Why is left alignment off?

[OhmsG]

I have a very simple CEP script.  In it I create a new group with different elements.

I then attempt to place this group like so:

newGroup.left = 597;

When I do this it runs in illustrator but when i see the X value it appears like so:

597.8503 pt

What is going on with it? Why would it chnage add the additional .8503?

[CarlosCanto · Accepted solution]

left includes stroke width, use position[0] instead

[OhmsG]

@CarlosCanto 

THANK YOU FOR THE ANSWER!