# MATLAB數字

MATLAB 支持各種數字類，包括符號和無符號的整數及單精度和雙精度浮點數。默認情況下，MATLAB 存儲所有數值為雙精度浮點數。

## 各種數字數據類型的轉換

MATLAB提供各種數字數據類型轉換為以下功能：

double Converts to double precision number
single Converts to single precision number
int8 Converts to 8-bit signed integer
int16 Converts to 16-bit signed integer
int32 Converts to 32-bit signed integer
int64 Converts to 64-bit signed integer
uint8 Converts to 8-bit unsigned integer
uint16 Converts to 16-bit unsigned integer
uint32 Converts to 32-bit unsigned integer
uint64 Converts to 64-bit unsigned integer

## 例子

```x = single([5.32 3.47 6.28]) .* 7.5
x = double([5.32 3.47 6.28]) .* 7.5
x = int8([5.32 3.47 6.28]) .* 7.5
x = int16([5.32 3.47 6.28]) .* 7.5
x = int32([5.32 3.47 6.28]) .* 7.5
x = int64([5.32 3.47 6.28]) .* 7.5```

```x =
39.9000   26.0250   47.1000
x =

39.9000   26.0250   47.1000
x =
38   23   45
x =
38     23     45
x =
38          23          45
x =
38                   23                   45
```

## 例子

```x = int32([5.32 3.47 6.28]) .* 7.5
x = int64([5.32 3.47 6.28]) .* 7.5
x = num2cell(x)```

```x =
38          23          45
x =
38                   23                   45
x =
[38]    [23]    [45]
```

## 例子

```% displaying the smallest and largest signed integer data
str = 'The range for int8 is:
%d to %d ';
sprintf(str, intmin('int8'), intmax('int8'))
str = 'The range for int16 is:
%d to %d ';
sprintf(str, intmin('int16'), intmax('int16'))
str = 'The range for int32 is:
%d to %d ';
sprintf(str, intmin('int32'), intmax('int32'))
str = 'The range for int64 is:
%d to %d ';
sprintf(str, intmin('int64'), intmax('int64'))

% displaying the smallest and largest unsigned integer data
str = 'The range for uint8 is:
%d to %d ';
sprintf(str, intmin('uint8'), intmax('uint8'))
str = 'The range for uint16 is:
%d to %d ';
sprintf(str, intmin('uint16'), intmax('uint16'))
str = 'The range for uint32 is:
%d to %d ';
sprintf(str, intmin('uint32'), intmax('uint32'))
str = 'The range for uint64 is:
%d to %d ';
sprintf(str, intmin('uint64'), intmax('uint64'))```

```ans =
The range for int8 is:
-128 to 127
ans =
The range for int16 is:
-32768 to 32767
ans =
The range for int32 is:
-2147483648 to 2147483647
ans =
The range for int64 is:
-9223372036854775808 to 9223372036854775807
ans =
The range for uint8 is:
0 to 255
ans =
The range for uint16 is:
0 to 65535
ans =
The range for uint32 is:
0 to 4294967295
ans =
The range for uint64 is:
0 to 1.844674e+19

```

## 實例

```% displaying the smallest and largest single-precision
% floating yiibai number
str = 'The range for single is:
%g to %g and
%g to  %g';
sprintf(str, -realmax('single'), -realmin('single'), ...
realmin('single'), realmax('single'))
% displaying the smallest and largest double-precision
% floating yiibai number
str = 'The range for double is:
%g to %g and
%g to  %g';
sprintf(str, -realmax('double'), -realmin('double'), ...
realmin('double'), realmax('double'))```

```ans =
The range for single is:
-3.40282e+38 to -1.17549e-38 and
1.17549e-38 to  3.40282e+38
ans =
The range for double is:
-1.79769e+308 to -2.22507e-308 and
2.22507e-308 to  1.79769e+308```