S is a statistical programming language developed primarily by John Chambers and (in earlier versions) Rick Becker and Allan Wilks of Bell Laboratories. The purpose of language, as John Chambers put it, is “to turn ideas into software, quickly and precisely”.
The modern implementation of S is R, part of the GNU free software project. S-PLUS, a commercial product, previously sold by TIBCO Software
S is one of several statistical computing languages designed at Bell Laboratories. It was first created between 1975–1976. Until then, most statistical computing was calling the Fortran subroutines. However, S was designed to offer an alternative and more interactive approach. It is motivated in part by the exploratory data analysis advocated by John Tukey. Early design decisions that apply even today include interactive graphics devices (printers and character terminals at the time). It providing easily accessible documentation for the functionality.
First S Language
The first working version of the S was built in 1976, and operated on the GCOS operating system. Currently, S is unnamed, and suggestions include ISCS (Interactive SCS), SCS (Statistical Computing System), and SAS (Statistical Analysis System) (which has already been taken: see SAS Systems). The name ‘S’ (used with single quotes until 1979) was chosen, as it was a common letter in suggestions and consistent with other programming languages designed from the same institution at the time (namely the C programming language).
When UNIX/32V was ported to the (new) 32-bit DEC VAX, computing on the Unix platform became S-worthy. In late 1979, S was ported from GCOS to UNIX, which would become the new mainstream platform.
Then, in 1980 the first version of the S was outside Bell Laboratories and in 1981 the source version was made available. In 1984 two books were published by the research team at Bell Laboratories: S: An Interactive Environment for Data Analysis and Graphics (1984 Brown Book) and Extending the S System. Also, in 1984 the source code for the S was licensed through AT&T Software Sales for educational and commercial purposes.
“new S” Language
In 1988, many changes were made to S and the syntax of the language. The New S Language (1988 Blue Book) is introduce new features. Such as the transition from macros to functions and how functions can be passed to other functions (as applicable). Many other changes to the S language were to extend the concept of “objects”, and to make the syntax more consistent (and strict). However, many users find the transition to New S difficult, as their macros need to write. Many other changes to S, such as the use of X11 and PostScript graphics tools, the rewriting of many internal functions from Fortran to C. The use of (only) double-precision arithmetic. The New S language is very similar to that used in modern versions of S-PLUS and R.
In 1991, Statistical Models in S (1991 White Book) was published, which introduced the use of formula notation (which uses the ~ operator), dataframe objects, and modified use of object and class methods.
The latest version of the S standard is S4, released in 1998. It provides advanced object-oriented features. The S4 class is very different from the S3 class. S4 formally defines representation and inheritance for each class. Generic functions to methods based on class from any number of arguments instead of just one.
The counterclockwise direction is the S configuration (spooky, Latin for left). The clockwise is the R configuration (rectus, Latin for right). According to atomic number when only atoms are present and in a group of atoms by atomic number.