Whether or not one of the coordinates should not be jittered.
这句话中jitterd的翻译。
相似的语句还有：To  avoid  problems of  overplotting, the
data  have  been jittered  or blurred (Chambers et  aI.,  1983);  that  is,  uniform
U(-0.5,0.5)  noise  is  added to each element of  the  original data.  This trick
should be  regularly  employed for  data  recorded  with  3  or fewer significant
digits (with an appropriate range on the added uniform noise). Jittering reduces
visual miscues that result from the vertical and horizontal synchronization of
regularly  spaced  data.