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# variogramfit 1.0

Date Added: June 04, 2013  |  Visits: 235

variogramfit performs a least squares fit of various theoretical variograms to an experimental, isotropic variogram. The user can choose between various bounded (e.g. spherical) and unbounded (e.g. exponential) models. A nugget variance can be modelled as well, but higher nested models are not supported.The function works best with the function fminsearchbnd available on the FEX. You should download it from the File Exchange (File ID: #8277). If you don't have fminsearchbnd, variogramfit uses fminsearch. The problem with fminsearch is, that it might return negative variances or ranges.Supported bounded models:'blinear' -- bounded linear'circular' -- circular model'spherical' -- spherical model, =default'pentaspherical' -- pentaspherical modelSupported unbounded functions :'exponential' -- exponential model'gaussian' -- gaussian variogram'whittle' -- Whittle's elementary correlation (involves a modified Bessel function of the second kind).'stable' -- stable models sensu Wackernagel 1995). Same as gaussian, but with different exponents. Supply the exponent alpha ( 0, default = 1). Note that for particular values of nu the matern model reduces to other authorized variogram models. (nu = 0.5 : exponential model, nu = 1 : Whittles model, nu -> inf : Gaussian model)References:Wackernagel, H. (1995): Multivariate Geostatistics, Springer.Webster, R., Oliver, M. (2001): Geostatistics for Environmental Scientists. Wiley & Sons.Minsasny, B., McBratney, A. B. (2005): The MatdoTern function as general model for soil variograms. Geoderma, 3-4, 192-207.

 Requirements: No special requirements Platforms: Matlab Keyword: 1995 Same,  2005 The,  3d 05,  8277 If,  Additional Pnpv,  Additional Pnpvpair,  As Well,  Authorized Variogram,  Ddefault Pentaspherical Pentaspherical,  Exponential,  Gaussian,  General,  Geostatistics,  Matern,  Matern Matern,  Multivariate,  Sonsminsasny Users rating: 0/10