R-project – Statistical computing

R provides a wide variety of statistical techniques such as linear and nonlinear modeling, classical statistical tests, time-series analysis, classification and clustering. The R environment is an integrated suite of software facilities for data manipulation, calculation and graphical display. It includes:

• An effective data handling and storage facility.

• A suite of operators for calculations on arrays.

• A large, coherent, integrated collection of intermediate tools for data analysis.

• Graphical facilities for data analysis and display.

• A well-developed, simple and effective programming language which includes conditionals, loops, user-defined recursive functions and input and output facilities.

R is a fully planned and coherent system. R, like S, is designed around a computer language, and it allows users to add additional functionality by defining new functions. R can be extended via packages. There are about eight packages supplied with the R distribution and many more are available through the CRAN family of Internet sites covering a very wide range of modern statistics.

Much of the system is written in the R dialect of S, which makes it easy for users to follow the algorithmic choices made. For computationally-intensive tasks, C, C++ and Fortran code can be linked and called at run time. Advanced users can write C code to manipulate R objects directly. It compiles and runs on a wide variety of operative systems such as FreeBSD, Linux, Windows and MacOS.