How to create a postive and negative sequence [closed]

Question

I'm currently working on r to bring myself upto scratch. Trying to create a sequence which is

(-10,10,100,100,1000,1000)

My first question is how do I create a sequence that alternates between positive and negative

Secondly how do I create a sequence that multiplies itself by 10 every x amount of numbers.

Answer 1

You can use rep and cumprod creating a sequence that multiplies itself by 10 and multiply with c(-1,1) to alternates between positive and negative:

rep(cumprod(rep(10, 3)), each=2) * c(-1, 1)
#[1]   -10    10  -100   100 -1000  1000