Scripting Guide - SAS

152 Data Structures Chapter 7
Matrices
0 1 0,
0 0 1]
Construct a Matrix with Specific Values
The J() function constructs a matrix with the number of rows and columns that you specify as the first two
arguments, whose elements are all the third argument, for example:
J(3,4,5);
[5 5 5 5,
5 5 5 5,
5 5 5 5]
J(3,4,random normal());
[0.407709113182904 1.67359154091978 1.00412665221308 0.240885679837327,
-0.557848036549455 -0.620833861982722 0.877166783247633 1.50413740148892,
-2.09920574748608 -0.154797501010655 0.0463943433032137 0.064041826393316]
Create a Diagonal Matrix
The Diag() function creates a diagonal matrix from a square matrix (having an equal number of rows and
columns) or a vector. A diagonal matrix is a square matrix whose nondiagonal elements are zero.
D=[ 1 -1 1];
Diag(D);
[1 0 0,
0 -1 0,
0 0 1]
Diag([1,2,3,4]);
[1 0 0 0,
0 2 0 0,
0 0 3 0,
0 0 0 4]
A=[1 2,3 4];
f=[5];
D=Diag(A,f);
[1 2 0
3 4 0
0 0 5]
In the third example, at first glance, not all of the nondiagonal elements are zero. Using matrix notation, the
matrix can be expressed as follows:
[A 0,
0` f]
Where A and f are the matrices from the example, and 0 is a column vector of zeros.
Create a Column Vector from Diagonal Elements
The VecDiag() function creates a column vector from the diagonal elements of a matrix.
v=vecdiag(
[1 0 0 1,