Polarization and the percentage of up ($\uparrow$) spins: $$\mathrm{Polarization} = \frac{I_\mathrm{up} - I_\mathrm{down}}{I_\mathrm{up} + I_\mathrm{down}} = 2 P_\mathrm{up} - 1 $$ $$P_\mathrm{up} = \frac{I_\mathrm{up}}{I_\mathrm{up}+I_\mathrm{down}}$$ Spin $\uparrow$ 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Polarization -1 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0