clear all , close all
format short

t = (0:999)/1000;
ft =[-4*t(1:500).^2+4*t(1:500) , ones( 1,499 ),zeros(1,1)];
figure(1)
plot ( t , ft ) , grid
title ( 'Zad 10' )
xlabel ( 't' )
ylabel ( 'f(t)' )

%f0=0.834; - dla tego jest idealnie
%f0=0.833;
f0=0.833;
%f0=(-1/pi^2*0^2)+j*((pi^2*0^2-2+2*(-1)^0)/(2*pi^3*0^3));
k = (1:20 ).' ;


fk=-1./(pi^2*k.^2)+j*((pi^2*k.^2-2+2*(-1).^k)./(2*pi^3*k.^3));
%fk=-1./(pi^2*k.^2)+j*((pi^2*k.^2-2+2*(-1).^k)./(2*pi^3*k.^3));
%fk=-1./(pi^2*k.^2)+j*((pi^2*k.^2-2+2*(-1).^k)./(2*pi^3*k.^3));
disp ( ' k |Fk| arg (Fk) [ deg ] ' )
[k , abs( fk ) , angle( fk ) *180/pi ]
x=f0 ;
figure (2)

% l to L
for l =1:20
    x=x+2*abs(fk(l))*cos(l*2*pi*t+angle(fk(l))) ;
    plot ( t,ft,t,x,'-m') , grid
    txt=num2str(l);
    title(['k = ',txt])
    xlabel('t')
    ylabel('f(t)')
    pause
end