typecast

Convert an integer to an unsigned integer of the same storage size.

X = int16(-1)

X =int16-1

Y = typecast(X,'uint16')

Y =uint1665535

上海ow the bit patterns in hexadecimal representation. Converting the data type by usingtypecastdoes not change the underlying data.

formathexX

X =int16ffff

Y = typecast(X,'uint16')

Y =uint16ffff

Create a 1-by-4 vector of 8-bit integers.

X = int8([77 60 43 26])

X =1x4 int8 row vector77 60 43 26

Convert the four 8-bit integers, which use 4 bytes (32 bits) of storage, to a single-precision number that also uses 4 bytes of storage.

Y = typecast(X,'single')

Y =single3.5411e-23

上海ow the bit patterns in hexadecimal representation. In hexadecimal notation, 1 byte (8 bits) is represented by two digits. Thetypecastfunction rearranges the bit patterns without modifying the data.

formathexX

X =1x4 int8 row vector4d 3c 2b 1a

Y = typecast(X,'single')

Y =single1a2b3c4d

Create a 1-by-3 vector of 32-bit unsigned integers.

X = uint32([1 255 256])

X =1x3 uint32 row vector1 255 256

CastXinto 8-bit unsigned integers usingtypecast. Each 32-bit value is divided into four 8-bit segments. Running this code on a little-endian system produces the following results.

Y = typecast(X,'uint8')

Y =1x12 uint8 row vector1 0 0 0 255 0 0 0 0 1 0 0

The third element ofX, 256, exceeds the maximum value that 8 bits can hold. The converted value in Y(9) thus overflows to Y(10).

Y(9:12)

ans =1x4 uint8 row vector0 1 0 0

You can convertYback to 32-bit unsigned integers without changing the underlying data.

X2 = typecast(Y,'uint32')

X2 =1x3 uint32 row vector1 255 256

Compare the output oftypecastand the output ofcastto see the difference between the two functions.

Z = cast(X,'uint8')

Z =1x3 uint8 row vector1 255 255

X2 = cast(Z,'uint32')

X2 =1x3 uint32 row vector1 255 255

Casts integers from a smaller data type (uint8) into a larger one (uint16). Use hexadecimal representation to show the rearrangement of the bit patterns. Thetypecastfunction returns the output in little-endian style, combining the four 8-bit segments of the input data to produce two 16-bit segments.

formathexX = uint8([44 55 66 77])

X =1x4 uint8 row vector2c 37 42 4d

Y = typecast(X,'uint16')

Y =1 x2 uint16行向量372c 4d42

You can convert the little-endian output to big-endian (and vice versa) using theswapbytesfunction.

Y = swapbytes(typecast(X,'uint16'))

Y =1 x2 uint16行向量2c37 424d