| 释义 |
ˈpivoting, vbl. n.
[f. pivot v. + -ing1.]
1. The action of the vb. pivot.
1855Hyde Clarke Dict. 292/2 Pivoting, pivotwork.
2. Math. The use of a pivot (sense 3 e) as a means of making a column of a determinant or matrix consist entirely of zeros except for one unit element; also, pivotal condensation; partial pivoting, pivoting in which the choice of pivot at each stage is restricted to the largest element in the first column (or the first row) of the relevant part of the matrix, rather than the largest in all its columns or rows (complete pivoting, total pivoting, or full pivoting).
1961Jrnl. Assoc. Computing Machinery VIII. 282 We derive first an upper bound for R when a general matrix is reduced to triangular form by Gaussian elimination, selecting as pivotal element at each stage the element of maximum modulus in the whole of the remaining square matrix. We refer to this as ‘complete’ pivoting for size, in contrast to the selection of the maximum element in the leading column at each stage, which we call ‘partial’ pivoting for size. 1963N. Macon Numerical Anal. v. 59 The effect of pivoting on rounding errors. 1968Fox & Mayers Computing Methods for Scientists & Engineers v. 86 Partial pivoting is generally satisfactory, and..can be made still better, by the use of fl2 arithmetic.., in a manner which cannot easily be performed with total pivoting. 1973Phillips & Taylor Theory & Appl. Numerical Anal. viii. 197 Partial pivoting using only row interchanges is preferable to that with only column interchanges. |