R Statistics: Difference between revisions
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==What is R?== | ==What is R?== | ||
R is a system for statistical analyses and graphics created by Ross Ihaka | R is a system for statistical analyses and graphics created by Ross Ihaka | ||
and Robert Gentleman1. R is both a software and a language considered as a | and Robert Gentleman1. R is both a software and a language considered as a | ||
dialect of the S language created by the AT&T Bell Laboratories. S is available | dialect of the S language created by the AT&T Bell Laboratories. S is available | ||
as the software S-PLUS commercialized by Insightful2. There are important | as the software S-PLUS commercialized by Insightful2. There are important | ||
erences in the designs of R and of S: those who want to know more on this | |||
point can read the paper by Ihaka & Gentleman (1996) or the R-FAQ3, a copy | point can read the paper by Ihaka & Gentleman (1996) or the R-FAQ3, a copy | ||
of which is also distributed with R. | of which is also distributed with R. | ||
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its development and distribution are carried out by several statisticians known | its development and distribution are carried out by several statisticians known | ||
as the R Development Core Team. | as the R Development Core Team. | ||
R is available in several forms: the sources (written mainly in C and | R is available in several forms: the sources (written mainly in C and | ||
some routines in Fortran), essentially for Unix and Linux machines, or some | some routines in Fortran), essentially for Unix and Linux machines, or some | ||
pre-compiled binaries for Windows, Linux, and Macintosh. The | pre-compiled binaries for Windows, Linux, and Macintosh. The les needed | ||
to install R, either from the sources or from the pre-compiled binaries, are | to install R, either from the sources or from the pre-compiled binaries, are | ||
distributed from the internet site of the Comprehensive R Archive Network | distributed from the internet site of the Comprehensive R Archive Network | ||
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the distributions of Linux (Debian, . . . ), the binaries are generally | the distributions of Linux (Debian, . . . ), the binaries are generally | ||
available for the most recent versions; look at the CRAN site if necessary. | available for the most recent versions; look at the CRAN site if necessary. | ||
R has many functions for statistical analyses and graphics; the latter are | R has many functions for statistical analyses and graphics; the latter are | ||
visualized immediately in their own window and can be saved in various formats | visualized immediately in their own window and can be saved in various formats | ||
(jpg, png, bmp, ps, pdf, emf, pictex, | (jpg, png, bmp, ps, pdf, emf, pictex, xg; the available formats may | ||
depend on the operating system). The results from a statistical analysis are | depend on the operating system). The results from a statistical analysis are | ||
displayed on the screen, some intermediate results (P-values, regression coef- | displayed on the screen, some intermediate results (P-values, regression coef- | ||
cients, residuals, . . . ) can be saved, written in a le, or used in subsequent | |||
analyses. | analyses. | ||
The R language allows the user, for instance, to program loops to successively | The R language allows the user, for instance, to program loops to successively | ||
analyse several data sets. It is also possible to combine in a single | analyse several data sets. It is also possible to combine in a single | ||
erent statistical functions to perform more complex analyses. The | |||
R users may benet from a large number of programs written for S and available | |||
R users may | |||
on the internet6, most of these programs can be used directly with R. | on the internet6, most of these programs can be used directly with R. | ||
At | At rst, R could seem too complex for a non-specialist. This may not | ||
be true actually. In fact, a prominent feature of R is its | be true actually. In fact, a prominent feature of R is its | ||
exibility. Whereas | exibility. Whereas a classical software displays immediately the results of an analysis, R stores | ||
a classical software displays immediately the results of an analysis, R stores | |||
these results in an \object", so that an analysis can be done with no result | these results in an \object", so that an analysis can be done with no result | ||
displayed. The user may be surprised by this, but such a feature is very useful. | displayed. The user may be surprised by this, but such a feature is very useful. | ||
Indeed, the user can extract only the part of the results which is of interest. | Indeed, the user can extract only the part of the results which is of interest. | ||
==Download and Install R== | ==Download and Install R== | ||
Revision as of 06:57, 20 June 2006
R for Statiscal Computing
What is R?
R is a system for statistical analyses and graphics created by Ross Ihaka and Robert Gentleman1. R is both a software and a language considered as a dialect of the S language created by the AT&T Bell Laboratories. S is available as the software S-PLUS commercialized by Insightful2. There are important erences in the designs of R and of S: those who want to know more on this point can read the paper by Ihaka & Gentleman (1996) or the R-FAQ3, a copy of which is also distributed with R. R is freely distributed under the terms of the GNU General Public Licence4; its development and distribution are carried out by several statisticians known as the R Development Core Team.
R is available in several forms: the sources (written mainly in C and some routines in Fortran), essentially for Unix and Linux machines, or some pre-compiled binaries for Windows, Linux, and Macintosh. The les needed to install R, either from the sources or from the pre-compiled binaries, are distributed from the internet site of the Comprehensive R Archive Network (CRAN)5 where the instructions for the installation are also available. Regarding the distributions of Linux (Debian, . . . ), the binaries are generally available for the most recent versions; look at the CRAN site if necessary.
R has many functions for statistical analyses and graphics; the latter are visualized immediately in their own window and can be saved in various formats (jpg, png, bmp, ps, pdf, emf, pictex, xg; the available formats may depend on the operating system). The results from a statistical analysis are displayed on the screen, some intermediate results (P-values, regression coef- cients, residuals, . . . ) can be saved, written in a le, or used in subsequent analyses.
The R language allows the user, for instance, to program loops to successively analyse several data sets. It is also possible to combine in a single erent statistical functions to perform more complex analyses. The
R users may benet from a large number of programs written for S and available on the internet6, most of these programs can be used directly with R. At rst, R could seem too complex for a non-specialist. This may not be true actually. In fact, a prominent feature of R is its exibility. Whereas a classical software displays immediately the results of an analysis, R stores these results in an \object", so that an analysis can be done with no result displayed. The user may be surprised by this, but such a feature is very useful. Indeed, the user can extract only the part of the results which is of interest.
