Questions tagged [raster-calculator]
A tool in some GIS software programs for performing algebraic operations on rasters.
813
questions
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0answers
18 views
Strange output while calculating raster in QGIS
I've encountered the following problem frequently when I am using the raster calculator, even though sometimes the calculator works. However, I cannot figure out the difference between the times it ...
2
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0answers
23 views
Multiple conditional statements for raster calculation in R
In the context of a RUSLE erosion modelling I would like to calculate the sum of precipitation at the entry date of phenological phases.
Suppose I have 13 grids, one of which is the phenophase entry ...
0
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0answers
23 views
Calculating total cost along multiple polylines using ArcGIS Desktop?
I'm looking to create a new sewer line. Part of the process includes making a cost analysis, which mainly centers along elevation. Areas that are lower than the treatment area need to be pumped, areas ...
1
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1answer
31 views
ArcPy: Create NDVI with Raster Calculation and Map Algebra
My target is to create NDVI Rasters but I'm stuck with python loops, since I'm new to that, so sorry for a maybe basic question.
I have 2 folders, one with rasters (tif) with the red band, the other ...
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0answers
28 views
Creating raster from grid algebra expression using point attribute values?
I have a point shapefile representing groundwater production wells with annual pumpage values distributed over a general area. I'd like to create a raster layer with each cell representing the ...
1
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0answers
15 views
Raster Calculator in the Graphical Modeler of QGIS 2.18
How to convert this expression from raster calculator
("noise_heatmap_clip@1" <= 50) * 5 +
("noise_heatmap_clip@1" > 50 AND "noise_heatmap_clip@1" <= 100) * 4 +
("noise_heatmap_clip@1" > ...
0
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1answer
31 views
Find intersecting cell values for multiple rasters
I am trying to find where 2 raster cells values intersect. I have a ground DEM raster and a water elevation raster. I need to find where are values meeting and export the cells. In the graphic below,...
1
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1answer
21 views
Using Multiple Raster Intermediate Inputs in Raster Calculator within QGIS Process Modeler
I am stringing together a series of raster calculations in the QGIS process modeler in order to calculate a surface temperature dataset from Landsat and weather data.
When I use the output from ...
0
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1answer
20 views
Expanding raster with many zone values using ArcMap?
I am using ArcMap 10.6.1 and I need to expand a large raster with tens of thousands of zones by 1 cell using either the expand tool or a map algebra expression. The tool asks to specify each zone to ...
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0answers
23 views
Changing NODATA value GeoTIFF with ArcPy of ArcGIS Pro?
I'm using a tool in ArcPy for Python 3 (ArcGIS Pro) which applies an operation to a raster file in GeoTIFF format.
condicion = '("{}" - {}) / {}'.format(input_image,n,m)
arcpy.gp.RasterCalculator_sa(...
1
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1answer
53 views
Raster calculator - problems with syntax
I have a raster layer with values ranging from 0.00597303 to 0.102894 and I want to assign specific number representing a group to specific range of values:
Group 4: x >= 0.1
Group 3: 0.01 <= x ...
1
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0answers
29 views
Getting ERROR 000539 running Raster Calculator in ModelBuilder?
I am trying to run Raster Calculator in ModelBuilder, however I am getting what looks like two errors after my model reaches a certain step:
ERROR 000539: Error running
I'm not sure if it is a ...
1
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0answers
38 views
Raster statistic
i'm try to use QGIS processing modeler but I've a problem.
I need to use the Mean value and the standard deviation in raster calculator algorithm. I've calculated it in raster statistics, how can I do ...
1
vote
0answers
26 views
Calculating NDVI values for specific zones using zonal statistics using QGIS
I am currently working with multispectral data from a MicaSense RedEdge M on a plot size study in wheat research plots. I want to conduct zonal statistics to calculate NDVI for individual plots.
I ...
1
vote
1answer
54 views
Raster calculator issue in QGIS 3.8 and 3.8.1
I am trying to perform a simple raster calculation on an elevation layer to occlude certain values. I have used the following expression:
( ( "clipped_elev@1">500) AND ("clipped_elev@1"<1000))*"...
0
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0answers
10 views
Rescaling NDVI from 0-255 to -1-1 in ArcGIS Pro?
My NDVI raster ranges from 0-255. My goal is to get values from -1 to 1.
If using the Raster Calculator, what would be the correct equation to achieve this?
I'm working in ArcGIS Pro.
