diff2c3.m

Micro Electronic Device Fundermental

format short
%syms x
%plot(x,y1),grid
%plot(x,y1,x,g1),grid
%h=((48*0.5e-4)/135)^(1/4)
h=0.02
x=1:h:1.12
y1=exp(-x.^2).*cos(20*x)
g2=-402*exp(-x.^2).*cos(20.*x)+4*x.^2.*exp(-x.^2).*cos(20*x)+80*x.*exp(-x.^2).*sin(20*x)
m2=(1/(h^2))*((exp(-(x+h).^2).*cos(20*(x+h)))-2*(exp(-x.^2).*cos(20*x))+(exp(-(x-h).^2).*cos(20*(x-h))))
det2=abs(g2-m2)
j=length(x);
fprintf('------------------------------------------------------------\n')
fprintf('  x               g2               m2                det2\n');
fprintf('------------------------------------------------------------\n')
for ii=1:j,
    fprintf('%-10.4f       %-10.4f      %-10.4f      %-10.4e\n',x(ii),g2(ii),m2(ii),det2(ii));
end
plot(x,y1,x,m2),grid