DeltaYaw and DeltaPitch

I haven't found the functions Delatyaw and deltapitch in minib3d.

	Function DeltaYaw:Double( p_eEntity1:TEntity, p_eEntity2:TEntity )
		Local l_dx:Double = 0.0
		Local l_dz:Double = 0.0
	
		l_dx = EntityX(p_eEntity2 ) - EntityX(p_eEntity1 )
		l_dz = EntityZ(p_eEntity2 ) - EntityZ(p_eEntity1 )
		
		Return( -ATan2(l_dx, l_dz) )
	End Function

	Function DeltaPitch:Double( p_eEntity1:TEntity, p_eEntity2:TEntity )
		Local l_dx:Double = 0.0
		Local l_dy:Double = 0.0
		Local l_dz:Double = 0.0
	
		l_dx = EntityX(p_eEntity2 ) - EntityX(p_eEntity1 )
		l_dy = EntityY(p_eEntity2 ) - EntityY(p_eEntity1 )
		l_dz = EntityZ(p_eEntity2 ) - EntityZ(p_eEntity1 )
		
		Return( -ATan2(l_dy, Sqr(l_dx*l_dx + l_dz*l_dz)) )
	End Function