# Questions tagged [variogram]

A plot or function used in spatial statistics (or in time series analysis) to describe the degree of spatial (or time) dependence of a stochastic process.

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### Checking for temporal autocorrelation in experience sampling data - how to interpret the variogram?

I have day-level data from about 100 participants from 11 days (EDIT. a subset of participants responded for 12 days, which is why there's a distance of 11 in the variogram table). I'm interested in ...
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### Creating a Variogram-like plot with distances

I have a dataset of points in space, sampled at a specified time. Now i want to obtain a 'spatial correlation plot, only between points close in time'. What i did is creating a dataframe of pairs of ...
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1 vote
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### Geostatistics: Covariance vs Semivariance

I am confused by the following page in Geostatistics for Environmental Scientists, Webster & Oliver: My understanding Given locations specified by a vector $\mathbf{x}$, we assume an underlying ...
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### How do you express the variogram $\gamma(h)$ in terms of correlation taking into account also the nugget

let's say that I have a spatial random field $z(\textbf{x})$ with $\textbf{x}$ the spatial coordinate. I can define the semi-variogram as: $\gamma(h)=\frac{1}{2}E[(z(\textbf{x+h})-z(\textbf{x}))^2]$ ...
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1 vote
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### Declustering spatial data and kriging

I am doing a simple project on a mining dataset and came across some problems: Should I use the declustered values to model the variogram? Do I apply ordinary kriging to the original or to the ...
1 vote
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### Decreasing trend in semivariogram of nlme model residuals?

I am new to spatial statistics and am trying to fit some spatial models using the nlme package in R. I fit three different models, using the same set of predictors ...
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### What am I not understanding about semivariogram and Normal Score Transformation?

I have generated this two dimensional random field: This is done following this page. In particular, I have selected t=23 as dataframe and I have changed some parameters. As you can noticed, I have ...
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1 vote
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### Generate a syntetic log-normal two dimensional random field

I would like to test some functions that I wrote related to the kriging applied to rain data. In order to do that, I would like to generate a synthetic log-normal 2D random field. The idea is to ...
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1 vote
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### Empirical bayes estimation of variograms for multiple variables

I am looking to estimate variograms, or spatial correlation matrices on all columns of a data matrix $\mathbf{X}_{n\times p}$ with $p>n$. The matrix of spatial coordinates $\mathbf{Y}_{n\times 2}$ ...
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1 vote
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### Residual autocorrelation in non-stationary (gaulss) model

I'm fitting a non-stationary model using mgcv (family: gaulss()) where the data have been collected at different points in space....
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### How do you express the variogram $\gamma(u)$ in terms of correlation for a stationary process?

The Analysis of Longitudinal Data textbook by Diggle et al. (2002) mentioned twice (p48 f. and then on p82) that given the following definition of the variogram, \gamma(u) = \frac{1}...
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### No convergence when fitting theoretical semivariogram to empirical?

I'm kind of new to working with semivariograms. But I just wanted to fit a semivariogramm to my data and when fitting the theoretical variogram to my empirical it tells me that: ...
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1 vote
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### Interpreting a Distance & Time 3D Variogram for Variogram modeling

I am trying to understand some concepts of variograms. I have made several variogram models in R and am trying to understand exactly what they mean. My data is ...
• 181
1 vote
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### Variogram fit in R not converging

I have taken a shapefile from Open NYC Data and performed the following method. My end goal is to predict Taxi trip_duration at various points across the city of ...
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### Variogram of categorial data?

I have a thematic map as raster data with classes assigned as numbers: 1,2,3,4. These are categorial classes and have no linear meaning. I am interested if there is spatial autocorrelation in this ...
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### Is there an approach to combining variograms?

If we compute two seperate variograms for the same type of measurement, but the areas which they cover overlap, is there a logical way (or does it even make sense) to combine the two variograms? ...
310 views

### Why is my semivariance so high?

I am using variograms checking for spatial autocorrelation in a resiudal pattern produced by a GLMM-NB. In theory, the semivariance should be bounded between 0 and 1 (that´s what I think at least as I ...
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### What does it mean that a variogram keeps increasing with distance?

I am modeling my 3D dataset with a Gaussian Process with square-exponential covariance. To test whether this is a good model, I subtract the mean from the observed data and then calculate the ...
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1 vote
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### Kriging: fit.method and dX argument in variogram

I would like to krige residuals (from multiple linear regression) of yearly precipitation totals from a 50 years time series. Every year has been regressed individually. The residuals will be added to ...
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### Interpreting Spatio-Temporal Variograms

I've got spatio-temporal disease data at the county/annual level for 2000-2014. I'm analyzing it to try to pull out temporal variations in disease incidence and was told that I should generate a ...
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### Variogram with custom distance matrix

I work in marine ecology and as such all of my distance matrices are constructed using the shortest possible marine route - i.e. avoiding any land. Here is a plot of my "marine distances" against "as ...
33 views

### Critical scale of variation of tree biomass using variography

I have a combination of a philosophical and a technical question. I am interested in an application where I am trying to find a critical scale of autocorrelation of tree biomass on the landscape. Let’...
563 views

### Gstat: Modelled semivariogram values not matching plotted model using the variogramLine function

I am trying to extract the semivariance values associated with a given semivariogram model developed in gstat, the end goal being to compare modelled semivariance with observed semivariance at defined ...
176 views

### Gaussian Mixture Model: bandwidth parameter versus variogram fitting?

I'm estimating a stationary, spatially random variable over a 2-dimensional domain. I have ground-truth measurements in several locations, over time. I need some way of spatially-interpolating ...
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### Simple Kriging with linear semivariogram

While studying how to develop a simple kriging model with a linear semivariogram, the various tutorials point towards creating a covariogram using $\sigma(h) = \sigma(0) - \gamma(h)$, but the value of ...
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### Non-parametric variogram estimators

I'm working with overdispersed, count spatial data. The goal is to look specifically at spatial dependence patterns. I'm trying to fit variogram models to empirical variograms, however the only ...
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1 vote
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### Lag lengths are larger than my domain in gstat in R? variogram object

My problem is that the my resulting variograms are of a larger lag length than my domain. I have the following code to compute lags in the vertical direction: ...
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