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Target vector

The known correct outputs, one per data sample.

A vector $\mathbf{y}$ collecting the true label or response value for each of the $n$ samples in a design matrix $\mathbf{X}$ , in the same row order.

Examples

For a spam-detection dataset, $\mathbf{y}$ holds a 0 or 1 (not-spam/spam) for every email.