* Item Response Theory Reliability* (

**irtreliability**)

Estimation of reliability coefficients for ability estimates and sum scores from item response theory models as defined in Cheng, Y., Yuan, K.-H. and Liu, C. (2012) <doi:10.1177/0013164411407315> and Kim, S. and Feldt, L. S. (2010) <doi:10.1007/s12564-009-9062-8>. The package supports the 3-PL and generalized partial credit models and includes estimates of the standard errors of the reliability coefficient estimators, derived in Andersson, B. and Xin, T. (2018) <doi:10.1177/0013164417713570>.

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**Unpacking Assignment for Lists via Pattern Matching****dub**)

Provides an operator for assigning nested components of a list to names via a concise, Haskell-like pattern matching syntax. This is especially convenient for assigning individual names to the multiple values that a function may return in the form of a list, and for extracting deeply nested list components.

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**Tools for Cleaning Up Messy Files****thinkr**)

Some tools for cleaning up messy ‘Excel’ files to be suitable for R. People who have been working with ‘Excel’ for years built more or less complicated sheets with names, characters, formats that are not homogeneous. To be able to use them in R nowadays, we built a set of functions that will avoid the majority of importation problems and keep all the data at best.

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**Spatial Entropy Measures****SpatEntropy**)

The heterogeneity of spatial data presenting a finite number of categories can be measured via computation of spatial entropy. Functions are available for the computation of the main entropy and spatial entropy measures in the literature. They include the traditional version of Shannon’s entropy, Batty’s spatial entropy, O’Neill’s entropy, Li and Reynolds’ contagion index, Karlstrom and Ceccato’s entropy, Leibovici’s entropy, Parresol and Edwards’ entropy and Altieri’s entropy. References for all measures can be found under the topic ‘SpatEntropy’. The package is able to work with lattice and point data.

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**Recategorization of Factor Variables by Decision Tree Leaves****tree.bins**)

Provides users the ability to categorize categorical variables dependent on a response variable. It creates a decision tree by using one of the categorical variables (class factor) and the selected response variable. The decision tree is created from the rpart() function from the ‘rpart’ package. The rules from the leaves of the decision tree are extracted, and used to recategorize the appropriate categorical variable (predictor). This step is performed for each of the categorical variables that is fed into the data component of the function. Only variables containing more than 2 factor levels will be considered in the function. The final output generates a data set containing the recategorized variables or a list containing a mapping table for each of the candidate variables. For more details see T. Hastie et al (2009, ISBN: 978-0-387-84857-0).