Questions tagged [raster-calculator]
A tool in some GIS software programs for performing algebraic operations on rasters.
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1answer
53 views
How can I translate the WGS 84 datum to mean sea level?
I'm very new to GIS so here my question is I have WGS84 DEM data for my country and I want to calculate the sea level rise. I will use QGIS raster calculator, my problem is I need to find sea level ...
1
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1answer
25 views
Adding two rasters in modeller
I'm trying to build a process model which uses a series of raster operations - Rasterize, Proximity, Raster Calculator. However, I couldn't seem to add two consecutive raster calculator processes.
...
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0answers
14 views
Understanding Raster Calculator Error 000539?
I tried to convert a float raster into polygons follwing the manual of Esri support (https://support.esri.com/en/technical-article/000012554). In the first step it says that you need to multiply your ...
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1answer
26 views
Buffer zone, binary exclusion
I have a shapefile of 20 cities in ArcMap 10.
I need to position a sheep farm so that it is not within 2 miles of any of these cities.
So, I created a buffer, with 2 miles as distance.
I used the ...
0
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1answer
27 views
Reclassify with attribute
So, I don't really know how to word what I want to ask, but I took a DEM file and did used the raster calculator to select a certain elevation range. After that I reclassified it to separate it into ...
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1answer
25 views
QGIS raster calculator is not keeping each pixel with 1 byte
I have a raster where 1 pixel = 1 byte. I want to change every value different than zero to 1, transforming a gray scale into black & white. I think the expression should be:
"my_raster@1" > 0
...
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2answers
87 views
Replacing data in raster using condition?
I have a raster dataset in ArcGIS displaying altitude.
I want to replace all values < 8 with value 8.
Other values have to stay the same. How can I do this?
I tried raster calculator, but I don'...
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0answers
34 views
Using QGIS raster calculator for expression of height with RGB?
I'm using QGIS 3.4.1, and downloaded the SRTM TIFF data for the area of my interest, and added the TIFF format SRTM file to my project as a raster layer.
Here, I wish to make my own color gradient ...
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1answer
45 views
Improving QGIS raster calculation performance?
I'm performing raster analysis on a QGIS 2.14 project CRS is EPSG: 32632.
I used the official 10m DEM supplied by local authorities of Sardinia extracting the area of interest of 446 raster cells.
I'...
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2answers
77 views
Error 000539 running multiple con expressions in raster calculator in ModelBuilder?
I am using Raster Calcuator in ModelBuilder with ArcMap 10.5.
I used Get Raster Properties to extract Standard Deviation and Mean from a previously calculated raster.
I would like to use Raster ...
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1answer
25 views
Extracting a single value to a new raster from a singleband pseudocolor raster image
I have a large raster image depicting land use. It's a singleband pseudocolor image whose values are contained in a text file. There are 5 classes.
Following the example of this question I thought I ...
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1answer
32 views
Error 000539 Error Running Expression
I am receiving Error 000539 while running raster calculator in the model builder. I have read on other forums that this is a problem with using python script but I have been using the dialog boxes in ...
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1answer
24 views
Calculating average raster from two other rasters using Raster Calculator?
I have to calculate an average raster from 4 rasters. I have tried in ArcMap with Raster Calculator but the result is wrong. It's a line. I'm sure that I've done something wrong, but I don't know what....
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3answers
58 views
Working with 2 rasters, having different extents but same resolution, in ArcGIS raster calculator?
I am working with 2 rasters, having different extents but same coordinate system and resolution, in Arcgis 10.5. The larger raster has 0 and smaller raster has 1 values. I want to make a new raster ...
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0answers
47 views
Why is Raster Calculator not honoring compression environment settings?
For some reason, the Raster Calculator isn't honoring any Raster Storage environments that I have set. Mainly, compression and pyramids. I am processing a large raster dataset through raster ...
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1answer
111 views
ArcPy Raster Calculator error “ 'str' object has no attribute 'save' ”
I converted a model into python script and tried to run it. It gave me an error when it gets to the raster calculator process.The message says "str" object has no attribute "save". See picture below.
...
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0answers
25 views
Creating quarterly rasters from monthly rasters for multiple years with ArcPy? [closed]
I'm attempting to create quarterly rasters from monthly PRISM .bil files that I've already masked to my ROI. Essentially I'm trying to automate the process of using Raster Calculator to add 3 monthly ...
