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

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19 views

Raster Calculator Blurring Image Results

I am trying to run a NDVI analysis using raster calculator and the results create blurry or bleeding image, almost as if the map has been dipped in water. Both the bands being entered are very clear ...
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51 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

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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22 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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32 views

ArcMap10.2.2 crashes during raster calculation [closed]

I am using ArcGIS 10.2.2. I want to use the raster calculator to do MSAVI calculation, once I click on OK to run the process ArcMap crashes. Please does anyone know how to resolve this issue. Also the ...
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27 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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46 views

Raster map calculation

I figured out a way to filter a raster by using the r.mapcalculator or the raster calculator. The problem is that I have to use Qgis 2.2 because some of my models doesn't work with 2.4. In 2.2 the ...
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40 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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47 views

How to convert raster negetive pixel value to positive

I was working on ground water Level. I used raster math minus function and the Output raster grid data contains negetive cell values. ma resulting raster contains values ranges from High : 0,187477 ...
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64 views

Error in which.max() : not yet implemented for large objects in R

I am going to create raster by Julian day that observed maximum value of NDVI within a single year. Actually, I want to know which julian day (or raster) has max value in each cells and get result by ...
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68 views

How to create raster map by day that observed maximum NDVI from multiple raster data in R?

I have 11 NDVI raster data, representing single summer. I want to create raster by day (Julian day or name of raster) that observed maximum value. In other words, I want to know which day (which ...
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54 views

Calculating field length in certain directions (raster)

Currently I'm working on winderosion. For my purpose I like to calculate the length of agricultural fields in certain wind direction. I would like to do it for raster. To be more precise: I have ...
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1answer
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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2answers
67 views

DEM mosaic: gaps

I have generated DEMs (bare earth) from Lidar data. For computational reasons, I have processed via ArcGis the lidar files in chunks, so I came up with different single DEMs. After, I used "Mosaic to ...
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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
48 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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57 views

QGIS raster calculator manual or help

There is plenty unknown about how to use raster calculator, for example: how to write NODATA (Null) value in expression is it possible to use within (polygonLayerName) to clip result between shown ...
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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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1answer
55 views

Need to calculate values for a cell based on surrounding landscape

I have a raster file with the urban development of a county mapped out (values: 1=urban 0=not urban). I also have a raster file with several blocks of forested land, each block of land has its own ...
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2answers
110 views

Replacing raster values in one raster with another raster in QGIS … how to?

I have a raster (DEM) and want to replace a few cell's values with the values from another raster in QGIS. I would have done this with the "over" tool in the raster calculator in ArcGIS. Specifics: ...
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2answers
82 views

Change detection with raster calculator

After applying the Diff operator of the raster calculator in arcgis to view changes in land use, would like to see the areas of increased and areas of decreased. This is possible using the raster ...
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1answer
54 views

How to calculate cumulative sum conditionally across raster?

I don't know if this is possible without coding, but I need to: Create a raster file that, for each value in the input raster, sums all pixel values across the entire extent that are less than or ...
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90 views

How to compare two rasters and reclass the greater value(python script)?

I am working on an assignment that requires us to reclass a raster(via python) from two rasters. We need to compare the power received at one cell(on raster1) and compare it to the same cell on raster ...
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1answer
48 views

Translating to Raster Calculator?

I am taking the Learning Spatial Analyst course, which is very good but written for Version 9. I and my students are using Version 10, so some of the syntax for Raster Calculator have changed. Can ...
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52 views

Raster Calculator Workaround in Arcpy for Suitabiliy Analysis

This is my first attempt at a complex stand alone python code. I am self teaching the arcpy module, well at least attempting to. I am having a great deal of difficulty getting my site suitability ...
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29 views

IF (there are three or more developed cells in the Moore Neighbourhood of a cell) THEN (the cell is developed)

Hi I need to create an expression for that principle, so far I have figured out CON ("FocalStatisticsSum" >= 3,"FocalStatisticsSum"="FocalStatisticsSum"+1) Although I pretty sure I am missing ...
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1answer
61 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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1answer
61 views

Define a circular neighborhood for a custom raster calculator function? [closed]

I have a 1 meter resolution raster containing values from 0-3 which represent increasing levels of habitat suitability. I need to identify circular regions that have contiguous pixel values. For ...
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111 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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1answer
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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2answers
78 views

Find the minimum elevation pixels from an elevation raster using arcpy

I want to create a python script to find the minimum elevation pixels from an elevation raster (aster,srtm) using arcpy and arcmap 10.1. The purpose is to reclassify these pixels. I have tried but I ...
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1answer
85 views

Expand raster extent and set expanded values using nearest neighbor sampling

I have run a hydrodynamic model which has given me a grid of surface elevations throughout a bay. I am trying to process the results in ArcMap (or QGIS if needed). My goal is to take the current grid ...
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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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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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1answer
58 views

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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68 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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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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1answer
139 views

How to make polygon volume in TIN surface?

I want to measure surface volume of an area in different elevation layer. For measuring the surface volume I have to make a Polygon Volume as well. I have problem with making this polygon over the ...
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2answers
408 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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3answers
262 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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1answer
26 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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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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1answer
132 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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1answer
85 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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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?
2
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1answer
112 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 ...
2
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1answer
65 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
37 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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1answer
130 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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100 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 ...