# gstools.tools

GStools subpackage providing miscellaneous tools.

## Export

 `vtk_export`(filename, pos, fields[, mesh_type]) Export a field to vtk. `vtk_export_structured`(filename, pos, fields) Export a field to vtk structured rectilinear grid file. `vtk_export_unstructured`(filename, pos, fields) Export a field to vtk unstructured grid file. `to_vtk`(pos, fields[, mesh_type]) Create a VTK/PyVista grid. `to_vtk_structured`(pos, fields) Create a vtk structured rectilinear grid from a field. `to_vtk_unstructured`(pos, fields) Export a field to vtk structured rectilinear grid file.

## Special functions

 `confidence_scaling`([per]) Scaling of standard deviation to get the desired confidence interval. `inc_gamma`(s, x) Calculate the (upper) incomplete gamma function. `inc_gamma_low`(s, x) Calculate the lower incomplete gamma function. `exp_int`(s, x) Calculate the exponential integral . `inc_beta`(a, b, x) Calculate the incomplete Beta function. `tplstable_cor`(r, len_scale, hurst, alpha) Calculate the correlation function of the TPLStable model. `tpl_exp_spec_dens`(k, dim, len_scale, hurst) Spectral density of the TPLExponential covariance model. `tpl_gau_spec_dens`(k, dim, len_scale, hurst) Spectral density of the TPLGaussian covariance model.

## Geometric

 `rotated_main_axes`(dim, angles) Create list of the main axis defined by the given system rotations. `set_angles`(dim, angles) Set the angles for the given dimension. `set_anis`(dim, anis) Set the anisotropy ratios for the given dimension. Calculate number of rotation angles depending on the dimension. Get all 2D sub-planes for rotation. `givens_rotation`(dim, plane, angle) Givens rotation matrix in arbitrary dimensions. `matrix_rotate`(dim, angles) Create a matrix to rotate points to the target coordinate-system. `matrix_derotate`(dim, angles) Create a matrix to derotate points to the initial coordinate-system. `matrix_isotropify`(dim, anis) Create a stretching matrix to make things isotrope. `matrix_anisotropify`(dim, anis) Create a stretching matrix to make things anisotrope. `matrix_isometrize`(dim, angles, anis) Create a matrix to derotate points and make them isotrope. `matrix_anisometrize`(dim, angles, anis) Create a matrix to rotate points and make them anisotrope. `ang2dir`(angles[, dtype, dim]) Convert n-D spherical coordinates to Euclidean direction vectors. Generate grid from a structured position tuple. `generate_st_grid`(pos, time[, mesh_type]) Generate spatio-temporal grid from a position tuple and time array.

## Misc

 `EARTH_RADIUS` earth radius for WGS84 ellipsoid in km