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

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118 views

How can I smooth a discrete raster in ArcGIS?

I started with a continuous spline raster of hotspots, classified by standard deviations from the mean. This displays as 7 classes, but since it's a continuous raster in ArcGIS 10.2, it appears nice ...
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1answer
86 views

how to calculate the mean value of pixels of a raster in Grass plugin in qgis?

I am using grass plugin in qgis 2.12. I have to estimate the average value of all the pixels but don't know how to do it.
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49 views

raster calculator (spatial analyst) tool not working in arcpy [duplicate]

I am using arcpy and while running the script it is unable to find RasterCalculator() method? Even after imporiting arpy module >>> RasterCalculator("IDSI_2002.img + IDSI_2007.img","D:/...
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1answer
27 views

Combine two rasters- only value 1 stays; zeros converted to NoData cells

I am trying to combine 2 rasters: one with values = 1 and the other with values = 0 because I need a final raster with no empty cells. When I use the Raster calculator, the resulting raster only ...
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51 views

Raster calculators in SAGA return incorrect results

Here's a sample of my dataset (one cell) with 28 different raster values, representing 28 individual Float32 rasters with identical parameters. 0.0000264434, 0.0049953502, 0.0007529828, 0....
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91 views

QGIS raster calculator - crash minidump

I'm new to QGIS and using version 2.10.1-Pisa. I have two raster layers created from ASTER DEM data. I have one for slope and want to create a binary layer where only pixels between 8 and 60 degrees ...
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1answer
230 views

Conditional statement in gdal_calc with result as float, not boolean

Many examples on gis.se that refer to gdal_calc give a boolean example. example 1 example 2 If I need to calculate a conditional statement on a float: If Raster_Value >= 1024, then 1024; else ...
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58 views

Determining raster intersection using ArcGIS for Desktop?

Using Arc 10.2.2 with Spatial Analyst, I need to determine the spatial intersection of two rasters (both rasters are in the same coordinate system, and are aligned to the same snap raster). The two ...
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261 views

Flow Accumulation Python or MATLAB Script

does anyone have any resources for scripting the D8 flow accumulation in Python or MATLAB after obtaining the flow direction values and filling in 'sinks' and 'flats'? I am trying to understand the ...
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1answer
60 views

Raster processing in ArcPy seems to “simplify”/“round” my resulting values

I'm working off a DEM and doing some raster algebra with it (real simple, add this decimal value, then divide by this value). The DEM in question is super high resolution LiDAR, that's both spatially ...
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83 views

Calculating slope between 5 and 10 percent using raster calculator of QGIS?

I went to Raster --> Analysis --> DEM (Terrain Models) to compute slope. The slope ranges from 0-39.2311. Now I'm unsure of the correct way to calculate slope between 5-10% in the raster ...
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58 views

ArcGIS 10.1 SA Raster calculator: Multi-raster conditional with nodata

I have a question regarding the Con statement when used in the SA Raster Calculator. I am reclassifying a raster (categorical, integer) based on my own mappings but also on another raster (for some ...
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51 views

Using OR and ISNULL in Raster Calculator

I am using ModelBuilder for ArcGIS Desktop 10.2 I have the following code in the Raster Calcualtor which works in some cases but not in others. Int(Con(IsNull("%A%")|"%A%"== 0,"%B%",float(%Max%) + "%...
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1answer
44 views

Performing raster calculations along line feature or within polygon using QGIS?

I need to add a value to a dem file along a polyline feature or within a polygon. How can I add 100 to the values of the raster cells intersected by my line feature or within my polygon feature. I ...
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1answer
38 views

Mathematical functions in Arcmap's raster calculator - Derivatives & Complex numbers

Is it possible to calculate derivatives and complex numbers on rasters inside the raster calculator in Arcmap ? If not, is there any walkaround ? Also, QGIS or any other opensource software can ...
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1answer
78 views

Algorithm for soil texture calculation

Ok. I have percent sand/silt/clay values for 30 sample points on grid. I used these values to create 3 interpolated IDW rasters. I want to somehow (I think in raster calculator) to make a code using ...
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1answer
89 views

