All notable changes to GSTools will be documented in this file.

1.3.0 - Pure Pink - 2021-04


Geographical Coordinates Support (#113)

  • added boolean init parameter latlon to indicate a geographic model. When given, spatial dimension is fixed to dim=3, anis and angles will be ignored, since anisotropy is not well-defined on a sphere.

  • add property field_dim to indicate the dimension of the resulting field. Will be 2 if latlon=True

  • added yadrenko variogram, covariance and correlation method, since the geographic models are derived from standard models in 3D by plugging in the chordal distance of two points on a sphere derived from there great-circle distance zeta:

    • vario_yadrenko: given by variogram(2 * np.sin(zeta / 2))

    • cov_yadrenko: given by covariance(2 * np.sin(zeta / 2))

    • cor_yadrenko: given by correlation(2 * np.sin(zeta / 2))

  • added plotting routines for yadrenko methods described above

  • the isometrize and anisometrize methods will convert latlon tuples (given in degree) to points on the unit-sphere in 3D and vice versa

  • representation of geographical models don’t display the dim, anis and angles parameters, but latlon=True

  • fit_variogram will expect an estimated variogram with great-circle distances given in radians

  • Variogram estimation

    • latlon switch implemented in estimate_vario routine

    • will return a variogram estimated by the great-circle distance (haversine formula) given in radians

  • Field

    • added plotting routines for latlon fields

    • no vector fields possible on latlon fields

    • corretly handle pos tuple for latlon fields

Krige Unification (#97)

  • Swiss Army Knife for kriging: The Krige class now provides everything in one place

  • “Kriging the mean” is now possible with the switch only_mean in the call routine

  • Simple/Ordinary/Universal/ExtDrift/Detrended are only shortcuts to Krige with limited input parameter list

  • We now use the covariance function to build up the kriging matrix (instead of variogram)

  • An unbiased switch was added to enable simple kriging (where the unbiased condition is not given)

  • An exact switch was added to allow smother results, if a nugget is present in the model

  • An cond_err parameter was added, where measurement error variances can be given for each conditional point

  • pseudo-inverse matrix is now used to solve the kriging system (can be disabled by the new switch pseudo_inv), this is equal to solving the system with least-squares and prevents numerical errors

  • added options fit_normalizer and fit_variogram to automatically fit normalizer and variogram to given data

Directional Variograms and Auto-binning (#87, #106, #131)

  • new routine name vario_estimate instead of vario_estimate_unstructured (old kept for legacy code) for simplicity

  • new routine name vario_estimate_axis instead of vario_estimate_structured (old kept for legacy code) for simplicity

  • vario_estimate

    • added simple automatic binning routine to determine bins from given data (one third of box diameter as max bin distance, sturges rule for number of bins)

    • allow to pass multiple fields for joint variogram estimation (e.g. for daily precipitation) on same mesh

    • no_data option added to allow missing values

    • masked fields

      • user can now pass a masked array (or a list of masked arrays) to deselect data points.

      • in addition, a mask keyword was added to provide an external mask

    • directional variograms

      • diretional variograms can now be estimated

      • either provide a list of direction vectors or angles for directions (spherical coordinates)

      • can be controlled by given angle tolerance and (optional) bandwidth

      • prepared for nD

    • structured fields (pos tuple describes axes) can now be passed to estimate an isotropic or directional variogram

    • distance calculation in cython routines in now independent of dimension

  • vario_estimate_axis

    • estimation along array axis now possible in arbitrary dimensions

    • no_data option added to allow missing values (sovles #83)

    • axis can be given by name ("x", "y", "z") or axis number (0, 1, 2, 3, …)

Better Variogram fitting (#78, #145)

  • fixing sill possible now

  • loss is now selectable for smoother handling of outliers

  • r2 score can now be returned to get an impression of the goodness of fitting

  • weights can be passed

  • instead of deselecting parameters, one can also give fix values for each parameter

  • default init guess for len_scale is now mean of given bin-centers

  • default init guess for var and nugget is now mean of given variogram values

CovModel update (#109, #122, #157)

  • add new rescale argument and attribute to the CovModel class to be able to rescale the len_scale (usefull for unit conversion or rescaling len_scale to coincide with the integral_scale like it’s the case with the Gaussian model) See: #90, GeoStat-Framework/PyKrige#119

  • added new len_rescaled attribute to the CovModel class, which is the rescaled len_scale: len_rescaled = len_scale / rescale

