(octave.info)Mathematical Constants


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17.9 Mathematical Constants
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 -- : e
 -- : e (N)
 -- : e (N, M)
 -- : e (N, M, K, ...)
 -- : e (..., CLASS)
     Return a scalar, matrix, or N-dimensional array whose elements are
     all equal to the base of natural logarithms.

     The constant ‘e’ satisfies the equation ‘log’ (e) = 1.

     When called with no arguments, return a scalar with the value e.

     When called with a single argument, return a square matrix with the
     dimension specified.

     When called with more than one scalar argument the first two
     arguments are taken as the number of rows and columns and any
     further arguments specify additional matrix dimensions.

     The optional argument CLASS specifies the return type and may be
     either "double" or "single".

     See also: Note: log, Note: exp, Note: pi,
     Note: I.

 -- : pi
 -- : pi (N)
 -- : pi (N, M)
 -- : pi (N, M, K, ...)
 -- : pi (..., CLASS)
     Return a scalar, matrix, or N-dimensional array whose elements are
     all equal to the ratio of the circumference of a circle to its
     diameter.

     Internally, ‘pi’ is computed as ‘4.0 * atan (1.0)’.

     When called with no arguments, return a scalar with the value of
     pi.

     When called with a single argument, return a square matrix with the
     dimension specified.

     When called with more than one scalar argument the first two
     arguments are taken as the number of rows and columns and any
     further arguments specify additional matrix dimensions.

     The optional argument CLASS specifies the return type and may be
     either "double" or "single".

     See also: Note: e, Note: I.

 -- : I
 -- : I (N)
 -- : I (N, M)
 -- : I (N, M, K, ...)
 -- : I (..., CLASS)
     Return a scalar, matrix, or N-dimensional array whose elements are
     all equal to the pure imaginary unit, defined as ‘sqrt (-1)’.

     I, and its equivalents i, j, and J, are functions so any of the
     names may be reused for other purposes (such as i for a counter
     variable).

     When called with no arguments, return a scalar with the value i.

     When called with a single argument, return a square matrix with the
     dimension specified.

     When called with more than one scalar argument the first two
     arguments are taken as the number of rows and columns and any
     further arguments specify additional matrix dimensions.

     The optional argument CLASS specifies the return type and may be
     either "double" or "single".

     See also: Note: e, Note: pi, Note: log,
     Note: exp.

 -- : Inf
 -- : Inf (N)
 -- : Inf (N, M)
 -- : Inf (N, M, K, ...)
 -- : Inf (..., CLASS)
     Return a scalar, matrix or N-dimensional array whose elements are
     all equal to the IEEE representation for positive infinity.

     Infinity is produced when results are too large to be represented
     using the IEEE floating point format for numbers.  Two common
     examples which produce infinity are division by zero and overflow.

          [ 1/0 e^800 ]
          ⇒ Inf   Inf

     When called with no arguments, return a scalar with the value
     ‘Inf’.

     When called with a single argument, return a square matrix with the
     dimension specified.

     When called with more than one scalar argument the first two
     arguments are taken as the number of rows and columns and any
     further arguments specify additional matrix dimensions.

     The optional argument CLASS specifies the return type and may be
     either "double" or "single".

     See also: Note: isinf, Note: NaN.

 -- : NaN
 -- : NaN (N)
 -- : NaN (N, M)
 -- : NaN (N, M, K, ...)
 -- : NaN (..., CLASS)
     Return a scalar, matrix, or N-dimensional array whose elements are
     all equal to the IEEE symbol NaN (Not a Number).

     NaN is the result of operations which do not produce a well defined
     numerical result.  Common operations which produce a NaN are
     arithmetic with infinity (Inf - Inf), zero divided by zero (0/0),
     and any operation involving another NaN value (5 + NaN).

     Note that NaN always compares not equal to NaN (NaN != NaN). This
     behavior is specified by the IEEE standard for floating point
     arithmetic.  To find NaN values, use the ‘isnan’ function.

     When called with no arguments, return a scalar with the value
     ‘NaN’.

     When called with a single argument, return a square matrix with the
     dimension specified.

     When called with more than one scalar argument the first two
     arguments are taken as the number of rows and columns and any
     further arguments specify additional matrix dimensions.

     The optional argument CLASS specifies the return type and may be
     either "double" or "single".

     See also: Note: isnan, Note: Inf.

 -- : eps
 -- : eps (X)
 -- : eps (N, M)
 -- : eps (N, M, K, ...)
 -- : eps (..., CLASS)
     Return a scalar, matrix or N-dimensional array whose elements are
     all eps, the machine precision.

     More precisely, ‘eps’ is the relative spacing between any two
     adjacent numbers in the machine’s floating point system.  This
     number is obviously system dependent.  On machines that support
     IEEE floating point arithmetic, ‘eps’ is approximately 2.2204e-16
     for double precision and 1.1921e-07 for single precision.

     When called with no arguments, return a scalar with the value ‘eps
     (1.0)’.

     Given a single argument X, return the distance between X and the
     next largest value.

     When called with more than one argument the first two arguments are
     taken as the number of rows and columns and any further arguments
     specify additional matrix dimensions.  The optional argument CLASS
     specifies the return type and may be either "double" or "single".

     See also: Note: realmax, Note: realmin,
     Note: intmax, Note: flintmax.

 -- : realmax
 -- : realmax (N)
 -- : realmax (N, M)
 -- : realmax (N, M, K, ...)
 -- : realmax (..., CLASS)
     Return a scalar, matrix, or N-dimensional array whose elements are
     all equal to the largest floating point number that is
     representable.

     The actual value is system dependent.  On machines that support
     IEEE floating point arithmetic, ‘realmax’ is approximately
     1.7977e+308 for double precision and 3.4028e+38 for single
     precision.

     When called with no arguments, return a scalar with the value
     ‘realmax ("double")’.

     When called with a single argument, return a square matrix with the
     dimension specified.

     When called with more than one scalar argument the first two
     arguments are taken as the number of rows and columns and any
     further arguments specify additional matrix dimensions.

     The optional argument CLASS specifies the return type and may be
     either "double" or "single".

     See also: Note: realmin, Note: intmax,
     Note: flintmax, Note: eps.

 -- : realmin
 -- : realmin (N)
 -- : realmin (N, M)
 -- : realmin (N, M, K, ...)
 -- : realmin (..., CLASS)
     Return a scalar, matrix, or N-dimensional array whose elements are
     all equal to the smallest normalized floating point number that is
     representable.

     The actual value is system dependent.  On machines that support
     IEEE floating point arithmetic, ‘realmin’ is approximately
     2.2251e-308 for double precision and 1.1755e-38 for single
     precision.

     When called with no arguments, return a scalar with the value
     ‘realmin ("double")’.

     When called with a single argument, return a square matrix with the
     dimension specified.

     When called with more than one scalar argument the first two
     arguments are taken as the number of rows and columns and any
     further arguments specify additional matrix dimensions.

     The optional argument CLASS specifies the return type and may be
     either "double" or "single".

     See also: Note: realmax, Note: intmin,
     Note: eps.


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