Another method to obtain canonical models with linear terms

Another method to obtain canonical models with linear terms 

The transformation of the experimental variables into the canonical variables by translation and rotation is given by 

define a coordinate system Zp-Zi which is obtained by translating the zi...2ij to the center of the experimental domain. This tranformation is given by 

The linear coefficients of the canonical model is therefore easily computed from the corresponding eigenvalues and the coordinates of the stationary point. 

By this technique it is possible to make the translation only for those Zj axes along which the coordinates of the design center are remote. To explore the ridges it is not necessary to transform those z, axes which pass through the experimental domain. 

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