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

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raster calculator fail to sum?

I am having a question about the raster calculation as I am trying to create a tool which I want to link with my python script to sum weight rasters but if failed to do so. here is my code: #*the ...
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3answers
2k 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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2answers
115 views

How to update raster pixel values based on another raster with conditions in QGIS?

I have 2 land cover rasters. I want to update parts of the first raster with values from the second using QGIS. The workflow should be like this: 1. Select values equal to 30 and 34 in the first ...
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1answer
54 views

Combining information from multiple rasters into aggregate raster and populating fields accordingly

I am stuck on how to best combine the information from multiple rasters into one raster. Specifically, I am working with a time series of raster files, whereby each raster corresponds to a different ...
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1answer
54 views

Calculating maximum value in Raster Calculator of ArcGIS for Desktop?

I have MODIS NDVI data of four months and I have to calculate NDVImax. I am using the Raster Calculator of ArcGIS and have been using various algorithms like [MAX ("june2000", "july2000" , ...
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53 views

Using Con in Raster Calculator of ArcGIS for Desktop? [closed]

I have two images, "dvel.img" and "evi.img", and i want to extract water related pixels. The condition is: (("dvel.img" <= 0.05) & ("evi.img" <= 0.3)) I want to get an output by putting ...
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1answer
24 views

In ArcGIS raster calculator can you access the individual cells surrounding a central cell like you can in GRASS r.mapcalc

Is there a way to do the following in Raster Calculator in ArcGIS? In GRASS r.mapcalc you can access the cells surrounding the current cell by writing inputRaster[a,b] where a and b represent the ...
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49 views

Meaning of ERROR 000539: Error running expression: rcexec() <type 'exceptions.ImportError'>: No module named os?

In Raster Calculator using: (FocalSt_meanDEMtif5-FocalSt_minDEMtif1) / (FocalSt_maxDEMtif2-FocalSt_minDEMtif1) What is the meaning of ERROR 000539: Error running expression: rcexec() : No ...
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29 views

Compare euclidean distance with network distance

I have a raster file with euclidean distance. It contains information about how long it takes for a chopper to arrive to certain destinations. I then have a polygon made from a service area with ...
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636 views

Performing Raster Calculator functions using Python and open source modules?

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 ArcpPy module. I have the osgeo ...
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1answer
63 views

Using decimals in ArcGIS Raster Calculator tool?

I would like to create a new raster by using the following regression equation in the Raster Calculator tool in ArcGIS 10.3: Outputras=0,000826345+(0,000203494*"Roads_density.tif") ...
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46 views

Calculating Geometric Mean in Raster calculator

I am calculating Geometric Mean for land degradation mapping. I am applying following formula in ArcGIS 10.2- ("GW.img" * "LULC.img" * "Rain.img" * "Temp.img" * "Wind.img" * "NDVI.img" * ...
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13 views

How it can be made a spherical cap surface with qgis raster calculator

I would like to make a test in QGIS raster calculation: I'd like to make in a flat raster surface (0m as elevation) a kind of hill or dome with the spherical cap geometry formula. P is the point ...
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0answers
29 views

Do rasters have to be of same extent for the QGIS Raster Calculator?

I am trying to use the Raster Calculator but, I get a raster with Nan values. My rasters are in the same projection system but, one of them, it is a classified landsat map which covers only some part ...
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76 views

Sediment transport index STI

To calculate the STI one applies the following formula in the raster calculator: Power(“FlowAccumulationArea_Raster”/22.13,0.6) * Power(Sin(“Slope_Raster”/0.0896),1.3) Now I have a problem which I ...
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52 views

Raster Calculator and Land Change with multiple classifications

I am looking at land cover data that is separated into three classes: upland, wetland, and open water. I have the data for varying years. I am interested in seeing how the land has changed over the ...
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2answers
232 views

NDVI from Landsat8 LandsatLook images

I have downloaded landsat image from this site and now Im wondering if i can get NDVI index from it. In raster calculator I have only 3 ranges, shouldnt be four? Or am I doing something ...
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1answer
129 views

Markov chains, cellular automata, and raster algebra

I need to build a probabilistic cellular automaton for simulating land-use changes and am wondering how to implement this in a GIS. I understand that Markov chains are a way of doing this, and IDRISI ...
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60 views

Con statement in raster calculator Arc GIS 10.3

I have four rasters (A, B, C, D) based on which my classification works. The con statement I have been using is posted below. My problem is when A_01 is 2. Area when A=2, if value of B is less than ...
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1answer
39 views

How to change value in raster layer?

