## DOUBLE Convert to 64-bit Floating Point

Section: Type Conversion Functions

### Usage

Converts the argument to a 64-bit floating point number. The syntax for its use is

       y = double(x)

where `x` is an `n`-dimensional numerical array. Conversion follows the general C rules. Note that both `NaN` and `Inf` are both preserved under type conversion.

### Example

The following piece of code demonstrates several uses of `double`. First, we convert from an integer (the argument is an integer because no decimal is present):

    --> double(200)

    ans =

     200

    -->
    quit

In the next example, a single precision argument is passed in (the presence of the `f` suffix implies single precision).

    --> double(400.0f)

    ans =

     400

    -->
    quit

In the next example, a dcomplex argument is passed in. The result is the real part of the argument, and in this context, `double` is equivalent to the function `real`.

    --> double(3.0+4.0*i)

    ans =

     3

    -->
    quit

In the next example, a string argument is passed in. The string argument is converted into an integer array corresponding to the ASCII values of each character.

    --> double('helo')

    ans =

     104 101 108 111

    -->
    quit

In the last example, a cell-array is passed in. For cell-arrays and structure arrays, the result is an error.

    --> double({4})
    Error: Cannot convert cell-arrays to any other type.
    -->
    quit