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Questions tagged [inverse-distance-weighted]

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

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0answers
25 views

IDW interpolator [on hold]

X=19, Y=66 and P=2. Apply IDW to compute height at X (SAMPLE POINT, X-COORDINATE, Y-COORDINATE, HEIGHT-VALUE) (11 , 41 , 60 , 56.90) (14 , 21 , 40 , ...
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0answers
13 views

Performing IDW Interpolation in ArcGIS Desktop? [on hold]

With inverse distance weighting interpolation, can the number of sample points used to interpolate a value at a given location be set according to minimum number of points? Or could you set sample ...
5
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2answers
45 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 ...
0
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0answers
34 views

spatial zones interpolation

I work on QGIS platform and I have a question regarding presenting my spatial data. my data contain: vector layer of points that were taken in a field contain very dense data (see picture). I ...
0
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1answer
32 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 ...
2
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1answer
38 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 ...
0
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0answers
29 views

Format of data for doing the IDW interpolation in R

I have time-series of precipitation for a 30-year period for three climate stations that are situated out of the catchment of interest. I have to obtain the spatial distribution of precipitation, the ...
1
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1answer
32 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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0answers
20 views

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 ...
0
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0answers
39 views

Interpolate a time series data using IDW in QGIS

I have a data series that corresponds to the daily precipitation measurement of three stations over the course of thirty years. The stations are out of my geometry of interest (out if the catchment I ...
0
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0answers
37 views

What is the procedure for getting IDW raster from group of points?

It is clear that the IDW uses inverse distance based average to get value of a particular point. However, the algorithm also provides interpolated value for an area by specifying x limits and y limits....
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0answers
60 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 ...
1
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1answer
103 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 ...
0
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0answers
28 views

Using Kriging Tool for estimation in ArcGIS Desktop?

I'm working on an Exploration Project where i have few information about underground geological layer (for example: Phosphate). The wells with brown color present the known data (That we'll use for ...
1
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1answer
50 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 ...
0
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2answers
471 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 ...
2
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1answer
68 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 ...
0
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1answer
24 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 ...
2
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2answers
270 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 ...
0
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1answer
82 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 ...
1
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1answer
87 views

Checking accuracy of IDW using ArcGIS Desktop?

I performed IDW using ArcGIS on 121 evenly distributed samples and generated a surface. How do I check the accuracy of the method?
0
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1answer
166 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 ...
4
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2answers
232 views

How to make a prediction in Kriging using a semivariogram?

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 ...
0
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1answer
44 views

point count from in Inverse Distance weighting procedure - QGIS

I have conducted an interpolation using IDW procedure. I have vectorized the interpolation in order to be able to specify a 3 class clasification. I have additional point dataset indicating the ...
0
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1answer
136 views

IDW Interpolation in QGIS gives weird values

I'm trying to do an IDW interpolation with QGIS tool. But i'm really surprised by results. Interpolation values aren't similar as shape values. I used a power of 0.2 to get a smooth raster. Somebody ...
0
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1answer
598 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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0answers
37 views

Constraining an IDW interpolation [closed]

I am running an IDW on a data set that represents point values of water current speed. I would like to run the IDW only within the water area of another shapefile that shows the shape of the water ...
0
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1answer
123 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 ...
0
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2answers
233 views

Extrapolating surface in ArcGIS Desktop?

I'm trying to calculate the volume of a landform under water in ArcGIS and here's what I decided to do: Convert the raster of the bathymetry that I had to a gridded point dataset using Raster to ...
3
votes
1answer
451 views

SAGA IDW interpolation algorithm has been changed?

Yesterday, I try after a long time to make an IDW interpolation on a point layer in Qgis 2.18 with SAGA tools. I use same parameters as before on Qgis 2.14, but the result is quite different. Raster ...
1
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1answer
1k views

Creating Digital Elevation Model from Contour Data using QGIS? [duplicate]

In ArcGIS I used to create DEMs from contours with ease. However, we recently opted to stop using ArcGIS (for various reasons), and switching to QGIS. The reason I use contour data is it is all ...
0
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0answers
137 views

Using IDW with ModelBuilder?

