function sroubovice(polomer)

fi = 0:0.1:2*pi;
x = polomer.*cos(fi);
y = polomer.*sin(fi);
z = fi;

plot3(x,y,z,'r*',x,y,z+2*pi,'gx--'),
    xlabel('x'), ylabel('y'),
    title('Sroubovice'), grid on, axis tight