QGIS raster calculator error: cannot convert float infinity to integer

I just made a simple subtraction between two raster layers and got the error: Traceback (most recent call last): File "C:/Users/user/.qgis2/python/plugins\raster_transparency\...
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2answers
56 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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2answers
131 views

Expand raster nodata area (shrink values area)

I need to fix a raster that's been inappropriately resampled along the nodata edge. The bad data area is narrow, pretty much a single cell. The value range is too variable to use a simple "erase less ...
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1answer
65 views

Raster Calculator Parsing Error

I am using three cons with raster calculator to give four different results depending on the values within two rasters, aclip20151111 and sclip20151111. There are four results I want; RESULTA, RESULTB,...
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1answer
37 views

Where command in raster calculator Arcgis

I have two rasters that I wish to combine to give a third raster that describes spatially where multiple conditions of both rasters are met. For example, say my two input rasters are raster A and ...
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1answer
19 views

Assign values to raster in QGIS

I'm stack with a simple issue. I have a raster (DEM) and what I want to do is to assign -9999 where the pixel value of the DEM is 500 and leave all the other values as the original ones. I tried: (...
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23 views

Map algebra with raster [duplicate]

I am doing some map algebra with a raster however the result is not correct. I think it is because the cellsize (x,y) is in decimal degree (0,00027777778, 0,00027777778) and the z values are in meter. ...
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53 views

Adding Raster by raster calculator gives no values

I`m trying to add several raster files to one (like a merge). I tried using the raster calculator (in ArcGIS 10.2.2 and in QGIS 2.8.1 and QGIS 2.10). Anything I do leads to rasterfiles which have only ...
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1answer
25 views

How to fix a calculate value tool to work in a large model and skip featureless rasters?

I'm attempting to run a model that contains some rasters that do not have any features after being processed through my raster calculator. I have a calculate value tool from a previous question that ...
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31 views

Determining mathematical expression for Boolean logic with 5 raster layers in ArcGIS for Desktop? [closed]

I have 5 layers in ArcGIS 10.2 for Desktop, and i want to apply Boolean Logic. What will be the mathematical expression in "Raster Calculator". I know that for to layers expression will be like ("...
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1answer
124 views

Calculating the difference between two grids in percent with QGIS

I'm using the QGIS GDAL Raster Calculator to get the difference in percent between two grids. Grid A contains an integer, and grid B contains an integer which may be the same as or larger than the ...
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1answer
111 views

Calculate Volume over sloped ground in GRASS GIS

I am trying to do some volume calculations on a DEM with GRASS GIS. However, I believe r.volume measures everything from 0. The ground underneath the pile I'm measuring is sloped. I would ...
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28 views

Map Algebra with Zero-inflated regression weights

I have a non-normal count variable y and 6 rasters x1 to x6, each mapped onto a (n x n) grid. I have applied a zero-inflated negative binomial regression using the pscl package of R. I now need to ...
2
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1answer
531 views

Raster Calculator in QGIS returning 'nan' values

I am attempting to add two rasters using the QGIS raster calculator and every output ends up as 'nan'. There were no problems with the raster calculator before trying to add these rasters, so I am ...
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3answers
159 views

Raster calculator : How to make 0 + NoData = 0?

I have a point data layer (vector) that I converted to a raster layer. I want to replace the NoData value (between each raster point) in the point raster layer by 0. So, I made a background raster ...
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201 views

DEM Processing in ArcMap

I have a question regarding DEM. I have downloaded SRTM DEM 30 m and I did a mosaic for the data using Mosaic tools in Arcmap to a Mosaic to a new raster. However, I got a DEM raster with values of 0-...
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77 views

Can I run hydrology tools within focal statistics?