I have created future temperature raster (tiff format) in ArcGIS. However I want all pixel's value to be multiply with 10 (constant value). I tried to use con tool and raster calculator in spatial ...
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52 views

Conditional statement in ArcGIS Raster Calculator?

I am new to Arcmap... I want to make a conditional statement in Raster calculator that checks if the pixel does not contain water or forest value ,, assign them snow as 1 and vice versa... Like the ...
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1answer
72 views

Calculating percentage of cells which are lower than site in Grass GIS?

In GRASS GIS: I have a shapefile with 300 hundred of sites (with height values for each point), and want to calculate the percentage or number of cells (of a given DEM) which are lower than the ...
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199 views

Adding all Binary Rasters in a Directory Using Raster Calculator in a Standalone Python Script

I have a directory with binary raster files (1 band only) which I need to add in a standalone python script. The problem is the rasters have different number of rows and columns and different ...
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29 views

Raster conditional tool unexpected results. What's wrong?

I have a DEM raster (High: 53441, Low: -3444, unit: cms) with negative values, and I want to make all values 100 or less to be 100. I've tried Raster Calculator, and also python. I've got the same ...
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37 views

Reclass a raster based off a percentage of the COUNT values using Con

I have a raster with a VALUE field and a COUNT field. I've sorted (descending) the VALUE field. Now I want to run a Con statement or a reclass to create a new raster based off the top 20% of the SUM ...
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1answer
43 views

How to replace raster values in one Raster with another [duplicate]

I have two raster files in ArcGIS 10.1, raster 1 and raster 2 all with values and similar spatial resolutions, and overlay in some areas. I want to replace values in raster 1 with those in raster 2 ...
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40 views

problem with raster calculator results when subtracting two rasters with different resolutions

I have two elevation datasets which I am trying to subtract to calculate thickness (using ArcGIS raster calculator). The first datset is a tif which is oriented north-south and has a cell size of 5 ft ...
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2answers
45 views

QGIS 2.8.6 raster calculator: cannot select cells which are below a value in a raster

I have a distance raster map in tif format and I am trying to generate a binary raster where cells below 200m are asigned value 1 and cells above that value are 0. I've converted the distance raster ...
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1answer
53 views

How to find the sum of many raster files in arcmap?

I have a list of 576 raster files for which I need to find the SUM. Obviously using raster calculator one by one would be tedious. Any easy script in Arcpy to do this?
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Looking for a raster calculator C# class

I am developing an application using C# and dotspatial. I need to performs raster calculation a lot..I need a library which helps me to do it..Do you know any library for this purpose? The library ...
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1answer
44 views

Addition of rasters using raster calculator

I have five classes of rivers as different rasters. and I want to add them all in a new raster file using raster calculator. But when I do this, it creates 16 types of classes, while I want am ...
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23 views

Recover failed raster calculator operation QGIS

Users can recover their raster calculator algorithms via the "results" panel in ArcMap (i.e., analogous to viewing one's "history"). Is there a similar function in QGIS? In other words, is there a ...
0
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1answer
44 views

How to prevent RGB composite flatten to 1 band after raster calculation

I have a series of landsat wanting to process in raster calculator, but after doing the tool it happened these output images only contain one single band. They used to be RGB 3-band images. It is on ...
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1answer
68 views

