Function write_points 

pub fn write_points<W: Write>(
    out: &mut W,
    pos_x: &[f32],
    pos_y: &[f32],
    color: Option<&[u8]>,
) -> Result<()>

Writes the point section: a # points N marker, a header row, then one line per agent.

The color column appears only if the model carries the lane. A point without a finite position is left out.

Errors

Returns the error of the first write that fails.