Scripting Guide - SAS

Chapter 7 Data Structures 151
Matrices
• The returned values are always 1 or greater. If the element in B is smaller than all of the elements in A,
then the function returns a value of 1. If the element in B is greater than all of the elements in A, then
the function returns n, where n is the number of elements in A.
Ranking and Sorting
The Rank() function returns the positions of the numbers in a vector or list, as if the numbers were sorted
from lowest to highest.
E=[1 -2 3 -4 0 5 1 8 -7];
R=Rank(E);
[9,4,2,5,7,1,3,6,8]
If E were sorted from lowest to highest, the first number would be -7. The position of -7 in E is 9.
The original matrix E can then be sorted using the matrix R as subscripts to E.
sortedE=E[R];
[-7,-4,-2,0,1,1,3,5,8]
The Ranking Tie() function returns ranks for the values in a vector or list, with ranks for ties averaged.
Similarly, Ranking() returns ranks for the values in a vector or list, but the ties are ranked arbitrarily.
E=[1 -2 3 -4 0 5 1 8 -7];
Ranking Tie (E);
[5.5, 3, 7, 2, 4, 8, 5.5, 9, 1]
E=[1 -2 3 -4 0 5 1 8 -7];
Ranking (E);
[5, 3, 7, 2, 4, 8, 6, 9, 1]
The Sort Ascending() and Sort Descending() functions sort vectors.
E=[1 -2 3 -4 0 5 1 8 -7];
Sort Ascending (E);
[-7 -4 -2 0 1 1 3 5 8]
E=[1 -2 3 -4 0 5 1 8 -7];
Sort Descending (E);
[8 5 3 1 1 0 -2 -4 -7]
If the argument is not a vector or list, an error message is generated.
Special Matrices
Construct an Identity Matrix
The Identity() function constructs an identity matrix of the dimension that you specify. An identity
matrix is a square matrix of zeros except for a diagonal of ones. The only argument specifies the dimension.
Identity(3);
[1 0 0,