How do I create a vector with a multiply sequence?

Can I replace this loop?

vector(1)=100;
for i=2:10
   vector(i)=vector(i-1)*0.7;
end
  %%vector(10) will be 4.0354

I want to write the sequence , something like this:

vector=100:*0.7:4.0354

possible?

[Sean de Wolski]

+1, this is a well written question that can evoke a lot of good solutions with an opportunity for us to all learn.

[Jan]

Sean, you are right. +1

[Sean de Wolski]

How would you do this with filter?

Answer 1

[Sean de Wolski]

vector = 0.7.^(0:9)*100

And golf:

v=.7.^(0:9)*100

[Andrei Bobrov]

+1

Answer 2

[Andrei Bobrov]

vector = [1 cumprod(ones(1,9)*.7)]*100;

more variant

o10 = ones(10);
vector = 100*prod(o10 - .3*triu(o10,1));

Answer 3

[Jan]

vector    = repmat(0.7, 1, 10);
vector(1) = 100;
vector    = cumprod(vector);

Or as one-liner:

vector = cumprod([100, repmat(0.7, 1, 9)]);

Answer 4

[Jan]

An of course:

vector = [100, 70, 49, 34.3, 24.01, 16.807, 11.7649, ...
          8.23543, 5.764801, 4.0353607];

This is fast, but not very flexible. :-)

[Andrei Bobrov]

+1, yes!

Answer 5

[Honglei Chen]

Just for fun

filter(1,[1 -0.7],[100 0 0 0 0 0 0 0 0 0])

[Sean de Wolski]

yay!

Answer 6

[Honglei Chen]

Another one

flipud(100*diag(vander(repmat(0.7,1,10))))