Questions tagged [variogram]
A function describing the degree of spatial dependence of a spatial random field or stochastic process
55 questions
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Creating variograms in a loop in R
I have a data frame of parameters to create variograms of different columns of a geographic dataset. I haven't found a solution yet to make the object argument of the variogram() function dynamic.
...
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Gstat outputs NULL when using variogram() function
I am trying to do a kriging interpolation on a fake data set to familiarize myself with gstat. This code has worked before on a larger df but for some reason when I try to make the variogram, the ...
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Kriging - spatial autocorrelation analysis
I'm reading a paper, where semivariogram analysis was done using kriging to calculate spatial autocorrelation of building hights.
The paper says:
As can be seen from Figure 3, the building in the ...
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Generate simulations using variogram with given mean and standard deviation
I am trying to generate simulations using variogram using the R code below
library(sp)
library(gstat)
library(ggplot2)
library(tidyverse)
library(dplyr)
library(reshape2)
# Call data
points <- ...
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Using a semivariogram to compare different images of the same site
I am writing my master degree thesis.
For my thesis I downloaded images from Copernicus and elaborated them using different methods to obtain images of FVC of some sites.
Now my tutor is asking me to ...
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Generate unconditional simulations with same nugget, sill, and range
I am a newbie with gstat and unconditional simulations. As I understand, unconditional simulations should have the same nugget, psill, and range, but they do not (except nugget) when I use gstat in R. ...
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Ordinary Kriging: "Warning message: In fit.variogram(data.var, vgm("Mat")) : No convergence after 200 iterations: try different initial values?"
I am trying to fit a variogram for kriging using the sp and gstat packages in r, but when I fit the variogram using a mattern fit, I get this warning message:
Warning message:
In fit.variogram(data....
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Geo data normal assumption - effects
I have a basic question regarding Geo data: is the normal assumption mandatory?
Given a dataset I identified outliers and inliers (using Moran local and plot test) so I excluded them from the original ...
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Spatio Temporal Interpolation with gstat in R
I am very new to spatial evaluation and come from psychology.
I am using the software R and the packages "gstat" and "spacetime".
I would like to do a spatio temporal interpolation....
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Geostatistics in SAGA: Strange variogram output
I'm verry new to geostatistic. I'm using variogram to visualize a data (available in .shp here). Then I got the data like this or from this link (updated zip files contains shp, shx, prj, mshp, dbf, ...
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How do I make a variogram of my model residuals in R?
I have a csv file containing LST values for several study sites, canopy cover for each study site, and impervious cover for each study site, and the geographic x/y coordinates for each study site. I ...
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3D variography: rotation matrices for multiple angles support
I'm currently working on a 3D variogram algorithm based on geostatsmodels (which only handles 2D datasets). I'm having a hard time understanding how to have rotation along the z-axis for azimuth ...
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Find spatial and temporal variability from a GeoPandas dataframe of polygons
I have a geopandas dataframe of polygons (all rectangles ~100mx120m) and each of these polygons has an attribute for time and % ice coverage. This is all derived from imagery I collected in the ...
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How do I plot a variogram?
I have a variogram exported from Supervisor which contains (in this case) the Nugget, Sill and Range for two Structures in four directions.
How can I use this as inputs into a plot?
Is there some ...
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Variogram for clustered data point
I would like to study the spatial dependency in my dataset of a variable (crop yield) spread across a country with 250 sites.
A first guess was to use a variogram on the data. However, I am not sure ...
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Variogram fit won't converge
I am having some difficulty fitting a variogram to the data provided at the end of this post. For context, this is baseball data where the x and z coordinates are for the location of the pitch and the ...
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Building Semivariogram/Variogram in QGIS
I am trying to Interpolate Point Data in QGIS using the Ordinary Kriging Modul (SAGA) from the processing menu.
Is it possible to build a Semivariogram in QGIS or call the SAGA Variogramm function ...
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Does the sampling design affect the variogram and mapping? [closed]
I am not sure if this is the right place to ask the question, but I don't know where to ask. So please excuse me if not so.
I am considering two sampling strategies, the first is locating samples on ...
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Which is the model semivariogram for binary data?
I have a binary data (1,0) to calculate spatial distribution of soil bacteria. I have to use indicator kriging (presence/absence) and fitting model of semivariogram. Then, which is the model ...
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Error in calculating covariance matrix and fitting variogram model
When constructing variogram model, usually the spatial points are given, and we build a variogram model and conduct parameter estimation. But here in my question the points are not given while ...
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gstat variogram errors
I am at a complete loss on what I am doing wrong here.
I am trying to build a variogram. No matter what i do i get errors.
My Data:
id lon lat datetime ...
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Cokriging: zero distance cross-semivariance in undersampled cases [gstat error]
Trying to cokrige two variables that are not perfectly colocated (one has sparser measurements than the other), I faced an issue that I'll illustrate with the following MRE.
With the meuse dataset, ...
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Empirical variogram plot in QGIS
I am trying to do kriging on mortality rates using QGIS (I have version 3.0 but I downloaded the 2.18.20 to be able to follow the web documentation and most of the answers here).
From what I have ...
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Preparing dataset to perform co-kriging in R gstat?
This is the first time I'm using co-kriging in gstat. My problem is that I'm not sure how to prepare the data frame to supply to co-kriging when the variable of interest and auxiliary variables are ...
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Kriging with a non-uniform (not space filling with concentrated data in certain regions) sampling design?
I am using Kriging for optimization where local searches are often carried out. However, because of these local searches my sample design becomes poor and my Kriging prediction as well as variance ...
