Differences among multiple ways of injecting users

Gatling (Open-Source)
1

Hi all,

I was reading the injection part of the documentation and saw this for rampUsers:
Injects a given number of users with a linear ramp over a given duration.

does that mean:

`
rampUsers(x * y) over (y)

`

is the same as

constantUsersPerSec(x) over (y)
?

also is

rampUsers(x) over (0)

same as

atOnceUsers(x)
?

2

First is yes, second is no.