TO_DOUBLE

Converts an input value to a double value.The input can be a single- or multi-valued field or an expression. The input
type must be of a boolean, date, string or numeric type.Example:
```esql
ROW str1 = "5.20128E11", str2 = "foo"
| EVAL dbl = TO_DOUBLE("520128000000"), dbl1 = TO_DOUBLE(str1), dbl2 = TO_DOUBLE(str2)
```

Note that in this example, the last conversion of the string isn’t
possible. When this happens, the result is a null value. In this case a
Warning header is added to the response. The header will provide information
on the source of the failure:"Line 1:115: evaluation of [TO_DOUBLE(str2)] failed, treating result as null. Only first 20 failures recorded."A following header will contain the failure reason and the offending value:"java.lang.NumberFormatException: For input string: \"foo\""If the input parameter is of a date type, its value will be interpreted as
milliseconds since the Unix epoch,
converted to double.Boolean true will be converted to double 1.0, false to 0.0.Alias: TO_DBL