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How to find initial values for fit.variogram
I wish to estimate a variogram for spatially distributed price data in Tanzania. I'm new to both spatial statistics and gstat, and have a couple questions.
(1) I can SEE spatial patterns in price, ...
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How to calculate kriging weights?
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 ...
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semivariogramm - manual calculation
I have a graph with some data points:
From these data points I have created a table and calculated the Euclidean distance for each combination.
Now, I would like to calculate the semi variances ...
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Error in fit.variogram.gls method of gstat package in R
I was trying to fit the variogram parameters of an empirical variogram using GLS (Generalized Least Squares) fitting method. I used the 'fit.variogram.gls' method of the 'gstat' package in R.
I tried ...
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Statistically comparing two spatially congruent continuous rasters?
First: Rasters are the same spatial resolution & extent and contain the same kind of information. Each pixel contains a probability value from 0-1.
Sounds simple to compare. Conventional wisdom ...
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How to obtain nugget parameter from fit.variogram in gstat? [closed]
I have the following code where I fit a variogram using gstat.
vA = variogram(dep_var~elevation=x+y, data, cressie=TRUE)
vmodel = vgm("Sph")
vB = fit.variogram(vA,vmodel)
How can I get the nugget ...
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Fit variogram doesn't work [closed]
I have a variogram and i'm trying to fit an exponential variogram Variogram
and i try to estimate the parameter of this variogram through the data:
vk=variogram(z~1, data=data)
nugget_ini=....
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Fit Variogram Iteration Warning
I would like to perform kriging using a variable call "Secchi.Disk" from a data set I have. However, when fitting the variogram I get the following warming message
Warning message:
In fit.variogram(v,...
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What should be different variogram model in kriging [closed]
In ordinary kriging algorithm in QGIS (Saga algorithms provided in QGIS) there is field for Variogram model which by default is given as 'a + b * x' what does it signify and what are other options to ...
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How to make ordinary krigging with a spherical variogram in SAGA GIS?
I have a very special map to make: it's a sea bird density map. To do this, I interpolate the observation points with ordinary kriging with a variogram. As I've read, the variogram must be of "...
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Poor fit of variograms in spatial GLS models
I run into some problems when investigating correlation structures in spatial GLS models, precisely that fitted variogram does not fit residuals.
Template data can be downloaded here: http://...
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Adjust text font size in plotting autofitvariogram in R?
It should be quite simple to adjust the font size in plotting the outcome ofautofitVariogram using the automap package. The text fonts for the number of pairs are too big; the text fonts for the model,...
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Kriging predictions for presence only data with Maxent
I was doing some geostatistical analysis (variogram+kriging) for a "presence only" type data in a species distribution modeling context. Since, we know that when estimating the (empirical) variogram, ...
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R 'gstat - Warning: singular model in variogram fit
I am trying to perform a kriging interpolation. But when it comes to the point when i want to fit the variogram to the model I get the following warning:
In fit.variogram(vario, vgm("Sph")) : singular ...
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How do I get the fitted values and/or residuals in fit.variogram() function of gstat package of R?
I am trying to do some diagnostics after fitting a variogram model to my empirical variogram using fit.variogram() function in gstat package of R. I need to get a hold of residuals and the fitted ...
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Variogram model - SAGA on QGIS Processing
QGIS 2.14 (Win) comes with SAGA 2.12, which Ordinary Kriging supports 6 variogram model options.
However, if I run SAGA Ordinary Kriging from QGIS Processing Toolbox, there is no drop down menu. Only ...
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Fixing error in if (any(model$range < 0)) statement when fitting variogram in R?
I am using R and trying to fit a variogram model that I created:
mod <- vgm(psill = var(newdfNoNAs$yield_cleaned),range= NA, model = 'Sph',nugget = 0)
And I used
fit_reml <- fit.variogram....
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Ignoring NA values when computing variogram in R?
I am trying to compute a variogram with the R gstat package:
> variogram(yield_cleaned~1, data= newdf)
but it turns out:
Error in .local(obj, ...) : NA values in coordinates
My dataset has ...
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Exponential function variogram sill values
I am using gstat package for deriving a variogram using exponential model.
My R code goes like this:
g <- gstat(id= "HV",formula=HV~X+Y,data=vari)
vari.var <- variogram(g)
vari.var
plot(vari....
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Goodness of fit of variogram model using geoR
How can I find a measure of goodness of fit (let's say an R2) of a model fitted to a variogram by the function variofit using the geoR package?
The only value I have is the "minimised weighted sum of ...
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Creating pooled variogram in gstat
I am currently using gstat to perform ordinary kriging on daily fields of some variable - that is a new variogram is fit for every daily set of observations.
I would like to compare this with ...
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Problem in Variogram Plot [closed]
I tried to plot Variogram by this code from gstat packages:
v <- variogram(log(zinc) ~ 1, meuse)
plot(v)
and here is the output:
But I want to add line to point (draw variogram line).
How I ...
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Interpreting variogram: negative values beyond model sill?
The negative values mean that there is negative autocorrelation at some far distance, like a repulsion. How would this affect assessment of the range?
(This is just for learning the scale of a ...
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semi variogram analysis for buidings in raster dem with penta spherical model
I am carrying out semi-variogram analysis in arcgis using geostatistical tool
on a DEM. the plot gives the semi variance and lag distance. I want to know at what elevation of DEM the sill value is ...
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variogramST in R
I've been following the tutorial in this site to compute the spatio-temporal variogram in R. The result from variogramST is the object called var, and it contains several NAs for np, dist, and gamma, ...
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