R Data Structure

An R Data Structure is a data structure that is expressed in as R code.

• Context:
  • It can be associated to zero or more R Data Items.
  • It can defined by an R DDL Statement (within the R programming language).
  • It can accessed by an R DAL Statement (within the R programming language).
  • It can have an R Data Structure Class, an R Data Structure Mode, and one or more R Data Structure Attributes.
  • It can contain R Missing Values if(length(which (is.na(data_structure) )) > 0) {print "ds has missing values"}
  • It can (typically) be accessed by an R program.
• Example(s):
  • an R Vector Structure, for R Vectors.
  • a R Array Structure, for R Arrays.
  • a R Hash Structure.
• Counter-Example(s):
  • a Python Data Structure, Perl data structure, Scala data structure, SQL data structure.
• See: R Statement, R c() Function.

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References

2012

• http://cran.r-project.org/doc/manuals/R-intro.html#Vectors-and-assignment
  • R operates on named data structures. The simplest such structure is the numeric vector, which is a single entity consisting of an ordered collection of numbers. To set up a vector named x, say, consisting of five numbers, namely 10.4, 5.6, 3.1, 6.4 and 21.7, use the R command

    > x <- c(10.4, 5.6, 3.1, 6.4, 21.7)

    This is an assignment statement using the function c() which in this context can take an arbitrary number of vector arguments and whose value is a vector got by concatenating its arguments end to end.6

    A number occurring by itself in an expression is taken as a vector of length one.

• http://genomics.jhu.edu/modules/genRmod006.html
  • R objects can be of different class and mode, and can have a distinct set of attributes.

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