When creating graphs, we’re usually most concerned with what happens near the center of our displays, as this is where most of the important information is generally held. But sometimes, either for aesthetics or clarity, we want to adjust what’s outside of the box – in the margins, labels or tick marks. The
par() function offers several ways to do this and I’ll discuss two that deal primarily with spatial orientation – rather than content – below.
The oma, omd, and omi options