Questions tagged [inverse-distance-weighted]

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

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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
310 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
116 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
704 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
413 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
215 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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2answers
416 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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0answers
257 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
61 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
318 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
2k 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
1k 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
278 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
262 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
246 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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1answer
29 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
510 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
161 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 ...
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1answer
287 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?
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1answer
804 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 ...
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1answer
688 views

How to make polygons from interpolated points?

My goal is to make a shapefile with polygons for variable rate fertilizer application within a farm field. I have a point shapefile with soil sample values (pH, P, K and so on) and a line/polygon ...
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2answers
634 views

Iterating through z-values in ModelBuilder

I have a series of fields that I am trying to run the IDW tool against. I'm looking for a way iterate through the feature class, using a different field as the z value each time. This is my data: ...
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0answers
63 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-...
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1answer
63 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 ...
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1answer
320 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 ...
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0answers
59 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 ...
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1answer
2k views

Creating a python script to import an excel spreadsheet, create shapefile and do some analysis [closed]

I am trying to write a script that does the following. Imports an xls file containing x, y, and other columns with data. I want to make this into a point shape file. I want to take that point ...
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2answers
453 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 ...
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1answer
117 views

Interpolating points conditionally

I have two sets of data. One comprises all home sales in a given area, where each data 'point' is actually a polygon representing the lot that was sold. The other set comprises arrests made in the ...
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1answer
2k 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 ...
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2answers
292 views

Performing IDW interpolation and mean estimation on county level using ArcGIS Desktop?

I am absolutely new to GIS. I have imported a map with information in the counties of Germany. Additionally I have added a layer with information on SO2 concentration at various measuring stations in ...
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1answer
479 views

Interpolated raster not aligned with the vector data

I have loaded some tab delimited text data into QGis to interpolate the points. When I get to the interpolation (IDW) part everything breaks down. The output raster file does not align with the ...
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3answers
2k views

Which interpolation method for noise mapping?

I want to create a noise map with measured point data. But I want to have a planar representation, so I need an interpolation method. Which one is the 'best' for measured noise data? I prefer 'IDW'...
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1answer
76 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 ...
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1answer
33k views

Choosing IDW vs Kriging Interpolation for DEM creation?

I'm trying to create a DEM using point data spaced very regularly about 10m apart. The area I am interpolating is an educational facility with many flat parking lots and football fields but still has ...
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2answers
3k views

Interpolating data using QGIS? [closed]

I am trying to interpolate distribution value of rain using IDW (inverse distance weighting) method using quantum gis. What steps do I need to undertake? The input layer data which I used there are 2 ...
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1answer
875 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 ...
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1answer
740 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?
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0answers
96 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 ...
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1answer
1k 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 ...
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1answer
866 views

SAGA Inverse Distance Weighting in QGIS - How to Set Minimum Number of Points?

I am analyzing a postGIS point dataset in QGIS version 2.8.2, about 200k features total. To calculate weighted average values I am using the Inverse Distance Weighted interpolation technique. However, ...
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1answer
348 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 ...
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1answer
766 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 ...
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2answers
476 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 ...
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0answers
41 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.
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1answer
156 views

How do Natural Neighbor and IDW assign values to pixels?

According to ESRI's help files, NN interpolation calculates a value for a "query point", yet the output is ofcourse a raster. I understand how the value of this query point is calculated based on ...
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1answer
699 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 ...
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1answer
759 views

Applying mask in ArcGIS Geostatistical IDW?

I'm finishing an analysis of approximately 850 archaeological assemblages in the Mediterranean, and I've successfully run IDW in Geostatistical toolbox (ArcGIS 10) to generate the results I like. I'm ...
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2answers
202 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 ...
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0answers
351 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 ...