  • new method default_rescale to provide default rescale factor (can be overridden)

  • remove doctest calls

  • docstring updates in CovModel and derived models

  • updated all models to use the cor routine and make use of the rescale argument (See: #90)

  • TPL models got a separate base class to not repeat code

  • added new models (See: #88):

    • HyperSpherical: (Replaces the old Intersection model) Derived from the intersection of hyper-spheres in arbitrary dimensions. Coincides with the linear model in 1D, the circular model in 2D and the classical spherical model in 3D

    • SuperSpherical: like the HyperSpherical, but the shape parameter derived from dimension can be set by the user. Coincides with the HyperSpherical model by default

    • JBessel: a hole model valid in all dimensions. The shape parameter controls the dimension it was derived from. For nu=0.5 this model coincides with the well known wave hole model.

    • TPLSimple: a simple truncated power law controlled by a shape parameter nu. Coincides with the truncated linear model for nu=1

    • Cubic: to be compatible with scikit-gstat in the future

  • all arguments are now stored as float internally (#157)

  • string representation of the CovModel class is now using a float precision (CovModel._prec=3) to truncate longish output

  • string representation of the CovModel class now only shows anis and angles if model is anisotropic resp. rotated

  • dimension validity check: raise a warning, if given model is not valid in the desired dimension (See: #86)

Normalizer, Trend and Mean (#124)

  • new normalize submodule containing power-transforms for data to gain normality

  • Base-Class: Normalizer providing basic functionality including maximum likelihood fitting

  • added: LogNormal, BoxCox, BoxCoxShift, YeoJohnson, Modulus and Manly

  • normalizer, trend and mean can be passed to SRF, Krige and variogram estimation routines

    • A trend can be a callable function, that represents a trend in input data. For example a linear decrease of temperature with height.

    • The normalizer will be applied after the data was detrended, i.e. the trend was substracted from the data, in order to gain normality.

    • The mean is now interpreted as the mean of the normalized data. The user could also provide a callable mean, but it is mostly meant to be constant.

Arbitrary dimensions (#112)

  • allow arbitrary dimensions in all routines (CovModel, Krige, SRF, variogram)

  • anisotropy and rotation following a generalization of tait-bryan angles

  • CovModel provides isometrize and anisometrize routines to convert points

New Class for Conditioned Random Fields (#130)


  • CondSRF replaces the conditioning feature of the SRF class, which was cumbersome and limited to Ordinary and Simple kriging

  • CondSRF behaves similar to the SRF class, but instead of a covariance model, it takes a kriging class as input. With this kriging class, all conditioning related settings are defined.


  • Python 3.9 Support #107

  • add routines to format struct. pos tuple by given dim or shape

  • add routine to format struct. pos tuple by given shape (variogram helper)

  • remove subpackage

  • support meshio>=4.0 and add as dependency

  • PyVista mesh support #59

  • added EARTH_RADIUS as constant providing earths radius in km (can be used to rescale models)

  • add routines latlon2pos and pos2latlon to convert lat-lon coordinates to points on unit-sphere and vice versa

  • a lot of new examples and tutorials

  • RandMeth class got a switch to select the sampling strategy

  • plotter for n-D fields added #141

  • antialias for contour plots of 2D fields #141

  • building from source is now configured with pyproject.toml to care about build dependencies, see #154


  • drop support for Python 3.5 #146

  • added a finit limit for shape-parameters in some CovModels #147

  • drop usage of pos2xyz and xyz2pos

  • remove structured option from generators (structured pos need to be converted first)

  • explicitly assert dim=2,3 when generating vector fields

  • simplify pre_pos routine to save pos tuple and reformat it an unstructured tuple

  • simplify field shaping

  • simplify plotting routines

  • only the "unstructured" keyword is recognized everywhere, everything else is interpreted as "structured" (e.g. "rectilinear")

  • use GitHub-Actions instead of TravisCI

  • parallel build now controlled by env-var GSTOOLS_BUILD_PARALLEL=1, see #154

  • install extra target for [dev] dropped, can be reproduced by pip install gstools[test, doc], see #154


  • typo in keyword argument for vario_estimate_structured #80

  • isotropic rotation of SRF was not possible #100

  • CovModel.opt_arg now sorted #103

  • check if weights are given as a string (numpy comparison error) #111

  • several pylint fixes (#159)

