# Multiply x sequentially with items of a vector

2 views (last 30 days)
Christoph Meier on 7 Aug 2015
Commented: Torsten on 7 Aug 2015
Dear MATLAB community,
I would like to construct an index, which should start with 100. I have computed a vector, which then determines the change in the index in each time period. For example, for 4 time periods:[1.1,1.2,1.3,1.4] Basically, the operation should compute and produce the following vector:
1. 100*1.1
2. (100*1.1)*1.2
3. ((100*1.1)*1.2)*1.3
4. (((100*1.1)*1.2)*1.3)*1.4
Thank you very much in advance! I appreciate any help, as I am still a beginner with MATLAB.

Torsten on 7 Aug 2015
Edited: Torsten on 7 Aug 2015
vder(1)=v(1);
for l=2:length(v)
vder(l)=vder(l-1)*v(l);
end
vder=100*vder;
v is the original vector, vder is the vector you are looking for.
Best wishes
Torsten.

Stephen Cobeldick on 7 Aug 2015
See Walter Roberson's answer for the simpler and faster way to do this.
Torsten on 7 Aug 2015
And cumprod.m works without a loop ?
Best wishes
Torsten.