GRADE

Purpose:

Ranks the indices of a series in descending or ascending order.

GRADE(series, order)

series

A series or table.

order

Optional. An integer or string, the sort direction.

0 or "descend"	:	descending order (default)
1 or "ascend"	:	ascending order

Series that contains the indices (i.e. sample numbers) of the sorted input series.

W1: {6, 2, 4, 1, 8}

W2: grade(W1)

returns the series {5, 1, 3, 2, 4}, the indices of W1 in descending order.

W3: sort(W1)

W4: W1[W2]

Both W3 and W4 contain the series {8, 6, 4, 2, 1}, the sorted values of W1 in descending order.

a = int(rand(5)*10);

b = grade(col(a, 1));

c = a[b, ..];

Series a contains a 5x5 table of random integers. Series c sorts all the columns of a based on the sorted values of the first column of a.

As shown in the last example, GRADE is useful for sorting series or tables based on a root series.

GRADE performs a stable sort where the original order of duplicate values is preserved. See SORT for more details.