Arithmetic
Arithmetic Operators

### Description

The arithmetic operations of addition, subtraction, multiplication, division, exponentiation, integer division, and modulo. All except integer division and modulo accept both complex and numeric arguments. Integer division and modulo accept only numeric arguments.

### Usage

    e1 op e2

### Arguments

op | +, -, *, /, ^, %/% or %%. +, -, * and / are the usual arithmetic operators. ^ is exponentiation. %/% is integer division. %% is modulo. Integer division (%/%) and modulo (%%) always satisfy e1==(e1%/%e2)*e2+e1%%e2.
e1,e2 | numeric or complex. Missing values (NAs) are allowed. For both integer divison and modulo, the operands must be numeric.

### Details

Section 5.6.1 of Becker, Chambers and Wilks describes the rules for dealing with operands possessing attributes. Also see section 5.1.5 for details on domains and branch cuts in the case of complex arguments for exponentiation.
These are generic functions, because they are part of the "Arith" group within the "Ops" group. Group methods exist for data frames. They also exist for factors and ordered factors, but arithmetic is not allowed for these classes.
Zero-length operands in arithmetic operations force zero-length results. That is, numeric(0) + anything yields numeric(0).
Value

+, -, *, /, and ^ (arithmetic functions) | returns a numeric or complex result, with the shorter argument used cyclically if necessary.
%/% (integer division) | if e2!=0, returns floor(e1/e2). If e2==0, and if e1 is an integer, returns 0. Otherwise, returns Inf.
%% (modulo) | returns e1-floor(e1/e2)*e2. (See Knuth, 1968, section 1.2.4.).

Classes
This function is used as the default method for classes that do not inherit a specific method for the function or for the Ops group of functions. The result retains the class and the attributes. If this behavior is not appropriate, the designer of the class should provide a method for the function or for the Ops group.
References
Knuth, D. E. (1968). The Art of Computer Programming, Volume 1: Fundamental Algorithms
Addison-Wesley, Reading, Mass.
Becker, R.A., Chambers, J.M., and Wilks, A.R. (1989). The New S Language Wadsworth, Belmont, CA.
See Also
Arith, Matrix-product, Complex, cumsum, exp.
Examples

    x=runif(10)
    x-mean(x)  # deviations from the mean; second argument used repeatedly
    (1+(5:8)/1200)^12     # compound interest, 5:8 per annum monthly
    get("%/%") # print the definition

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