Pivoting Strategies
Pivoting strategies: partial pivoting, scaled partial pivoting and why small pivots cause round-off errors.
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Notes
Partial pivoting: swap so the LARGEST |entry| in the column is the pivot. Scaled partial pivoting: compare |aᵢₖ|/sᵢ, sᵢ = largest |entry| in row i.
Trap A tiny pivot multiplies round-off errors: that’s why we pivot.
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