# Gangle interactive index group selection, advance to next group

**URL:** <https://gromacs.bioexcel.eu/t/gangle-interactive-index-group-selection-advance-to-next-group/6303>\
**Category:** User discussions\
**Tags:** analysis-tools\
**Created:** [April 28, 2023, 2:55pm UTC](https://gromacs.bioexcel.eu/t/gangle-interactive-index-group-selection-advance-to-next-group/6303 "2023-04-28T14:55:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![aheim](https://avatars.discourse-cdn.com/v4/letter/a/91b2a8/32.png) [@aheim](https://gromacs.bioexcel.eu/u/aheim)\
**Post date:** [April 28, 2023, 2:55pm UTC](https://gromacs.bioexcel.eu/t/gangle-interactive-index-group-selection-advance-to-next-group/6303/1 "2023-04-28T14:55:17Z")

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GROMACS version: 2022-3  
GROMACS modification: Yes  
A low priority question since I have a workaround but:  
I [too](https://gromacs.bioexcel.eu/t/is-it-possible-to-compute-angle-between-two-rings-in-gromacs/4068) am attempting to measure the angle between rings. I’d like to use the `-n` option and select index groups interactively instead of using the selection syntax in the `-group1/2` flags.  
I ran into a slight hiccup: I cannot figure out the key sequence or command to inform the `gangle` that I have finished entering index groups for `group1` and now want to move on to `group2`.