I've been trying to identify ridges and valleys from a DEM and have been using hydrology tools. I identify rivers as areas that have a value on an accumulation raster above a threshold, then valleys ...
2
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1answer
99 views

Iterate - Raster Calculator - 8 Day MODIS LST to Monthly Avg

I have 8-day MODIS Land Surface Temperature data from 2009-2013. I have used Model Builder to extract the LST_day and LST_Night Subdatasets (in different model runs). What I am attempting to do next ...
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1answer
59 views

Adding multiple rasters produces unexpected results. I have set the data extent to the same in all rasters

I am trying to add three rasters together. I'm trying to figure out where I am going wrong so I am going to list out what I am doing: I have Raster_1, Raster_2 and Raster_3. Raster_1 and Raster_2 ...
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1answer
68 views

How to combine bands from different rasters using the global mapper raster calculator?

I am wondering how to specify what raster you are getting the band from in the global mapper raster calculator? When you open it with a more then one raster open you can check the boxes to define ...
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3answers
87 views

Making raster output based on comparison between 2 input rasters using ArcGIS for Desktop?

I have 2 input rasters of rainfall for summer/winter and I want to make a 3rd output based on which one has the max value for that cell. So if the max value at the cell is summer it will assign 1, or ...
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3answers
341 views

Adding two raster datasets that overlap while maintaining extent of larger raster dataset?

I am using ArcMAP 10.0 How do I add two raster datasets that overlap while maintaining the extent of the larger raster dataset. I have thought of adding zero values to the smaller raster to then be ...
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101 views

Kernel Density Estimation Crimestat

I calculated a series of Kernel Density Estimations in CrimeStat (because more parameters can be set than in the built-in tool in ArcGIS) and then imported the results into ArcMap. I wanted to combine ...
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1answer
84 views

Parsing error : invalid syntax (line 1) from ArcGIS Raster Calculator?

I have a (Aspect)raster (32bit, floating point,overall 2.9GB) of a landscape and need to devide it with π/180, in order to get the mean aspect later. My raster calculator (Spatial Analyst --> Map ...
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105 views

Adding rasters with GeoTools

I'm using org.geotools.process.raster.AddCoveragesProcess class, to add two raster's with same resolution and buonding box. I get the following exception java.lang.IllegalArgumentException: Range ...
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2answers
63 views

How can I stop my map algebra being limited to the size of my smallest raster?

I have five input rasters and I'm using map algebra to find areas where all of them have a value over 75, areas where all of them are over 25, and areas where one or more are under 25. I can do this ...
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1answer
355 views

Using Loop with Raster Calculator in ArcPy?

I am trying to loop through multiple rasters and extract cells that are above 0.1 The code I am trying to use is: import arcpy arcpy.CheckOutExtension('Spatial') arcpy.env.workspace=r'F:\Sheyenne\...
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1answer
128 views

How can I add a Raster Calculator tool on QGIS Processing Modeler?

I'm trying to add the Raster Calculator to a model I'm creating using the Processing Modeler of QGIS 2.6 Brighton. It does not allow me to add the normal Raster Calculator tool under Raster, so I ...
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1answer
430 views

Raster Calculator Iteration in ModelBuilder?

I have a large number of rasters and I want to add 1 to each of them (e.g. each raster's values currently range from 0 to 1, and I want to make them range from 1 to 2). I believe ModelBuilder, using ...
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1answer
49 views

Can I multiply fractions in map algebra?

I have a couple of rasters that show % of success in different things. I want to calculate the overall probability of success. The numerical values are integers so they represent the percentage. This ...
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1answer
151 views

How to reclassify raster data that falls within a polygon

Thansk for your response Okay so I will reword my question more clearly I'm currently using ArcGIS 10. My task is to map forest cover with the image classification tool. The problem is some of the ...
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72 views

How can I replicate focalmean with focal statistics

Hi I am trying to get rid of some small gaps of no data in my rasters. I would previosly have used focalmean but it is no longer available. I've tried what I expected to work but I'm getting errors. ...
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1answer
51 views

count band numbers from multiband raster image

My raster image has 10 bands (10 bands are 10 year), cell values of each one are 1, 2, 3. One is negative anomaly, 2 is no change area, 3 is positive anomaly. Now I want to find how many years out of ...
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54 views

how I can get raster calculator select files with similar names?

The idea is to select raster files with parts of similar name, for example: Filenames (in between many others raster with other names, but in the same folder): 28feb11evs 28feb11evv 28feb11pr ...