However , traditionally the parameters used are slightly different .
For example , the three numbers that specify the body 's initial position , and the three values that specify its velocity will define a unique orbit that can be calculated forwards ( or backwards ) in time .
Traditionally the parameters used are slightly different .
For example , the three numbers that specify the body 's initial position , and the three values that specify its velocity will define a unique orbit that can be calculated forwards ( or backwards ) in time .