In reply to mario Segal.

I actually think that letting you to do the job is much better than letting the program to decide how to jitter for you, because you have more control on your data and you know better which is the good way and which is not. For example, the program won't know your variable is actually "age" even you call it "age", but apparently, you're not going to jitter "age" by adding the noise from -0.5 to 0.5. This will affect your later inference. Sometimes, even a small decimal counts.