Questions tagged [inverse-distance-weighted]

Inverse Distance Weighting (IDW) is a method of interpolation.

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Using ArcGIS Getis Ord Gi* and IDW tools with “hotspots” where unmeasured areas are “coldspots”?

I have two datasets that I would like to analyze together. The first dataset has bird nest locations in neighborhoods (nest). The second dataset has bird feeder locations in neighborhoods (food). At ...
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QGIS: IDW interpolation doesn't work?

Beginner user of QGIS: I used the tool called IDW Interpolation from QGIS. In the picture below you can see how I did it, with vector points imported from a CSV file. However the OUTPUT is completely ...
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215 views

IDW/Kriging running slow in R

I have a dataset with 2157335 entries, and I am performing IDW/Kriging to interpolate. But the code is running very slow. I am not sure this is because of a large dataset or there is something wrong ...
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Performing IDW interpolation with an output weighted by a different variable

I'm relatively new to spatial analysis. I'm trying to create an IDW map for SPI. However, I'm "correcting" the SPI so it gives a different value based on elevation. For example: Point A on the map ...
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AERSURFACE - How to calculate the inverse distance weighted geometric mean of surface caracteristics

I need to calculate the inverse distance weighted geometric mean of the cell values of different sectors within the 1-km radius from a weather station, using QGIS. I'll try to make it clearly below ...
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QGis GDAL Grid Inverse Distance to a power - Grid Size

When I run this function from QGis on a point shapefile, there is no option to determine the grid pixel size / resolution or dimensions. Am I missing something here?
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316 views

Kriging method vs. IDW in soil moisture interpolation

I have XY coordinates and soil moisture values for a grid of 10m and I used add XY data to import my excel data to ArcMap 10.5. I applied both IDW and kriging methods for interpolation. The results ...
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27 views

IDW Interpolation in QGIS 3.10 - Power Coefficient not working

Trying to set the power coefficient for the IDW interpolation in QGIS 3.10 in pyqgis. Whatever number I set it has no effect on the interpolation output - always the same output. The default is 2 ...
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Skip intermediate raster creation in interpolation model

I am interpolating values at specific coordinates. I am starting with point data and am using ModelBuilder so I can generate interpolated values for each day. The model (1) iterates through each row (...
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26 views

Using IDW in ArcPy script gives ERROR 000824

Using ArcMap 10.4 and Python 2. On ArcMap, I have the 3D Analyst and Spatial Analyst extensions checked out. I manually ran the IDW tool on a points feature class, and I was successfully able to ...
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95 views

Performing IDW for multiple Z field from attribute using ArcPy?

I have data with multiple columns as 1996_1, 1997_1, etc. I need to perform IDW for each column values and save it. I am a beginner with arcpy. Please help! The code is as follows: import arcpy, os ...
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Can non-elevation data be displayed in 3D? Such as EC measurements in soil over a surface?

I tried creating a tin in ArcScene with a raster I have from an IDW file of salinity at sample points in a field, but I can't get it to display as anything other than flat. My points range from ~1-40 ...
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120 views

Interpolation for unevenly spaced data points

I am currently having some trouble finding a good interpolation technique for unevenly distributed spatial data points. Let's give a quick example : I have a 1000 points dataset. As several surveys ...
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71 views

ArcGIS IDW interpolation elongated?

I am trying to do a very simple interpolation with soil nitrate data. I wanted to do IDW because points close to each other should be most similar. I used the IDW interpolation function in ArcMap (...
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30 views

Splitting polygon by sections obtained from IDW interpolation

I used IDW to show the rainfall pattern over a region ... the attached picture show the result ... my area split into three ranges that show 3 different colors... How can I split one original polygon ...
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Geochemical maps with QGIS: Case of multiple analyses in a point [closed]

I am a newbie, using QGIS 3.4. My goal is to create geochemical maps of species distribution in water samples. I mine data from a database, regarding specific points, which are boreholes or springs. ...
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IDW succeeded but not visible in table of contents

