The position on the reference sequence from which to start this coordinate system. The first base on the reference sequence is position 1 and there is no zero position on the reference sequence. The default start position is position 1 (the first base on the reference sequence).

For example, if the reference sequence is AGCTGTAACGT, and the startPosition is 5, then position 1 in this coordinate system is mapped to position 5 on the reference sequence, which is the second "G" in this reference sequence.

If the startPosition is -4, then position 5 in this coordinate system is the first "A" in this reference sequence. Note that it would be an error to report anything that is off the reference sequence. In this example, anything before position 5 would be invalid.

Flags whether this coordinate system has a zero:

• true
• false

For example, if the reference sequence is AGCTGTAACGT, and the startPosition is 5, and hasZero is true, then position -2 is mapped to position 2 on the reference sequence, which is the first "G" on the reference sequence. If hasZero is false, then position -2 is mapped to position 3 on the reference sequence, which is the first "C" on the reference sequence.