from arcpy import env import os from arcpy.sa import * arcpy.CheckOutExtension("spatial") KSat_mm = ...
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124 views

Help with scripts for processing raster files with the raster calculator in QGIS

I am trying to process some raster files using python scripts in Qgis 2.20, and I have been having trouble finding any documentation on using raster calculator in scripts being run in the processing ...
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50 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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53 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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20 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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35 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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267 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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31 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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69 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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125 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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74 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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29 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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96 views

North aspect raster with QGIS Raster Calculator

I have QGis1.8.0-Lisboa and the Raster Terrain Analysis Plugin on Mac/OS. When I want to build a raster layer of an aspect group with the Raster Calculator (e.g.: "aspect@1>=45 AND aspect@1<135" ...
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0answers
50 views

Creating raster from raster subtraction

I am trying to create a raster from the subtraction of two other rasters. I am aware the process involves several steps, therefore I would like to know: What is the command for raster subtraction? ...