GNU Octave Manual Version 3 by John W. Eaton, David Bateman, Søren Hauberg Paperback (6"x9"), 568 pages ISBN 095461206X RRP £24.95 ($39.95) |
4.3 Integer Data Types
Octave supports integer matrices as an alternative to using double precision. It is possible to use both signed and unsigned integers represented by 8, 16, 32, or 64 bits. It should be noted that most computations require floating point data, meaning that integers will often change type when involved in numeric computations. For this reason integers are most often used to store data, and not for calculations.
In general most integer matrices are created by casting existing matrices to integers. The following example shows how to cast a matrix into 32 bit integers.
float = rand (2, 2) => float = 0.37569 0.92982 0.11962 0.50876 integer = int32 (float) => integer = 0 1 0 1
As can be seen, floating point values are rounded to the nearest integer when converted.
- Built-in Function: isinteger (x)
- Return true if x is an integer object (int8, uint8, int16, etc.).
Note that
isinteger (14)
is false because numeric constants in expressions are double precision floating point values.See also isreal, isnumeric, class, isa
- Built-in Function: int8 (x)
- Convert x to 8-bit integer type.
- Built-in Function: uint8 (x)
- Convert x to unsigned 8-bit integer type.
- Built-in Function: int16 (x)
- Convert x to 16-bit integer type.
- Built-in Function: uint16 (x)
- Convert x to unsigned 16-bit integer type.
- Built-in Function: int32 (x)
- Convert x to 32-bit integer type.
- Built-in Function: uint32 (x)
- Convert x to unsigned 32-bit integer type.
- Built-in Function: int64 (x)
- Convert x to 64-bit integer type.
- Built-in Function: uint64 (x)
- Convert x to unsigned 64-bit integer type.
- Built-in Function: intmax (type)
- Return the largest integer that can be represented in an integer type.
The variable type can be
int8
- signed 8-bit integer.
int16
- signed 16-bit integer.
int32
- signed 32-bit integer.
int64
- signed 64-bit integer.
uint8
- unsigned 8-bit integer.
uint16
- unsigned 16-bit integer.
uint32
- unsigned 32-bit integer.
uint64
- unsigned 64-bit integer.
The default for type is
uint32
.See also intmin, bitmax
- Built-in Function: intmin (type)
- Return the smallest integer that can be represented in an integer type.
The variable type can be
int8
- signed 8-bit integer.
int16
- signed 16-bit integer.
int32
- signed 32-bit integer.
int64
- signed 64-bit integer.
uint8
- unsigned 8-bit integer.
uint16
- unsigned 16-bit integer.
uint32
- unsigned 32-bit integer.
uint64
- unsigned 64-bit integer.
The default for type is
uint32
.See also intmax, bitmax
ISBN 095461206X | GNU Octave Manual Version 3 | See the print edition |