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

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R: how to correctly set number n for 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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17 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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8 views

Using IDW method and its output raster in a web app

I am creating an web app and needs to interpolates between some points- Weather data- (with IDW method) and show the results as a raster (like the output from ArcGIS) so a user can click on raster and ...
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2answers
48 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 ...
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56 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 ...
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62 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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53 views

Is there a minimum number of required samples/ data points for IDW Interpolation in ArcGIS for Desktop?

I am interpolating air pollution values from 6 data locations using IDW in ArcGIS. I know that more the number of points, more reliable the results are. But, I am not sure if a minimal number of data ...
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88 views

Does IDW interpolation in ArcGIS Geostatistical analyst work as exact interpolation method?

As we know, Inverse distance weighted (IDW) is an exact interpolation method, which means the interpolated values of the known samples should be the same with its original observed values. But when I ...
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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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55 views

How can I get the value of a point that falls between 2 points of another layer?

How can I get the value of a point that falls between 2 points of another layer? I have a Shapefile of points with values representing the distance from an origin (blue in the example bellow) at ...
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118 views

Difference in contour lines derived from IDW and TIN in ArcGIS for Desktop?

I would like to know the difference between contour lines derived from IDW and contour lines derived from TIN. I have collected GPS points, and I know the elevations are not accurate but it is within ...
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80 views

error while using idw geoprocessing tools of Arcobjects with java

I am trying to use idw geoprocessing tools to generate a raster file, but it doesn't work fine for me. I have got a input point shapefile named "TrafficMap_Count.shp" which has a WGS84 coordinate ...
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73 views

Avoiding pixelation of results following Extract by Mask or Clip tools?

I need to clip my IDW results to the boundaries of my survey areas. However, whenever I use the Clip or Extract by Mask tools, my results become pixelated and lose accuracy. Is there some way that ...
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36 views

Interpolation method for independent and dependent variables, in ArcMap? [duplicate]

I'm relatively new to ArcMap, and I'm looking at the relationship between the internet and health outcomes. My dependent variables for my regression come from the Demographic & Health Survey (DHS) ...
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109 views

How to interpolate data using quantum gis?

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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105 views

How to create contours from an IDW raster

I'm new to QGIS and am trying to create vector contours from this IDW raster. I followed Ujaval Gandhi's "Interpolating Point Data" tutorial step by step but am not getting the same results for step ...
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133 views

choice of number of neighbors in IDW

I am not so familiar with 'interpolation' math, albeit I grasp the underlying logic. I was wondering if there is a rule of thumb in the choice of the number of neighbor points to use in IDW ...
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81 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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30 views

Strange interpolation with natual-neighbor metod

I have base shape file 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 ...
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74 views

Why does the use of barrier lines significantly increase idw processing time?

The IDW tool's documentation states that using barrier lines will significantly extend the processing time. It does not explain why this happen. Is anyone able to provide an insight into the inner ...
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1answer
64 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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50 views

How to publish a IDW GP service with python in ArcGIS 10.1?

I know someone has ask a question about how to publish a gp service with python.And the answer is using arcpy.CreateGPSDraft. But My geoprocessing tool is IDW, and I find the return value isn't a ...
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57 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 the ...
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127 views

Interpolated raster not aligned with the vector data (QGIS)

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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287 views

Soils sampling. How to make polygons from interpolated points?

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

Looking for a tool like (IDW) for raster

I am looking for a tool that gives the same outputs like the IDW, but for rasters instead of points. I have a Corine land cover raster layer in ArcMap 10.2 with different friction values, displaying ...
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125 views

Problems applying a mask in 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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Use of ArcGIS Getis Ord Gi* and IDW tools with “hotspots” where unmeasured areas are “coldspots”

I am new to this forum and perhaps someone can be of help. I have two datasets that I would like to analyze together. The first dataset has bird nest locations in neighborhoods (nest). The second ...
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166 views

IDW with QGIS from a vector points file within a mask

Given two inputs: A shapefile: points A raster: mask I want to interpolate the points within the extent of the raster except the NoData pixels that i want to use as a mask. NoData pixels are the ...
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231 views

Add Layers to Map Display from script with default symbology

I have a script that runs IDW iterations and I'd like for the files to be automatically added to the map display after they are produced and contain the default symbology that ArcMap generates when ...
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115 views

Interpolating species data from sample points in a small area [closed]

I have sample data from a small site (10 acres) which shows the number of occurrences of a particular species of snail over two sampling periods (fall and spring sampling). I want to try and ...
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142 views

How do I iterate a model over multiple fields using ModelBuilder? [duplicate]

I have built a model to interpolate air pollution from 40 recording stations using IDW. The results are then exported to an average for census divisions. I need to repeat this process hundreds of ...
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41 views

Interpolating points to surface not working

I am trying to create a surface from points using IDW interpolation. Have tried both 3D analyst and Spatial Analyst tool with my selected xyz data sheet. It appears to process and I don't get an error ...
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124 views

Parameters for optimizing interpolation in ArcGIS for Desktop?

Is there any criteria to know the most proper parameters for an interpolation method in ArcGIS (such as, for IDW: Neighbors (min and max), sector type, semiaxis length, angle, search neighborhood)? ...
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268 views

Cross-validation and optimal p power in IDW

I use the "Geostatistical Wizard" in ArcMap 10 to do my interpolations. For example, when I do IDW and I want to decide for the optimal p power or the optimal number of neighbors that will contribute ...
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605 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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590 views

Cell Size parameter for IDW (Spatial Analyst) tool

I am attempting to use the IDW (Spatial Analyst) tool in a Python script however I am a bit confused on what to put for the "Cell Size" optional parameter. When using the tool within ArcMap it seems ...
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2answers
626 views

How to interpolate population data?

I have population data (inhabitants per city and year) of 31 cities of the DR Congo for the years 1960, 1970, 1980 and 1990. I want to interpolate the population of all cities for the year 1990, to ...
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182 views

How to perform IDW interpolation and mean estimation on county level using ArcGIS for 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
80 views

How to export a IDW raster while keeping the search radius data

I want to export my IDW rasters that I made in ArcGIS to QGIS, however when I export my raster, the values are there but are no longer displayed. They are stored within each cell and are not ...
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3answers
658 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' one for measured noise data? I prefer to ...
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209 views

Problems with IDW Tool in ArcGIS

Everytime I use the IDW it doesnt visualize the Interpolation. It is calculating everything properly but there is nothing shown on the screen. i did everything i have to do in the enviroments raster ...
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1k views

What's wrong with my IDW interpolation function (Python)?

Original Question Can anyone see what's wrong with my custom IDW interpolation below? I know there are existing libraries that can do this for me, but for various reasons including educational and ...
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254 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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9k views

When to use 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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496 views

Using ArcGIS API interpolation functions (idw, kriging, splines) in my own dataset?

Does ArcGIS API provide interpolation functions, like if I want to interpolate from my own set of values? I know that ArcGIS provides functions for interpolation like IDW, Spline and Kriging etc, ...