I am attempting to create some groundwater elevation rasters using IDW. There will be a raster for every month for about the past 10 years. Since readings are taken from wells once a month, I normally ...
0
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0answers
126 views

Cross validation: Spline with barriers

When interpolate a raster surface, using Spline with barriers it is possible to run cross validation for this method? I have a raster and i want to find the RMSE for IDW and Spline with barriers in ...
2
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1answer
549 views

IDW interpolation of values from raster in ArcGIS

I've been tasked with obtaining z-values for a large point set from a 2 m raster, but rather than extracting values directly from the raster, or with bilinear interpolation, I've been asked to use ...
1
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1answer
142 views

Seeking algorithm for IDW Weight Field Option of ArcGIS GeoStatistical Analyst?

I am trying to figure out how the weight field option of geostatistical IDW works in ArcMap 10.3. On IDW - ArcGIS Desktop Help I can find just this simple explanation: Used to emphasize an ...
1
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0answers
52 views

Cross-validation error threshold in ArcGIS

I'm learning the Geostatistical Wizard toolset in ArcMap 10.4.1 and I am performing the cross-validation step in an IDW interpolation. I have done some research regarding the process of cross-...
2
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0answers
67 views

WEKA for IDW evaluation IN QGIS

intento evaluar una interpolación IDW realizada en QGIS y desconozco la manera de validar o evaluar su ajuste (y con cuales herramientas). Pero he descubierto WEKA como una alternativa para la ...
2
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1answer
55 views

Elevation profile and chemical concentrations

I have a IDW layer showing the pattern of a chemical concentration. I have also created an elevation profile across the same area. Is there any way to include the IDW measurements with my elevation ...
1
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1answer
808 views

What is the unit of “output cell size” in IDW in ArcGIS?

I have a wind speed point data which I interpolated using IDW. While interpolating, it asks for output cell size. I am confused as in it is in which unit? My data is in UTM projection and WGS 84 ...
1
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1answer
200 views

Inverse distance weighting variable search radius based on third variable [closed]

I am trying to perform inverse distance weighting (and possibly kriging), but want to base the search radius on a third variable: high population density -> small search radius low population density ...
3
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1answer
503 views

How to compare a TIN and IDW-derived raster DEM quantitatively?

I'm a student and got the assignment to compare a TIN with a height raster 'quantitatively' and I'm not quite sure how to proceed. I tried subtracting the one from the other but it doesn't seem to be ...
2
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0answers
33 views

Determining search variable when using Inverse Distance Weighted Interpolation? [closed]

When using IDW interpolation in ArcGIS, how should I determine the number of nearest input sample points to be used to perform interpolation? The default number is 12, but it may be incorrect.
1
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0answers
279 views

ArcGIS Interpolation IDW and Spline, extreme values [closed]

I am trying to interpolate air pollution data that is displayed in 1x1 Km points in ArcGIS. I am having two issues: When I try to interpolate using IDW, the software freezes at 94% "building search ...
1
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0answers
111 views

Understand ramp color interpolation using QGIS 2.12

I try to understand the color ramp in TIN and IDW interpolation. I work with height points layer. The low value in 8 and the highest value is 584. With the interpolation plugin i create TIN raster ...
6
votes
2answers
173 views

Why do I get a shattered-glass effect when I turn on hillshade for my IDW surface?

I made an interpolated IDW surface with a cell size of 500. In the symbology tab of ArcGIS, there is the "Use hillshade effect" checkbox underneath the classification area. When unchecked, my surface ...
4
votes
2answers
332 views

Defining number of cells in sample grid for IDW?

I'm trying to make IDW in R. In my tutorial, I found this approach which is easily understandable, expect of one point - why they used n = 6000 ? How did they established the value to create a grid ...
1
vote
1answer
441 views

Specifying the “idp” and the “nmax” in the krige.cv function

I'm performing IDW interpolation using the idw R function from the gstat package. For the purpose of determining what combination of "idp" and "nmax" produces the lowest RMSE in leave-one-out-cross ...
2
votes
2answers
258 views

Getting similar IDW results using Spatial and Geostatistical Analysts for spatial interpolation of data with many zeros?

My data are plant biomass data from hundreds of sites. Most sites have zero biomass; these zeros are real. Thus, my data violate most assumptions of geostatistical interpolation methods (confirmed ...
2
votes
1answer
749 views

Inverse Distance Weighted (IDW) Interpolation with Radial Basis Function (RBF) in R

I want to perform an IDW interpolation with R. I am aware that I can do that with gstat::idw. But I want to change the parameter 'idp' with a radial basis function (RBF): where is the ...
2
votes
1answer
556 views

How to automate the QGIS Raster Interpolation Plugin using python console?

I have a rainfall data from 1961 to 2015 for each day of this years. I need to create a raster for each day with this configuration. Do you know how to automate this using this plugin and python?