1.2.1 - Volatile Violet - 2020-04-14


  • ModuleNotFoundError is not present in py35

  • Fixing Cressie-Bug #76

  • Adding analytical formula for integral scales of rational and stable model

  • remove prange from IncomprRandMeth summators to prevent errors on Win and macOS

1.2.0 - Volatile Violet - 2020-03-20


  • different variogram estimator functions can now be used #51

  • the TPLGaussian and TPLExponential now have analytical spectra #67

  • added property is_isotropic to CovModel #67

  • reworked the whole krige sub-module to provide multiple kriging methods #67

    • Simple

    • Ordinary

    • Universal

    • External Drift Kriging

    • Detrended Kriging

  • a new transformation function for discrete fields has been added #70

  • reworked tutorial section in the documentation #63

  • pyvista interface #29


  • Python versions 2.7 and 3.4 are no longer supported #40 #43

  • CovModel: in 3D the input of anisotropy is now treated slightly different: #67

    • single given anisotropy value [e] is converted to [1, e] (it was [e, e] before)

    • two given length-scales [l_1, l_2] are converted to [l_1, l_2, l_2] (it was [l_1, l_2, l_1] before)


  • a race condition in the structured variogram estimation has been fixed #51

1.1.1 - Reverberating Red - 2019-11-08



  • deprecation warnings are now printed if Python versions 2.7 or 3.4 are used #40 #41


1.1.0 - Reverberating Red - 2019-10-01


  • by using Cython for all the heavy computations, we could achieve quite some speed ups and reduce the memory consumption significantly #16

  • parallel computation in Cython is now supported with the help of OpenMP and the performance increase is nearly linear with increasing cores #16

  • new submodule krige providing simple (known mean) and ordinary (estimated mean) kriging working analogous to the srf class

  • interface to pykrige to use the gstools CovModel with the pykrige routines (

  • the srf class now provides a plot and a vtk_export routine

  • incompressible flow fields can now be generated #14

  • new submodule providing several field transformations like: Zinn&Harvey, log-normal, bimodal, … #13

  • Python 3.4 and 3.7 wheel support #19

  • field can now be generated directly on meshes from meshio and ogs5py, see: commit f4a3439

  • the srf and kriging classes now store the last pos, mesh_type and field values to keep them accessible, see: commit 29f7f1b

  • tutorials on all important features of GSTools have been written for you guys #20

  • a new interface to pyvista is provided to export fields to python vtk representation, which can be used for plotting, exploring and exporting fields #29


  • the license was changed from GPL to LGPL in order to promote the use of this library #25

  • the rotation angles are now interpreted in positive direction (counter clock wise)

  • the force_moments keyword was removed from the SRF call method, it is now in provided as a field transformation #13

  • drop support of python implementations of the variogram estimators #18

  • the variogram_normed method was removed from the CovModel class due to redundance commit 25b1647

  • the position vector of 1D fields does not have to be provided in a list-like object with length 1 commit a6f5be8


  • several minor bugfixes

1.0.1 - Bouncy Blue - 2019-01-18


  • fixed Numpy and Cython version during build process

1.0.0 - Bouncy Blue - 2019-01-16


  • added a new covariance class, which allows the easy usage of arbitrary covariance models

  • added many predefined covariance models, including truncated power law models

  • added tutorials and examples, showing and explaining the main features of GSTools

  • variogram models can be fitted to data

  • prebuilt binaries for many Linux distributions, Mac OS and Windows, making the installation, especially of the Cython code, much easier

  • the generated fields can now easily be exported to vtk files

  • variance scaling is supported for coarser grids

  • added pure Python versions of the variogram estimators, in case somebody has problems compiling Cython code

  • the documentation is now a lot cleaner and easier to use

  • the code is a lot cleaner and more consistent now

  • unit tests are now automatically tested when new code is pushed

  • test coverage of code is shown

  • GeoStat Framework now has a website, visit us:


  • release is not downwards compatible with release v0.4.0

  • SRF creation has been adapted for the CovModel

  • a tuple pos is now used instead of x, y, and z for the axes

  • renamed estimate_unstructured and estimate_structured to vario_estimate_unstructured and vario_estimate_structured for less ambiguity


  • several minor bugfixes

0.4.0 - Glorious Green - 2018-07-17


  • import of cython functions put into a try-block

0.3.6 - Original Orange - 2018-07-17

First release of GSTools.