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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50 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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222 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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1answer
101 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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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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47 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
23 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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1answer
93 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
87 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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2answers
524 views

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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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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197 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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1answer
41 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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26 views

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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Cross validating part of spatial interpolation?

I am very new to ArcGIS Desktop . I am exploring some of the spatial interpolation techniques like IDW and Kriging. My query is on the cross validation part of the techniques. In the cross validation ...
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1answer
135 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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1answer
24 views

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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1answer
33 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
27 views

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
108 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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1answer
32 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
47 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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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
50 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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2answers
348 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
34 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
237 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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80 views

Using spline / IDW interpolation for bathymetric profile of lake bed in ArcGIS Desktop?

I have partial bathymetric / topographic coverage at 1m resolution of a lake bed and shore and am trying to find an appropriate method for 'filling in the gaps'. I have tried using the following in ...
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1answer
48 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
27 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
44 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
223 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
67 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 ...
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2answers
222 views

Understanding Inverse Distance Weighting Bulls Eye Effect?

Is the Bulls Eye Effect generally caused by a sample point with a high value being too far from other sample points? Or rather a sample point with a higher value than others close to it? What ...
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1answer
190 views

Expanding IDW interpolation to borders of country in ArcGIS Pro? [duplicate]

I am new to ArcGIS. I have a data set with air pollution concentrations for 20 locations in the Netherlands. I would like to interpolate this data with IDW, so that I can estimate the approximate ...
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1answer
170 views

Understanding symbology in IDW interpolation using QGIS 2.18

Continuously to Understand ramp color interpolation using QGIS 2.12, I used IDW interpolation on those height point without inserting the real values (minimum value is 8 meters, maximum value is 584 ...
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Making error or confidence surface in ArcGIS Desktop?

I have a student working in my GIS lab who is computing an IDW interpolation surface for observations taken from a boat moving along a series of paths. The sampling paths were not uniform over the ...
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2answers
345 views

Using buffer from IDW in ArcGIS 3D Analyst for flood spread?

I have a line in the centre of a road, with the roads elevation attached to its properties. By using Generate Point along lines --> Add Surface Information --> Adding 10 cm to that, and then IDW 3d ...
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152 views

Interpolation in QGIS shows wrong output result [closed]

I have done interpolation (IDW and Nearest Neighbour) in QGIS. But interestingly the output shows the wrong result. The area where I have a huge number of points results in a lower Z value (it is ...
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0answers
59 views

Strange interpolation with natual-neighbor method

I have base shapefile and try to use different interpolation methods to get image like this: This layer is constructed using point to raster conversion. Generally, interpolation methods as idw and ...
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1answer
210 views

IDW Interpolation pyqgis QGIS3

I try to create a interpolation with the follow script, the problem is that when the program tries to write QgsGridFileWriter, qgis crashes. The problem is that the different examples are to lower ...
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2answers
1k views

IDW Interpolation in QGIS [duplicate]

I'm using the Interpolation plug-in in QGIS 2.18 to perform IDW Interpolation. I was hoping to specify a power of 2 and use the 10 nearest points to calculate the output, but I don't necessarily see a ...
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1answer
959 views

Create a rainfall raster with gstat or idw in R

I am a beginner in R, I need to use gstat or idw function to get a rainfall raster, but I have an error in the formula. How can I change it? This is my code: setwd("C:/Users/A/Desktop/...
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1answer
193 views

IDW with buffer in QGIS

I'm very new to QGIS and am having some issues using the SAGA IDW tool. I'm attempting to perform an interpolation using the 10 closest sample points and an inverse distance power of 2. I would like ...
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1answer
238 views

give importance weighting to sample points in an IDW-interpolation

I am trying to make an IDW-interpolation in arcgis 10.1. In my sample file i have points with the same x,y and z values. According the arcgis-resource-site, the points are considered duplicates and ...
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1answer
136 views

Cannot add ArcGIS ModelBuilder output to table of contents

I've made a model that creates some points with Z value and a buffer, which I then do a 3D analyst IDW on, and a Cut Fill analysis. The model input is a line along with af DEM/Raster, and some names ...
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28 views

IDW possible to fill out buffer area?

I've got a lot of points with Z-values, where I would like to construct their extent using IDW (or similar). I would like to see their extent inside my buffer, is this possible or is the tool not ...
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1answer
347 views

Extrapolating with IDW (Feature Classes) in ArcGIS Pro?

I have been struggling to extrapolate beyond the extent of the point features input into the IDW tool of ArcGIS Pro. I believe IDW interpolation is the method for me, i just need the process to ...
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1answer
134 views

Why v.surf.idw returns only two value (one is nan)

I am trying to perform a vector interpolation of a point shapefile with the intent of eventually creating a DEM. No matter what I try, I get only 2 values one of them is NAN, and nothing is working to ...