Algorithm 1 Collaborative representation based classifier.
	1:	Normalize $\mathit{X}$ to have $l_2$ norm
	2:	Calculate the collaborative representation coefficients vector $\widehat{\mathit{\alpha }}$ using
$\widehat{\mathit{\alpha }}=argmin\alpha {∥\mathit{y}-\mathit{X}\mathit{\alpha }∥}_2^2+\lambda {∥\mathit{\alpha }∥}_2^2$
	3:	Calculate the the residuals between test sample $\mathit{y}$ and the representation of each class using formulation and obtain the identity of $\mathit{y}$ using Equation (3):
$identity\left(\mathit{y}\right)={argmin}_i{\parallel \mathit{y}-{\mathit{X}}_{\mathit{i}}{\mathit{\alpha }}_i\parallel }_2$