function y0 = Liniar(x,y,x0)
    n=length(x);
    if(x0 <= x(1))
        i = 1;
        y0 = ((x0-x(i))*(y(i+1)-y(i))/(x(i+1)-x(i))) + y(i);
    endif
    for i = 1 : n-1
        if (x0 > x(i) && x0 < x(i+1))
            y0 = ((x0-x(i))*(y(i+1)-y(i))/(x(i+1)-x(i))) + y(i);
            break;
        endif
    endfor
    if(x0 > x(n))
        i = n-1;
        y0 = ((x0-x(i))*(y(i+1)-y(i))/(x(i+1)-x(i))) + y(i);
    endif
endfunction