I used now several times ArcMap 10.7.1 and until now everything worked quite well. For my Masters Thesis I have to work with IDW to interpolate my datas. It worked all the time. Now, I run the IDW ...
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39 views

Using IDW tool in ArcGIS Desktop

In ArcGIS Desktop 10.7 we have IDW tool, but when you want to work with it you should need two layers such as : Some points and a closed polyline (Boundary) as following: then using IDW: but I have ...
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IDW of Points Converted from Rasters giving error message IDW [000000_12301899]

I've been attempting to create a DEM for a larger area from the available DEMs of a smaller area (portions of the larger area). I converted the DEMs to points and then merged then to one file so that ...
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42 views

Evaluating elevation change between multiple LiDAR datasets

I am hoping to get some insight from others who are familiar with comparing multiple LiDAR surveys to one another. I have two LiDAR surveys with similar extents that I would like compare for elevation ...
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34 views

For-loop to call fields for IDW-Interpolation

probably a question easy to answer, but I do not figure it out at the moment. I'm using station-data and do a IDW-interpolation to get average climate values in layer. The station's data is arranged ...
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1answer
35 views

Add legend with ArcPy over my interpolated map

I have created an interpolated map with arcpy.IDW_ga and I am exporting it to PDF with arcpy.mapping.ExportToPDF. How can I add a legend to the map with ArcPy? In the end, I want to apply the code to ...
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2answers
575 views

QGIS 3.x contour creation tutorial

I'm trying to follow this tutorial so I have a method for creating contours in QGIS because I find the contours generated by the contour plugin a bit strange (very sharp edges and whatnot). I can't ...
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475 views

Interpolating in QGIS 3.8.1

I have a problem with getting an Interpolation with the Interpolation Tool on QGIS 3.8.1-Zanzibar. I just performed an IDW interpolation via the QGIS toolbox, with values from a layer that are 18 ...
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67 views

IDW interpolation using QGIS?

I want to obtain the quantity of precipitation for each municipality in Brazil on a given year. For that, I'm trying to use IDW interpolation on QGIS to interpolate the precipitation data from weather ...
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1answer
37 views

Iterating through table for IDW says parameters are not valid?

I have a table with precipitation data from 5 weather stations and I am trying to iterate through the table to perform IDW on each field (month of precipitation). import arcpy from arcpy import env ...
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258 views

IDW in QGIS 3.8

I'm trying to create raster interpolated layer by using the IDW tool. this is how my original points layer looks like: this is what I did in order to get the IDW interpolation: and this is the ...
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1answer
478 views

How to fill the gap by using IDW(inverse distance weighting method) in R?

I'm beginner of R. I'm trying to fill the gap using idw, but I still had no idea about this. The data in used is below: The names sequence of columns are date/SO2/CO/O3/NO2/PM10/Lat/Lon. As you see, ...
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How to calculate kriging weights?

In Esri's documentation on how to make a prediction in Kriging, I couldn't figure out the linkage between the semivariograms and the prediction process from reading the description therein: After ...
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238 views

Performing Inverse Distance Weighted (IDW) interpolation in Google Earth Engine?

I would like to know if interpolation like in the image below is possible to produce in earth engine. Can someone tell how to get it done because I can only do it in ArcGIS and QGIS. I found this ...
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522 views

R - IDW interpolation using gstat

It contains two coordinate columns dist for distance in x direction and rel_alt for an altitude in y direction. The other two columns are the data points for each combination of those two coordinate ...
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Using GRASS v.surf.idw in PyQGIS? [closed]

I have a point shapefile I am trying to run the GRASS v.surf.idw tool on in python. Here is a link to the data: https://github.com/tanyahelena/qgis_data I have a short script which runs. I don't get ...
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52 views

Interpolate Line Tool giving different results?

