goptions reset=all; 
axis1 label=(angle=90 font=centb h=1.2);
axis2 offset=(5,5) label=(font = centb); 
%let n=50;  

Data Eigen; pi = 4*atan(1); 
do i= 1 to 20; 
A = (&n-i)*pi/(2*&n-1); 
gamma_2 = 1/(2*cos(A))**2;
gamma_2=gamma_2/(&n*&n); 
limit = 4/((2*i-1)*pi)**2;if i>&n then gamma_2=.; 
output; end; 
 
proc gplot; plot (gamma_2 limit)*i/
       overlay vaxis=axis1 haxis=axis2 hminor=0;
symbol1 v=dot i=needle c=red;
symbol2 v=diamond i=join c=black h=2.5;  
title c=red "First 20 Eigenvalues (n=&n) " c=black " and their Limits";
run;