I create a polyline using a typical statement such as

var pLine =sfc.createPolyline(eval(lineString)).setStroke("yellow");

where lineString is the usual set of coordinate pairs such as[{x: 245, y: 153}, {x: 245, y: 152}, {x: 245, y: 151}, {x: 244, y: 151}, {x: 241, y: 150}, {x: 233, ..." (and so forth)

Then later, the background under the line changes, perhaps as a new jpg image.

Can I redraw the "pLine" without having Dojo recalculate its position by reparsing the lineString?
It seems inefficient to require this recalculation each time.