It’s giving you one point because that’s all you’re asking it to do.
A few tweaks, including subscripting ‘x’, ‘y’ and ‘z’ and all will be well:
function z = my_staircase(a,b,h,n)
tv = 0:2*pi*n;
for k1 = 1:length(tv)
t = tv(k1);
r=((a*b)*exp(-.04*t))/sqrt((b*cos(t)^2)+ (a*sin(t))^2);
x(k1)=r*cos(t);
y(k1)=r*sin(t);
z(k1)=(h*t)/(2*pi*n);
end
hold on
plot3(x,y,z)
xlabel('x(m)'); ylabel('y(m)');zlabel('z(m)');
grid on
view([-30 30])
end
Changing the view parameters (I added that) help too.
