int8, int16, int32, int64 (MATLAB Functions)

Convert to signed integer

Syntax

I = int8(X)
I = int16(X)
I = int32(X)
I = int64(X)

Description

I = int*(X) converts the elements of array X into signed integers. X can be any numeric object (such as a double). The results of an int* operation are shown in the next table.

Operation
Output Range
Output Type
Bytes per Element
Output Class

int8
-128 to 127
Signed 8-bit integer
1
int8

int16
-32,768 to 32,767
Signed 16-bit integer
2
int16

int32
-2,147,483,648 to 2,147,483,647
Signed 32-bit integer
4
int32

int64
-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
Signed 64-bit integer
8
int64

Operation	Output Range	Output Type	Bytes per Element	Output Class
`int8`	-128 to 127	Signed 8-bit integer	1	`int8`
`int16`	-32,768 to 32,767	Signed 16-bit integer	2	`int16`
`int32`	-2,147,483,648 to 2,147,483,647	Signed 32-bit integer	4	`int32`
`int64`	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	Signed 64-bit integer	8	`int64`

double and single values are rounded to the nearest int* value on conversion. A value of X that is above or below the range for an integer class is mapped to one of the endpoints of the range. For example,

```
int16(40000)
ans =
   32767
```

If X is already a signed integer of the same class, then int* has no effect.

You can define or overload your own methods for int* (as you can for any object) by placing the appropriately named method in an @int* directory within a directory on your path. Type help datatypes for the names of the methods you can overload.

Remarks

Most operations that manipulate arrays without changing their elements are defined for integer values. Examples are reshape, size, the logical and relational operators, subscripted assignment, and subscripted reference.

Some arithmetic operations are defined for integer arrays on interaction with other integer arrays of the same class (e.g., where both operands are int16). Examples of these operations are +, -, .*, ./, .\ and .^. If at least one operand is scalar, then *, /, \, and ^ are also defined. Integer arrays may also interact with scalar double variables, including constants, and the result of the operation is an integer array of the same class. Integer arrays saturate on overflow in arithmetic.

A particularly efficient way to initialize a large array is by specifying the data type (i.e., class name) for the array in the zeros, ones, or eye function. For example, to create a 100-by-100 int64 array initialized to zero, type

```
I = zeros(100, 100, 'int64');
```

An easy way to find the range for any MATLAB integer type is to use the intmin and intmax functions as shown here for int32:

intmin('int32')               intmax('int32')
ans =                         ans =
   -2147483648                   2147483647

See Also

double, single, uint8, uint16, uint32, uint64, intmax, intmin

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