FLOATw.d Format

This format is useful in operating environments where a float value is not the same as a truncated double. Values that are written by FLOAT4. typically are those meant to be read by some other external program that runs in your operating environment and that expects these single-precision values. If the value that is to be formatted is a missing value, or if it is out-of-range for a native single-precision, floating-point value, a single-precision value of zero is generated.