Generalized Variance Chart - Options – Parameters
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Stat > Control Charts  > Multivariate Charts > Generalized Variance > Gen Var Options > Parameters

Use to enter historical data for estimating S. For example, if you have a known process parameter or an estimate obtained from past data, you can enter this value or values. If you do not specify a value for the covariance matrix, Minitab estimates it from the data. You can omit certain subgroups when estimating parameters using Estimate.

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Covariance matrix

Enter one or more matrices for estimating the covariance matrix. Each matrix must be a positive definite square matrix with the same number of rows and columns as columns of data. The elements on the matrix diagonal must be positive. Element (i,j) must equal element (j,i). If you enter only one matrix, all stages use that covariance matrix; otherwise, enter a matrix for each stage.