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Questions tagged [spatial-interpolation]

Estimating new data points based on existing spatial observations

Spatial interpolation is a method of estimating new data points based on existing spatial interpolation. This tag focusses on spatial interpolation (data with a geographic component), although interpolation in a general also applies to e.g. timeseries.

Commonly, spatial interpolation involves using of the surrounding observations to estimate a new data point. This can be done using some kind of weighted mean (inverse distance weighted interpolation), by fitting a mathematical function through the existing points (splines), or a combination of both (kriging with external drift).

More information regarding which packages can be used to perform interpolation can be found on the Spatial Task View on CRAN, but in general the gstat, automap, Fields, and geoR packages are a good start for a wide range of spatial interpolation methods.

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R: Bad variogram fitting, bad kriging results

I try to do a kriging in the Jakarta Bay. I have a set of measurement points with appropriated coordinates and attributes (pH, salinity,...) In order to do a kriging I first need to find a model for my variogram. When I use the "variogram" function…
ZKB
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Three-variable interpolation in java similar to matlab interpn() or interp3()

1. Consider six different vectors float[] xRef, yRef, zRef and float[] xTest, yTest, zTest, representing a positions grid. For each set of the Ref and Test vectors a vector dataRef and dataTest exist that hold data for the respective mesh. 2. My…
Peter
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Spatial Interpolation of gridded data to county data: MATLAB

I have gridded precipitation information available at 2 degrees monthly. I need to interpolate precipitation data at each month at each grid points into US county scale. The US here I mean mainland US leaving Alaska & Hawaii.
user962808
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How to perform Looping for idw in R

I have a data frame which contains point daily precipitation for 4 station for 2 years. I want to interpolate to 50m resoulution and write them in to 2 raster images. I used following code to achieve…
user3978632
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Is it possible to do linear interpolation for a function of more than one variable in R?

In practice I need an extension of the approx function that already exist in R to the multivariate case. Something similar to the interp function in matlab but coded in R on in C. Hope somebody can help me!
Sabrina Vettori
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Plotting Interpolated spatial distribution of electric potentials measured from a sensor array

I have a small footprint EEG measurement device with 8 measurement electrodes and 1 reference electrode - the reference electrode is in the center of the sensor array, 4 measurement electrodes on the corners of the 2cm x 2cm sensor array and 4…
Naveen
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To Assign a pixel value to a noninteger coordinate in an image in MATLAB

salam i am having an issue regarding assigning of value in MATLAB. i have a 5x5 image, i want to increase its size by 2 using surface approxiation in delaunay triangulation i used a bivariate polynomial for interpolation , for each triangle 9…
Jav
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Higher order interpolation for contour plots in python

Is anybody of you aware of a higher order interpolation method (Catmull-Rom splines, cubic interpolation, etc.) for 2D contouring in Python? Skimage, Matplotlib, and OpenCV provide the functions measure.find_contours(), contours() and…
Gustavo Chavez
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re-project SGDF with 5 km*5km resolution to 0.05*0.05

Forgive me for me being naive. I am having trouble with re-projecting SGDF. I have an xyz (x=longitude, y=latitude, z=value) 3-column dataset. Longitude and Latitude values are coordinates in EPSG:3035 format. I converted the data frame into a grid…
Nav
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autokrige and proj4string

I am using the R function autokrige from automap package, but I got an error and I do not know how to solve it. Do you have any hints? Thank you! sp.poidf <- SpatialPointsDataFrame(sp.poi,thresh.df) proj4string(sp.poidf) <- CRS("+proj=longlat…
user1634468
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Create colour Grid over map in R

I have been trying to create a grid over my world map in such a way as shown below example of gridded map I want to be able to colour the grid based on the rate2 column in my file. Most of the solutions I have gotten only colour the world based on…
user1554062
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2D Interpolation in Python with irregular ordinate

I have data in the format: X1 X2 Y a1 b11 b12 y11 y12 a2 b12 b22 y12 y22 a3 b13 b23 y13 y23 I am trying to build a 2D interpolation tool such as y=f(X1, X2). I was wandering what is the best 2D interpolator in Numpy for this:…
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Seeking algorithm for optimal 2D spacing of agents among fixed locations

I'm designing a program where each of N agents is assigned a value K. There are N fixed locations, each with coordinates (x,y), and each location is assigned one agent. What algorithm could I use to distribute all agents among the locations such…
lhammer
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Interpolation with MATLAB in EMG processing

I have 3 EMG recordings for 2 muscles, with a sampling rate of 1000Hz. In other words I have 3 matrices of EMG data; each has 2 rows (for 2 muscles). However the number of samples (columns) in each isn't the same: the first one has 2600 samples, the…
neda
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