SORT command

Syntax: SORT x { x1 x2 ... }
Qualifiers: \UP, \DOWN
Defaults: \UP

The SORT command sorts vectors into ascending or descending order. By default, the vector x is sorted into ascending order. Ascending order means that element 1 will be the smallest element. To sort vector x into descending order, use the \DOWN qualifier. Descending order means that element 1 will be the largest. Vector x will be altered. If other vectors, xI, are entered, then they will not be sorted, but they will be re-arranged in the same way that x is re-arranged. For example, if element x[i] becomes x[j] because of sorting, then xI[i] will become xI[j].

Example 1

Suppose you have a data vector, X = [1;2;3;4;5]
To sort X into descending order, enter:

SORT\DOWN X

after which X = [5;4;3;2;1]

Example 2

Suppose you have three data vectors, X, Y, and Z, which represent rectangular coordinates and an associated altitude: X = [1;2;3;4;5], Y = [10;8;6;4;2], Z = [-.3;-1;-.5;2;-2]

If you want to sort Z into descending order, without breaking up the triplets, enter:

SORT\DOWN Z X Y

After which the vectors are: X = [4;1;3;2;5], Y = [4;10;6;8;2], Z = [2;-.3;-.5;-1;-2]

Example 3

Suppose you have three data vectors, X, Y, and Z, which represent rectangular coordinates and an associated altitude: X = [1;2;3;4;5], Y = [10;8;6;4;2], Z = [-.3;-1;-.5;2;-2]

If you want to sort Y into ascending order, without breaking up the triplets, enter:

SORT\DOWN Y X Z

After which the vectors are: X = [5;4;3;2;1], Y = [2;4;6;8;10], Z = [-2;2;-.5;-1;-.3]