old_index

Format:

old*_index( scan_id)

Result:

Number

Description:

The old index of a SCAN is only used in the display routine and only if the interactive mode has been switched off (SET INTER OFF). In this case the display routine updates those points which are between the old index and the current index. This function returns the number of points that are already on the screen. It can also be used to set the old index.

e.g.:

SPECTRA> read bpu1

SPECTRA> * = old_index(bpu1)
0

SPECTRA> display

SPECTRA> * = old_index(bpu1)
222