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1answer
69 views
QGIS raster calculator gives 'Nan'
With QGIS 2.14.3 I am attempting to convert a raster layer to a binary layer, using a certain threshold. With some layers I can use this formula in the Raster Calculator and get the expected output;
"...
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0answers
17 views
Accuracy/Precision of Zonal Statistics as Table tool ArcGIS Pro
I have a raster image whereby I used Raster Calculator to proportion new raster values into the pixels. Here's what I did:
Obtained sum of all pixels using Zonal Statistics as Table tool. I used the '...
2
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0answers
60 views
Calculating indices such as NDVI or NDSI on Landsat 8 imagery whose pixel type is 16 bit signed integer?
I am trying to calculate an NDSI (Normalized Difference Snow Index) using Landsat 8 OLI level 1 imagery atmospherically corrected in ERDAS ATCOR using raster calculator in ArcMap. NDSI is used to to ...
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0answers
33 views
Expanding raster to fill bounding polygon using ArcGIS Desktop?
I work for an agronomy company that utilizes an EC scanner (electric conductivity) to gather point data within fields. Due to terrain constraints there are often out edges of the fields where no data ...
2
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2answers
50 views
Reclassifying certain values using ArcPy in ArcGIS Pro?
I need to reclassify certain values to different values in a raster using Python in ArcGIS Pro 2.2.2. I can't use reclassify because I don't want to change all values and I can't go through each one ...
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1answer
20 views
Changing values of slope along polyline to 0 using ArcGIS Spatial Analyst?
In ArcGIS 10.1 (advanced license), I have a slope raster of a given area and a polyline.
I want to set the slope values along the polyline to 0.
I'm thinking of this process - extract the cells ...
0
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1answer
70 views
Select % of pixel that have a specific value in R
I have a the following raster layer
class : RasterLayer
dimensions : 3865, 6899, 26664635 (nrow, ncol, ncell)
resolution : 14.83, 14.83 (x, y)
extent : 361363.5, 463675.7, 5760647, ...
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0answers
31 views
Identify bands for calculated indexes when you have a raster with 4 bands in QGIS
I want to calculate a few indexes but when I merge the bands, they separate in @1,@2,@3 and @4. How can I know which of these are the green, red, red edge and NIR ones?
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2answers
294 views
Calculate pixel value in arcmap
I want to change pixel values of elevation data. I want to change values meter to feet. So i need to multiply pixel values with 3.2808. How can i do that in arcmap?
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1answer
41 views
How calculate vegetation indexes with GDAL raster calculator
I want to calculate a few of vegetation indexes [ example: NDPI (red band-green band)/(red band + green band)] in a model with the GDAL raster calculator but I don't know how put the equation here:
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0answers
35 views
Raster value range changes while replacing values with NA
I'm fairly new in working with R (due to the huge amount of data), but here is the deal. I'm working on a large dataset of raster images (surface reflectance bands of a time series of Landsat scenes). ...
0
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1answer
21 views
Max value for each cell
I am using ArcMap. I have 12 raster layers with coincident pixels, which have different values. I would like to, for each pixel location, pick the pixel from all 12 rasters which have the same value.
...
-1
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1answer
54 views
Use of model and some tools from QGIS
(repost)
This is what I want to do...
Data:
-raster images with 4 bands (green,red,red-edge and NIR),there are like 30 folders with one zone per folder and the images where taken 3 periods of time.
...
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0answers
26 views
Use raster calculator on an Image Service in ArcMap or ArcGIS Pro
I'm mapping the approximate polygon shapes of dirt roads in a large area.
I can see the roads clearly on the world imagery basemap and on the USA NAIP image service.
Can I use Raster Calculator to ...
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1answer
56 views
Get a raster composed of 0s and 1s
Novice with ArcGis, I would like to convert my Polyline dataset to a Raster with only 0s and 1s
To this end, I used the Gis command "Polyline to Raster" and set the cell size small enough, so that ...
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1answer
23 views
Raster Symbology Calculate Area Acres
Using ArcMap, I am trying to classify/consolidate the symbology of these agriculture classes into 3 categories: Hay, Pasture/Grass, and Cropland. I also need to find the sum of acres of each of these ...
2
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1answer
38 views
Computing NDVI in ArcMap from Landsat 8 “Analysis-Ready” Surface and TOA Reflectance Products
The internet is full of various contradictory advice on corrections one can make to get NDVI computed from Landsat 8 to fall between -1 and 1.
