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Numbers

Numerical values and vectors of numerical values can be of type double, complex or integer. There is no single precision data type. The default type is double.

Exponential notation can be used to represent numbers; e.g. x <- 1.0e10; assigns the value 1.0x10¹⁰ to x.

Predefined values

pi     ratio of circumference of a circle to its diameter 
1i     unit imaginary value
NA     a logical constant indicating a missing value. 
Inf    representation of `infinity'.
NaN    representation of `Not a Number'.

Complex numbers

The complex component of a complex number can be specifed by Xi, where X is a floating point value. For example,
sqrt(-1) is represented as

1i

This is the numeric value one followed by the letter i. In order to get the standard mathematical functions to produce complex results, one must specify the argument as a complex quantity. For example, to compute the complex value sqrt(-1) requires

> sqrt(-1.0 + 0i);
[1] 0+1i

To change the maximal number of digits that are displayed when numbers are printed use the command

options(digits=XXX);

where XXX is the number of digits desired.

Use Machine() to display the characteristics of the numbers used to store double, integers etc.

See Also : Displaying/Saving Results

Original Documentation : double, complex, integer, Inf, NAN, NA, Machine, options

Samples

# Printing out 10 digits of the the internal value of pi

  options(digits = 10)
  pi
  [1] 3.141592654

# Evaluating the sqrt(-1)

  sqrt(-1.0 + 0.0i)
  [1] 0+1i

# Evaluating the complex exponential of i

  exp(1i)
  [1] 0.5403023+0.841471i

# NA's (not assigned's) are the default value when an array is resized and new values are introduced ...

 z <- double();
 z[3] <- 3.0
 z
 [1] NA NA  3

# Generate Inf and NaN's

  1.0/0.0
  [1] Inf

  0.0/0.0
  [1] NaN

  sqrt(-1.0)
  [1] NaN
  Warning message: 
  NaNs produced in: sqrt(-1)