d.rast map_1
LIST=`g.mlist type=rast mapset=timeseries pat="map_*" | sort -t '_' -k 2 -n | tr '\n' ','| sed 's+,$++g'`
i.spectral -i rast=$LIST
This will search all maps in the mapset 'timeseries' which match have
the 'map_' prefix and order by a number following this prefix (day of the
year etc). The user is then asked to click into a map position and the
resulting pixel values of all matching maps are drawn in the gnuplot
output.