This is for instructional purposes, so I hope to use ...
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37 views
how to calculate the percentage of raster value of each singular buffer?
I am having a problem calculating the percentage of certain raster values inside buffers.
I have 1 raster layer with pixel values and 1 vector layer with 40 points.
The 40 points are people living in ...
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1answer
23 views
Resize rasters to add empty data around edges
I have a set of DEMs that have different extents due to different data being available at each of the sample points these DEMs were generated from. I need to use these to create a set of uniformly ...
1
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1answer
31 views
Building multiple CON statements with OR/AND in ArcGIS Raster Calculator?
I have two raster "T" and "N" which have values ranging from 0 to 1000. This is the logic that I want to query and create the new raster:
This is how I tried to query in a syntax-correct way in the ...
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0answers
18 views
Generate NULL rastercells
I do have some big rasterdata (7100 lines, 7500 columns - bigger then 200 MB). It contains information in 1 (relevant) and 0 (not relevant).
I like to cut all cells which contain 1 out of some vector ...
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1answer
57 views
Converting Kelvin to Celsius in PyQgis
from qgis.analysis import QgsRasterCalculator, QgsRasterCalculatorEntry
raster = '/home/francis/QGIS/epelwrf/temp/temp0000-postwrf_d01_20180720_0600_f00000.gr2'
bohLayer = QgsRasterLayer(raster)
...
0
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1answer
31 views
Extracting raster values and creating new raster in QGIS is not working as intended
I am trying to extract certain values from a raster image in order to create a new raster which should then only contain the specified values. I have a single band raster showing forest loss from 2000 ...
1
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2answers
46 views
Clip raster by polygon, reassign values of clipped raster, merged reassigned raster with original
I'm trying to clip out part of a raster (DEM), change the values within the clipped raster and then merge/join the edited raster back into the original. The context is that I have a high resolution ...
1
vote
2answers
141 views
Batch Calculating Indices
I have 111 Landsat8 scenes which I want to calculate several indices for.
The algebra to calculate them is most of the time Index= (b1-b2)/(b1+b2).
I have the single bands (bands 1-11 respectively) ...
0
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1answer
21 views
Reducing height through ArcGIS raster calculator?
I am using ArcMap 10.4.1
I have a DTM (10x10)m, and a raster (rasterized from polygon) that I want to subtract the DTM with.
In the picture below, four areas have different values I want to reduce ...
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0answers
46 views
How can I merge a DEM mosaic with an overlapping bathymetry raster (while keeping only the portions of each that I want)?
I am tasked with merging a bathymetry raster with a mosaic raster I created from ArcGrid DEM Tiles downloaded from the National Map, for an areal extent spanning the Coastal Lowlands Aquifer System.
...
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0answers
26 views
Selecting pixels in raster using polygon selection tool in QGIS?
I want to reclassify landcover image manually with respect to online imagery. I am looking for a software/plugin/script to manually select raster pixels using polygon selection tool and could be able ...
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0answers
23 views
Error 999999 when using minus tool to extract elevation difference between two rasters
I have two raster DEMs in tif format. They both have the same cell size and spatial reference. I want to subtract the elevation from the 2nd picture from that of the same area in the 1st picture. When ...
0
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1answer
22 views
Divide all values in ASCII table (or raster file)
I have a pile of ASCII files representing 5min radar precipitation sums. The information is given in 1/10 mm which I need to convert into mm for further processing.
Is there a way of doing this, ...
0
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1answer
27 views
Seeking alternative to deprecated Min in Raster Calculator?
I've been trying to run an old model built on 9.3 within 10.6 and I've run into the following error:
NameError: name 'Min' is not defined
I believe the Min function was removed after 10.0 (?) but ...
2
votes
2answers
43 views
Applying Map Algebra to List of Rasters and Saving New File in New Directory?
I am trying to multiply each raster by coefficient using Map Algebra in Python. I receive the following error for the code below:
calcRaster.save(calcRasterName) AttributeError: 'unicode' object ...
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1answer
67 views
Elevation shading of linear feature compared to surrounding ground level in QGIS
I have a digital elevation model (DEM - geoTIFF) in QGIS 3.2. There is a linear feature (earth bund/wall) in the DEM that I would like to shade/colour based on its elevation above the surrounding ...
