#Métodos Numéricos - 2023. IMERL, Fing
#Código de ejemplo para el ejercicio 4 del práctico 4
A=3;
f=@(x) sign(x-3)*sqrt(abs(x-3));

figure(1);
X=linspace(-2,6);
Y=sign(X-A).*sqrt(abs(X-A));
plot(X,Y,'LineWidth',2);
grid on;
hold on;
set(gca,'fontsize', 26);
title('sign(x-a)*sqrt(abs(x-a))','FontSize',28);
line([-2,8],[0,0],'linestyle','-.','color',[0.5,0.5,0.5],'LineWidth',1);
line([0,0],[-3,2],'linestyle','-.','color',[0.5,0.5,0.5],'LineWidth',1);

x=[-2;2];
kmax=100;
k=3;
pend=(f(x(k-1))-f(x(k-2,1)))/(x(k-1,1)-x(k-2,1));
linea=linea=line([x(k-1),x(k-2)],[f(x(k-1)),f(x(k-2))],'LineWidth',2);
linea_a=line([x(k-1),x(k-1)],[-3,2],'LineWidth',2,'linestyle','--','color',[0,0,0]);
linea_b=line([x(k-2),x(k-2)],[-3,2],'LineWidth',2,'linestyle','--','color',[0,0,0]);

while (k<kmax) & (abs(x(end)-x(end-1)) > eps*abs(x(end)))
  pause(2);
  delete(linea);
  delete(linea_a);
  delete(linea_b);
  pend=(f(x(k-1))-f(x(k-2)))/(x(k-1)-x(k-2));
  x_=x(k-1)-f(x(k-1))/pend;
  x=[x;x_];
  k=k+1;

  linea=line([x(k-1),x(k-2)],[f(x(k-1)),f(x(k-2))],'LineWidth',2);
  linea_a=line([x(k-1),x(k-1)],[-3,2],'LineWidth',2,'linestyle','--','color',[0,0,0]);
  linea_b=line([x(k-2),x(k-2)],[-3,2],'LineWidth',2,'linestyle','--','color',[0,0,0]);

endwhile