I have been using 'Interpolate Line' Tool in the 3D Analyst tool pack to create a profile graph so I can analyze interpolated results gathered from an IDW created surface. However, when I use the tool ...
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Creating IDW of up to 20,000 points in ArcGIS Desktop? [closed]

I am create IDW interpolation of 60-70 points in ArcGIS. It takes 2 minutes. But when I create IDW of 20000 points in ArcGIS, it takes at least 4 hours and 30 minutes. I want to ask why takes much ...
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1answer
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Running IDW, but values are '<1' not 0.934 so they are Strings not Doubles

I am trying to use some interpolation tools for analytical data of concentrations of Benzene for monitoring wells. A decent amount of our values for Benzene are '<1' (not 0.943 or 0.345) because of ...
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61 views

Creating IDW-rasters from each field in large point feature set using ArcPy for ArcGIS Pro? [closed]

I am using ArcGIS Pro 2.3.2 I am trying to automate the process of making a raster (IDW tool) in model builder by iterating through fields as z-value. I saw some other question asking the same, and ...
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1answer
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Why is raster boundary rectangular, not buffer?

First, I took very few points and did IDW and i got a circular boundary raster. This is because of the search radius i applied. If that is the case, for large number of points, the raster must look ...
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1answer
171 views

Interpolation of data points

I have a layer of points that represent bus stops. Each point has a value (quality of service, between 0 and 100). I need to create a grid (resolution 25m) by interpolating the points values. For ...
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43 views

How is IDW raster formed?

IDW algorithm says that it makes a grid and assigns value to each point in grid depending on the distance of separation. From this definition, it looks like the output is set of equally spaced points. ...
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1answer
67 views

Why is the ArcMap IDW tool interpolating values higher that it's closest data points

I have a dataset of equally spaced, by 3 arcseconds, points. Each point represents the radio signal strength from a near by transmitter. I wanted to convert the point data set into a raster for ...
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8k views

Picking coefficient in Inverse Distance Weighted method of QGIS?

I'm using QGIS 1.8.0 to interpolate weather data. This is, I have a weather station located in say, A and C. With the Inverted Distance Weighting or Triangular Interpolation methods, I can know/...
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1answer
77 views

Default parameter values in r's gstat idw?

In r, gstat has an Inverse distance weighted (IDW) interpolation method. Does anyone know what the default values of nmin, nmax and maxdist are?
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481 views

Making data table using linear kriging interpolation with variogram in R

I have a table of data with such structure: longitude_for_data = c(32,68,89,145,176, -14, -42) latitude_for_data = c(22,98,21,13 , 16,-134,-102) Z_for_data = c(30,40,60,70 , 20, 40, 100)...
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1answer
55 views

Including buffer to IDW in ModelBuilder

I have created a model with ModelBuilder to interpolate values with the IDW tool, iterating through rows. How can I restrict interpolated values to regions within a 20km buffer? I tried setting the ...
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2answers
510 views

How to use GDALGridInverseDistanceToAPower in a python script

I'm trying to use GDAL in a python script to do an inverse distance interpolation. Within the C documentation API I found GDALGridInverseDistanceToAPower function but I don't know how/if I can call ...
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84 views

Improving IDW and Sample Model using ModelBuilder?

I want to create a dataset of estimated values using inverse distance weighting. I am starting with a dataset of daily values of measurements for specific coordinates. I created a model (below) which ...
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1answer
32 views

Building model to select values at point from folder of several raster layers?

I am using ModelBuilder to interpolate values with inverse distance weighting, iterated through several rows, resulting in many raster datasets - one raster layer per row. I have this and all the ...
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1answer
54 views

Finding creator of Inverse Distance Weighted method?

I am interested in the very first person who invented the Inverse Distance Weighted method or the very first reference that this method was mentioned. I tried to search on Google but could not get ...
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2answers
301 views

What does 'Weight Field' in IDW interpolation mean?

I am trying to figure out how the Weight Field option of Geostatistical Analyst IDW in ArcMap 10.3 works. On IDW - ArcGIS Desktop Help I can find just this simple explanation: Used to emphasize ...
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1answer
106 views

Using Row Iterator and IDW in ModelBuilder?

I am using ModelBuilder to perform inverse distance weighting. I would like to interpolate values using a point file with values for several unique dates - resulting in a raster dataset for each ...