0
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1answer
17 views
Give non-overlapping parts of 2 rasters a value 0 (QGIS)
Is there a way in QGIS to give non-overlapping parts of 2 rasters a value of 0 in the new raster file?
I would like the data gaps in the velocity file (so where Ice mask is displayed on the chart) ...
1
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1answer
29 views
Tweak raster calculation
I’m creating layers with qgis 3.4 raster calculator. How can I go back and modify the calcs or do I have to start over every time?
0
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1answer
32 views
Finding overlap and sum of rasters using ArcGIS ModelBuilder?
I have about 300 rasters that I need to find the overlap and sum of to find 'hotspots'. I set each raster value to 1 and used the Mosaic to New Raster tool to create a new raster. I tested this with ...
1
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0answers
33 views
All 0s result from raster calculator in python
Raster calculator is not working correctly for a single calculation using a standalone Python script. I am trying to add 1 to a pre-existing raster. It processes, but the resulting tiff file is all 0s....
0
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1answer
28 views
ArcMap Raster Calculator SetNull not changing value?
I am having issues with the "SetNull" function within the Raster Calculator in ArcMap. I have a landsat 8 image that I separated the bands into their own raster (only working with 6 of them), bands 2-...
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0answers
21 views
Join DEM and GPS data point ArcMap
I have a problem using ArcGIS. I have generate a DEM raster with a 3D online software and exported it in ArcGIS. So I have a raster of my surface. After that, I have some GPS point (x,y,z) that we ...
1
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1answer
36 views
Setting RGB TIFF “zero” values to “NoData”
I am having a problem with getting my Landsat 8 RGB (bands 2-7) .tif background values (very small number but not zero) set to null. I have tried the following tools:
Raster Calculator (image 2)
...
1
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0answers
16 views
Calculating the distance of raster cells from a vector within a polygon using QGIS
I am quite new to QGIS and am trying to use QGIS 3.6 to create a raster layer of calculated values of the minimum distance of each cells within a polygon (orange) from a vector (the river channel in ...
4
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1answer
62 views
Using variable in graphical modeler for raster calculation? (QGIS 3.8)
I am trying to create a flow in the graphical modeler using a variable in a raster calculation. Is there a way to use a variable directly in the raster calculator (SAGA or GDAL)? I know there was a ...
0
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2answers
21 views
Getting error 000539 when calculating TWI?
I'm trying to calculate the twi from my area using LN((flowaccu+1)*900/Tan(sloperadian). My first result was wrong because my area is an endhoreic basin. So I made a flow accumulation raster based on ...
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0answers
25 views
Raster calculator giving different results in ArcPy than in ArcGIS?
I have two rasters representing travelling speed: one for road (with speed values for different types of roads and "0" values where there is no roads) and one for land-cover (with lower values, but no ...
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0answers
16 views
Raster calculator and Zonal Statistics as a table do not work on joint combined raster?
I combined 3 raster files in ArcMap 10.4 and then joined 3 .dbf table to the combined raster and exported the result to a new .tif file.
Now I am trying to run "Raster calculator" and "Zonal ...
0
votes
0answers
16 views
Inverse values in raster heightmap
I have just converted a point vector into a tif using Rasterize in QGIS. And values are currently:
How do I completely flip the values as it should be Min -98.95 and Max 2.3
I can't find much when ...
2
votes
1answer
31 views
Using ArcGIS ModelBuilder iterator to for Raster Calculator?
I have a raster that I need to divide by X in a model. I have hundreds of values I need to divide it by. What I am trying to do is create a list of values, and use the iterator to loop through them ...
0
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1answer
33 views
Raster Calculator giving inccorect results with large numbers
I am attempting to multiply my raster values by 10000 using the raster calculator in QGIS 3.6.2. But am getting weird results. For example I have an initial raster value of 30303 and would expect a ...
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0answers
25 views
Reprojected raster return only zeros from QGIS raster calculator
I am experiencing an issue when trying to use my reprojected raster in QGIS raster calculator; First, my raster is reprojected from degrees to meters. After that, I want to process the layer by ...
0
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0answers
30 views
Using Raster Calculater to create .asc files in QGIS?
I have been trying to create an .asc file that contains the difference between two others. This can be represented as C=A-B. All files have the same size.
When using the Raster Calculator built into ...
1
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0answers
32 views
How to use the Raster Calculator in PyQGIS (Console) in QGIS 3?
