% Douglas N. Arnold, dna@math.psu.edu, 11/96
% for use with ginterp
function rungec(n)
global xmin xmax ymin ymax x y
xmin=-6;
xmax=6;
ymin=-.5;
ymax=1.5;
a=-5; b=5;
x=(a+b)/2 + (b-a)/2 * cos( (1:2:2*n+1)*pi/(2*n+2));
y=1./(1+x.^2);

