Multivariate EWMA Chart - Options – Parameters
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Stat > Control  Charts  > Multivariate charts > Multivariate EWMA > MEWMA Options >  Parameters

Enters historical data for estimating m and 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 mean or the covariance matrix, Minitab estimates it from the data. You can omit certain subgroups when estimating parameters using MEWMA Options > Estimate.

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Mean: Enter the historical m's as a single value or a list of values. If you enter one constant, all stages use that value; otherwise, enter a value for each stage.

Covariance matrix: Enter the historical matrices. 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 historical group.