get_fpnum

Get value of a floating point number (4/8 bytes)
     ea - linear address or string that contains float number byte rep
Returns: a floating point number at the specified address.
If the bytes at the specified address cannot be represented as a floating
point number, then return integer value -1.
If the first argument has not long or string type, throw an exception

float get_fpnum(long ea, long size);

// Convenience macros:
#define get_float(ea)     get_fpnum(ea, 4)
#define get_double(ea)    get_fpnum(ea, 8)