I want to use a script to do some raster calculations. I found this and this posts which seem to answer this question, however, it seems that they work for QGIS 2 and not for QGIS 3. I think the ...
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0answers
16 views
Intersect multiple binary rasters based on certain criteria in ArcMap
I have multiple binary raster image (0.1). For example if I have n images, how can I extract the pixels that has the value of 1 and frequently occurred " the same pixels" in 70% of the n images (for ...
0
votes
1answer
44 views
GDAL Calc Set Specific Values to Another Number
I have a GeoTiff raster with a format of Float32 and values 0.00 to 5.00. I am attempting to change all raster cells with a value below 0.10 to 0.10, and leave all other cells in the raster dataset ...
1
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1answer
38 views
PyQGIS problem with QgsRasterCalculator CRS definition
from qgis.analysis import QgsRasterCalculator, QgsRasterCalculatorEntry import processing
from osgeo import osr, gdal from gdalconst import *
dataset1 = gdal.Open(input1, GA_Update) band1 = dataset1....
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2answers
61 views
QGIS - raster calculator syntax
I am having problems using the raster calculator. Some pixels of my GeoTIFF file have the value 255 on bands 1, 2 and 3. I want to replace this value with 0 on the three bands.
I tried with this ...
2
votes
1answer
31 views
Sum multiple rasters using raster calculator, the result raster had a larger cell size?
I have 365 rasters (daily) and therefore I summed them to form an annual raster using raster calculator in Arcgis. The original cell size of daily raster is 5*3.75 (col 72, row 48), while the cell ...
1
vote
1answer
54 views
QGIS 3.6.2 with GRASS - raster calculator - Raster1 + Raster2 returns missing pixels
I have 5 large point datasets (shapefiles) and I'm interested in getting a heatmap on the combination of all 5 point layers.
I use the QGIS heatmap tool to create a heatmap on each layer. This is ...
2
votes
1answer
40 views
Replace the empty cells of one raster with the values of a second raster
I have 2 rasters with the same extent. In the first raster, there are a lot of empty cells that I want to replace by the values of the second raster.
I have tried Raster calculation with the following ...
0
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0answers
20 views
Losing raster quality when using raster calculator (ArcGIS Desktop 10.5.1)
I'm currently working with DEM rasters that I hillshaded. The data I received contain nodata borders, probably the footprint of the originial mosaic dataset. As I received them separately, I can't ...
1
vote
1answer
65 views
Using ArcGIS Pro raster calculator to give cell value based on cells in its neighborhood?
I have a land cover dataset, I want to find forested cells that are adjacent (touch) agricultural cells.
Is there a way I can achieve this with the ArcGIS Pro raster calculator?
0
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1answer
37 views
Switching Mars DEM elevation values from negative to positive?
I'm using a DEM of Mars I got from UA's HiRISE website, and I want to convert it into an STL for 3D printing using the DEMto3D plugin.
However, the raster values are all negative, so I thought I ...
2
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0answers
35 views
Writing Raster Calculator Expression?
I use ArcMap 10.3.
How do I create an expression in RasterCalculator that allows me to sum up 4 rasters (every pixel has an associated value) and the result to be 0 if any of the 4 values is 0?
For ...
0
votes
1answer
27 views
Creating new raster with minimum (or maximum) value betwen two rasters in ArcMap?
I am using ArcMap 10.3.
I have two temperature rasters from two months. I need to create a new raster from these, but the new raster should have in each cell the maximun value betwen the initial ...
2
votes
1answer
33 views
Raster calculator - set default output path - QGIS 3.4.6
Raster calculator: How can I set the default output folder?
By default it's set to "C:\Program Files\QGIS 3.4\bin"
I'm using QGIS 3.4.6
2
votes
0answers
39 views
Confusing result of raster calculator in QGIS
I'm confused about the results that I get from the raster calculator in QGIS.
I'm trying to delete the cells of a raster who are prone to flooding. However, a part of my raster is wrongly classified ...
1
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0answers
12 views
Discrepancy between raster calculator and geomorphic change detection elevation change results
I am using two rasters to determine the elevation change in a stream channel.
When I used the Geomorphic Change Detection Software add-in (version 7.4.1), I got a high elevation change of 8.8 ft and ...
2
votes
1answer
62 views
Counting .tif value in polygon in QGIS
I am trying to count raster values (from a .tif file) in polygons. In previous posts that people suggested using the 'zonal statistics' plugin in QGIS. However, I couldn't find it in my plugin manager ...
