Measures for Errors (Deviations or Residuals) ■Denote efx)yk for 1≤kW ■Maximum error: E.()=mlf()-y.B ■Average error: EUDN24l k1 Root-mean-square error: a=哈2-月 Measures for Errors (Deviations or Residuals) ◼ Denote ek=f(xk )-yk for 1≤k≤N ◼ Maximum error: ◼ Average error: ◼ Root-mean-square error: 1 1 1 1 2 2 2 1 ( ) max{| ( ) |} 1 ( ) | ( ) | 1 ( ) | ( ) | k k k N N k k k N k k k E f f x y E f f x y N E f f x y N    = = = − = −   = −      