interp: Interpolation Methods

Bivariate data interpolation on regular and irregular grids, either linear or using splines are the main part of this package. It is intended to provide FOSS replacement functions for the ACM licensed akima::interp and tripack::tri.mesh functions. Linear interpolation is implemented in interp::interp(..., method="linear"), this corresponds to the call akima::interp(..., linear=TRUE) which is the default setting and covers most of akima::interp use cases in depending packages. A re-implementation of Akimas irregular grid spline interpolation (akima::interp(..., linear=FALSE)) is now also available via interp::interp(..., method="akima"). Estimators for partial derivatives are now also available in interp::locpoly(), these are a prerequisite for the spline interpolation. The basic part is a GPLed triangulation algorithm (sweep hull algorithm by David Sinclair) providing the starting point for the irregular grid interpolator. As side effect this algorithm is also used to provide replacements for almost all functions of the tripack package which also suffers from the same ACM license restrictions. All functions are designed to be backward compatible with their akima / tripack counterparts.

Version: 1.1-6
Depends: R (≥ 3.5.0)
Imports: Rcpp (≥ 0.12.9), deldir
LinkingTo: Rcpp, RcppEigen
Suggests: sp, Deriv, Ryacas, ggplot2, gridExtra, lattice, stringi, stringr, scatterplot3d, MASS
Enhances: RcppEigen
Published: 2024-01-26
DOI: 10.32614/CRAN.package.interp
Author: Albrecht Gebhardt [aut, cre, cph], Roger Bivand [aut], David Sinclair [aut, cph] (author of the shull library)
Maintainer: Albrecht Gebhardt <albrecht.gebhardt at>
License: GPL-2 | GPL-3 [expanded from: GPL (≥ 2)]
NeedsCompilation: yes
Materials: README
In views: NumericalMathematics, Spatial
CRAN checks: interp results


Reference manual: interp.pdf
Vignettes: Interpolation
Local polynomial regression in two variables applied to estimating partial derivatives
Triangulation of irregular spaced data


Package source: interp_1.1-6.tar.gz
Windows binaries: r-devel:, r-release:, r-oldrel:
macOS binaries: r-release (arm64): interp_1.1-6.tgz, r-oldrel (arm64): interp_1.1-6.tgz, r-release (x86_64): interp_1.1-6.tgz, r-oldrel (x86_64): interp_1.1-6.tgz
Old sources: interp archive

Reverse dependencies:

Reverse depends: contourPlot
Reverse imports: alphahull, BayesX, cassowaryr, edgebundle, EvolutionaryGames, FieldSimR, ggtreeSpace, GPFDA, latticeExtra, Luminescence, multiocc, OCplus, OUwie, pcds, pcds.ugraph, quollr, RCarb, SharkDemography, SOMbrero, spikeSlabGAM, spreval, stpphawkes, survSens, TCIU, vprr
Reverse suggests: adegenet, bamlss, bandle, bmstdr, broom, deepgp, DPQ, DSSP, dynaTree, evd, fBasics, fdasrvf, flipr, gam, geometry, ggformula, insight, isopleuros, laGP, locfit, oce, ParamHelpers, plgp, pre, quantreg, R2BayesX, r5r, randomForestSRC, rgl, rpanel, shotGroups, sm, vegdata


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