Array that contains a geometric series

Hi, Is there a short way to create an array in which the elements are making a geometric series?

like for example the following array:

x=[1 2 4 8 16 32 64]

Thanks, Shir

Answer 1

[Roger Stafford]

A general form for a geometric series is:

[a,a*r,a*r^2,a*r^3,...]

You can generate n of these by:

s = a*r.^(0:n-1);

[shir shalom]

Thank you! that's a great general solution.

Answer 2

[John D'Errico]

2.^(0:6)

[shir shalom]

Thank you, but actually if I want to start at 0.5 then it won't work.

Is there a way using multiplication instead of ^ ?

[John D'Errico]

You could have said that the first time. But what is wrong then with this?

2.^(-1:6)

It really won't work? I guess I need to learn this new math then.

Or, for a more general form, with some other start point:

0.1*2.^(0:6)

Could I have used a loop? Of course. But why? Learn to use Matlab.

[shir shalom]

Yes, sorry of course it works. I guess I was too tired to think last night. Thanks alot!