QGIS Zonal Stats Plugin - Python Console - compute one specific statistic

I think this is more of a syntax problem that I have here. But I am absolutely not able to figure it out. On a different Linux machine I got the following working: zoneStat = QgsZonalStatistics ...
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42 views

How do I change my “no data” values to get “true” values in raster calculator in Qgis

I have two rasters and I want to subtract the values from one of the layers. The first raster is a altitude raster and the second raster is depth values for a lake. I would like to subtract the depth ...
3
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1answer
37 views

QGIS Raster Calculator syntax

I have tried this several different ways and get lots of NaN. I need to specify that in my raster 'test1', I want a certain set of values to equal 1 and the rest to equal zero. For instance, I want ...
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1answer
110 views

Huge file size after averaging two rasters

After I average two raster files (singleband gray, initial size ~700MB each) through QgsRasterCalculator() with formula "Raster1@1/2 + Raster2@1/2" the size of the resulting file is 2.9GB. Is there ...
4
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1answer
38 views

ArcGIS merge/unite two rasters with same extent with RasterCalculator

I've a problem with the ArcGIS Raster Calculator: I have two 2-Bit Rasters with the same extent, the only data stored in it are 1-values and NoData. Now I want to combine this two Rasters: If in ...
3
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1answer
58 views

Convert 0's to NoData in QGIS Raster Calculator [duplicate]

What is the easiest way to convert cells with a value of 0 to NoData in QGIS Raster Calculator?
5
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1answer
91 views

Sequentially distilling several raster data sets into final map based on first time pixel’s value was greater than zero?

I have 120 daily data sets that contain a value only when a threshold temperature is exceeded. If the threshold has been reached that pixel was assigned a value indicating the day it occurred (the ...
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1answer
43 views

Changing raster value based on point feature

I am working on some landslide modeling. Within ArcMap I have a raster layer, representing the area of the county I am working in, and a point layer that shows landslide locations. I reclassified ...
5
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1answer
767 views

Raster Calculator making incorrect calculations in ArcGIS for Desktop?

I am trying to use raster calculator (ArcMap 10.2.2.3552) to apply a poisson generalized linear model to estimate species abundances based on elevation. The outputs don't make any sense to me, and I'm ...
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2answers
33 views

Polygon to raster. How to keep same values?

I have a polygon with values 3, 6, 9, 12, 15, 18, 21, 24, 27 an 30. These are the time it takes for the firetruck to reach certain destinations. Now i want to compare these to another raster that have ...
2
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2answers
58 views

I have slope raster and that is categorized with slope in percentage(%) but my script not successful

I have slope raster and that is categorized with slope in percentage(%) my condition is if slope <= 1 then m = 0.2 1 < slope <= 3 then m = ...
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1answer
626 views

Using Raster Calculator expression in Python

I've posted about this problem before but I've got a few new questions. So here's the problem. I have two rasters containing bathymetry data: one containing the bathymetry of the sea floor, we'll ...
2
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3answers
54 views

Add value to entire column in attributes

Is there a way to add a value to the entire column? I don't think i can use raster calculator because it's a text i want to add, the letter "B". Here is a picture. This is what happends when i use ...
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0answers
71 views

Using attribute table values as input for raster calculation - modelbuilder and iteration

I have multiple years of daily XY point shapefiles that contains multiple attributes. I would like to choose one attribute from my XY point and perform a raster calculation with that value and apply ...
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47 views

Performing Raster Algebra using DotSpatial?

I want to perform some Raster Algebra using DotSpatial. Is there any solution for it? Or any examples? this is a class which I am developing to perform raster algabra but as you see there is some ...
3
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1answer
62 views

Standardising DEM raster for a MCE

I'm trying to complete a Multi-Criteria Evaluation for an MSc assessment and am in the process of standardising my factor maps. Unfortunately, my DEM layer (ASCII file) keeps changing from this: ...
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1answer
35 views

Raster calculator iteration

I have a set of rasters within a file gdb in which are of continuous values (NDVI). I am trying to build an attribute table for each raster in order to reclassify into either 1 or 2 (water or land). I ...