# Matrix Variance mode {% hint style="info" %} This mode is only available when a matrix is active; it is not available in Summary view. {% endhint %} Matrix Variance mode takes an existing matrix and adds additional columns, to show the previous period and variance. It is effectively a combination of Matrix mode and Variance mode. Matrix Variance mode is useful if you want to compare an existing matrix with another period, for example, last year, month or quarter. {% embed url="" %} Matrix Variance and Matrix Share mode {% endembed %} The following example uses Matrix Variance mode to identify which customers have bought downlights but not transformers, both this year and last year: 1. Start with an existing a matrix (this example continues with the example in the [Compare data with Matrix mode](/analytics/compare-data-with-matrix-mode.md) page). 2. Select **Mode** > **Matrix Variance**. The grid updates to display additional columns for the previous period and the variance between the current and previous period.
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