proc iml; 

reset autoname;  /* Causes output to display row # and col # */

/* Construct a vector */ 

/* Create a 1 x 5 vector; columns are separated by a space */
v = {1 2 3 4 5} ;
print v;

/* Create a 2x2 matrix */
m = {1 2,3 4};
print m;

/* Change a value in vector/matrix; change the value 3 to 6 */
v[1,3] = 6;
print v; 


/* Change the value 3 to 6 in matrix m */
m[2,1] = 6;
print m;

/* Special matrices */
I = { 1 0 0 , 0 1 0 , 0 0 1};
print I;

/* Identity matrix of dimensions 3x3 */
I3 = i(3);
print i3; 

/* Vector of ones */
/* j(# rows, # cols, value) */

iota = j(5,1,1);
print iota;

/* Create an empty 4 x 4 matrix, that will later store output */
empty = j(4,4,.);
print empty;

/* Loops */
do i=1 to 4;
	do j=1 to 4;
		empty[i,j] = i+j;
	end;
end;
print empty;

/* Matrix operations */ 
/* Transposes and inverses */

vt = t(v); 
vt = v` ;
print vt;

minv = inv(m);
print minv; 

/* Multiplications */

/* Elementwise */
vv = v # v;
print vv;

/* Matrix multiplication */
mm = m * minv;
print mm;

/* Importing SAS datasets into IML
	**Note: data set has to be imported into SAS first */

/* Uses the bweight dataset, reads all obs and columns into matrix 
	named "bw" */
use sashelp.bweight;
read all into bw;
print bw;

read point(1:100) var {weight black married} into bw1;
print bw1;