Function direction 

pub fn direction(
    tx: &mut Transaction,
    ratios: &[f64],
) -> Result<EntityId, GeometryError>

Stage an IfcDirection.

Ratios are written exactly as given. IFC direction ratios are not required to be unit length, and the reader documents that it returns them unnormalized, so normalizing here would silently disagree with the read direction and discard a magnitude the file was entitled to express.

Errors

Refuses a non-finite ratio, a count outside 2..=3, and an all-zero vector, which denotes no direction at all and cannot be normalized downstream.