options ps=65;

title 'SAS(IML)example21';

/*creating a matrix from a SAS dataset*/

data imldata;

input x1 x2 x3;

datalines;

2 4 8

3 9 1

9 4 8

1 1 1

2 7 8

;

run;

proc iml;

use imldata;

read all into imlmatrix;

read all var{x1 x3} into imlmatrix0;

*imlmnew=t(imlmatrix)*imlmatrix0;

print imlmatrix imlmatrix0;

print imlmatrix, imlmatrix0;

quit;

*run;

/*creating a SAS matrix and then a dataset from the matrix*/

proc iml;

imlmatrix1={

2 4 8,

3 9 1,

9 4 8,

1 1 1,2 7 8}

;

print imlmatrix1;

create newdata from imlmatrix1;

append from imlmatrix1;

close newdata;

quit;

run;

proc print data=newdata;

run;

/*matrix operation and eigenvalues and vectors*/

proc iml;

a={1 3 4,7 1 0};

rown_a=nrow(a);

coln_a=ncol(a);

print a, rown_a, coln_a;

ata=a*t(a);

*rootata=root(ata);

*rootsq=t(rootata)*rootata;

print ata; *,rootata,rootsq;

ata_inv=inv(ata);

test=(ata_inv)*(ata);

print ata_inv,test;

eval=eigval(ata);

evec=eigvec(ata);

print eval, evec;

call eigen(lambda,p,ata);

print lambda, p;

lam_half=root(diag(lambda));

ata_half=p*lam_half*t(p);

testt=p*diag(lambda)*t(p);

print lam_half, ata_half, testt;

call svd(left,mid,right,ata);

print left,mid,right;

quit;