P=[1,2,3];
Q=[2,4,-1];
u=Q-P;
u1=[u(1),0,0];
u2=[0,u(2),0];
u3=[0,0,u(3)];
nu1=norm(u1);
nu2=norm(u1);
nu1=norm(u1);

%vektorit
vek{1}=[P;P+u1];nimi{1}='u1';pituus{1}=norm(u1);
vek{2}=[P+u1;P+u1+u2];nimi{2}='u2';pituus{2}=norm(u2);
vek{3}=[P+u1+u2;Q];nimi{3}='u3';pituus{3}=norm(u3);
vek{4}=[P;Q];nimi{4}='u';pituus{4}=norm(Q-P);

plot3(0,0,0,'.')
hold on

for k=1:4
plot3(vek{k}(:,1),vek{k}(:,2),vek{k}(:,3))
%text(mean(vek{k}(:,1)),mean(vek{k}(:,2)),mean(vek{k}(:,3)),nimi{k})
%text(mean(vek{k}(:,1)),mean(vek{k}(:,2)),mean(vek{k}(:,3)),num2str(pituus{k}))
text(mean(vek{k}(:,1)),mean(vek{k}(:,2)),mean(vek{k}(:,3)),['|' nimi{k} '|=' num2str(pituus{k})])

end

%pisteet
pos{1}=P;nimi{1}='P';
pos{2}=Q;nimi{2}='Q';

for k=1:2
plot3(pos{k}(1),pos{k}(2),pos{k}(3),'*')
text(pos{k}(1),pos{k}(2),pos{k}(3),nimi{k})
end

pisteet=[P;Q];
maksimi=max(pisteet);
minimi=min(pisteet);
MA=maksimi+1;
MI=minimi-1;

%box on
grid on, axis equal
axis([MI(1) MA(1) MI(2) MA(2) MI(3) MA(3)])