1.4.2.1. - Retrieving Scans By Scan Number or File Position Number
Scans can be retrieved by entering either the scan number (option
+S, default) or the file position number (option
-S). Scan numbers are determined by the
#S lines in the file.
The file position number is the sequence position
of the scan in the file, irrespective of scan number.
Normally, the scan number and the file position number are the same.
When selecting by scan numbers, if there is more than one scan with the same number, the last one is retrieved. Specify which instance of a repeated scan to retrieve by using the scan.sub syntax. For example, selecting scan 10.3 retrieves the third instance of scan number 10.
Negative numbers count back from the end of the file and are always considered to be file position numbers. For example,
fn . -1will always return the last scan in the file. You can read in multiple scans by giving several scan numbers as arguments. You can read in a group of consecutive scans with
fn . 3-7 10-14The above reads in scans 3 through 7 and 10 through 14.