[ MATLAB Tutorial - Lession 12] Number

MATLAB supports various numeric classes that include signed and unsigned integers and single-precision and double-precision floating-point numbers. By default, MATLAB stores all numeric values as double-precision floating point numbers.

You can choose to store any number or array of numbers as integers or as single-precision numbers.

All numeric types support basic array operations and mathematical operations.

Conversion to Various Numeric Data Types

MATLAB provides the following functions to convert to various numeric data types −

Function	Purpose
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

Example

Create a script file and type the following code −

 Live Demo

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

When you run the file, it shows the following result −

x =

   39.900   26.025   47.100

x =

   39.900   26.025   47.100

x =

   38  23  45

x =

   38  23  45

x =

   38  23  45

x =

   38  23  45

Example

Let us extend the previous example a little more. Create a script file and type the following code −

 Live Demo

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

When you run the file, it shows the following result −

x =

   38  23  45

x =

   38  23  45

x = 
{
   [1,1] = 38
   [1,2] = 23
   [1,3] = 45
}

Smallest and Largest Integers

The functions intmax() and intmin() return the maximum and minimum values that can be represented with all types of integer numbers.

Both the functions take the integer data type as the argument, for example, intmax(int8) or intmin(int64) and return the maximum and minimum values that you can represent with the integer data type.

Example

The following example illustrates how to obtain the smallest and largest values of integers. Create a script file and write the following code in it −

 Live Demo

% displaying the smallest and largest signed integer data
str = 'The range for int8 is:\n\t%d to %d ';
sprintf(str, intmin('int8'), intmax('int8'))

str = 'The range for int16 is:\n\t%d to %d ';
sprintf(str, intmin('int16'), intmax('int16'))

str = 'The range for int32 is:\n\t%d to %d ';
sprintf(str, intmin('int32'), intmax('int32'))

str = 'The range for int64 is:\n\t%d to %d ';
sprintf(str, intmin('int64'), intmax('int64'))
 
% displaying the smallest and largest unsigned integer data
str = 'The range for uint8 is:\n\t%d to %d ';
sprintf(str, intmin('uint8'), intmax('uint8'))

str = 'The range for uint16 is:\n\t%d to %d ';
sprintf(str, intmin('uint16'), intmax('uint16'))

str = 'The range for uint32 is:\n\t%d to %d ';
sprintf(str, intmin('uint32'), intmax('uint32'))

str = 'The range for uint64 is:\n\t%d to %d ';
sprintf(str, intmin('uint64'), intmax('uint64'))

When you run the file, it shows the following result −

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:
 0 to 0 
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 -1 
ans = The range for uint64 is:
 0 to 18446744073709551616 

Smallest and Largest Floating Point Numbers

The functions realmax() and realmin() return the maximum and minimum values that can be represented with floating point numbers.

Both the functions when called with the argument 'single', return the maximum and minimum values that you can represent with the single-precision data type and when called with the argument 'double', return the maximum and minimum values that you can represent with the double-precision data type.

Example

The following example illustrates how to obtain the smallest and largest floating point numbers. Create a script file and write the following code in it −

 Live Demo

% displaying the smallest and largest single-precision 
% floating point number
str = 'The range for single is:\n\t%g to %g and\n\t %g to  %g';
sprintf(str, -realmax('single'), -realmin('single'), ...
   realmin('single'), realmax('single'))

% displaying the smallest and largest double-precision 
% floating point number
str = 'The range for double is:\n\t%g to %g and\n\t %g to  %g';
sprintf(str, -realmax('double'), -realmin('double'), ...
   realmin('double'), realmax('double'))

When you run the file, it displays the following result −

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