Estimates model parameters of soil hydraulic property functions by inverting measured data. A wide range of hydraulic models, weighting schemes, global optimization algorithms, Markov chain Monte Carlo samplers, and extended statistical analyses of results are provided. 
	Prediction of soil hydraulic property model parameters and common soil properties using pedotransfer functions is facilitated. Models include the unimodal van Genuchten-Mualem Model (van Genuchten, M.T. (1980) <doi:10.2136/sssaj1980.03615995004400050002x>, Mualem, Y. (1976) <doi:10.1029/WR012i003p00513>),
	the multimodel van Genuchten-Mualem model (Durner, W. (1994) <doi:10.1029/93WR02676> and Priesack, E. and Durner, W. (2006) <doi:10.2136/vzj2005.0066>, as used in Weber, T.K.D., Iden, S.C., and Durner, W. (2017a) <doi:10.1002/2016WR019707>, Weber, T.K.D., Iden, S.C., and Durner, W. (2017b <doi:10.5194/hess-21-6185-2017>),
	the Kosugi 2 parametric-Mualem model (Kosugi, K. (1996) <doi:10.1029/96WR01776>) and the Fredlund-Xing model (Fredlund D.G., and Xing, A. (1994) <doi:10.1139/t94-061>). All models can be extended to account for non-capillary water storage and transport. The isothermal vapour conductivity (Saito, H., Simunek, J. and Mohanty, B.P. (2006) <doi:10.2136/vzj2006.0007>)is calculated based on volumetric air space and 
	a selection of different tortuosity models (Grable, A.R., Siemer, E.G. (1968) <doi:10.2136/sssaj1968.03615995003200020011x>, Lai, S.H., Tiedje J.M., Erickson, E. (1976) <doi:10.2136/sssaj1976.03615995004000010006x>,
	Moldrup, P., Olesen, T., Rolston, D.E., and Yamaguchi, T. (1997) <doi:10.1097/00010694-199709000-00004>, Moldrup, P., Olesen, T., Yoshikawa, S., Komatsu, T., and Rolston, D.E. (2004) <doi:10.2136/sssaj2004.7500>, Moldrup, P., Olesen, T., Yoshikawa, S., Komatsu, T., and Rolston, D.E. (2005) <doi:10.1097/01.ss.0000196768.44165.1f>, Millington, R.J., Quirk, J.P. (1961) <doi:10.1039/TF9615701200>,
	Penman, H.L. (1940) <doi:10.1017/S0021859600048164>, and Xu, X, Nieber, J.L. Gupta, S.C. (1992) <doi:10.2136/sssaj1992.03615995005600060014x>). Parameter estimation is based on identically and independentally distributed (weighted) model residuals (Seber and Wild (2003, ISBN:9780471617600)), and simple model selection criteria (Hoege, M., Woehling, T., and Nowak, W. (2018) <doi:10.1002/2017WR021902>) can be calculated.