!! extract a 1d spectrum from 2d frame

!! 
$ vi obdef.dat


$ grep     obj_ obdef.dat  | awk '{print $2}'  > x
$ grep skydown_ obdef.dat  | awk '{print $2}' >> x
$ grep   skyup_ obdef.dat  | awk '{print $2}' >> x
$ grep  object_ obdef.dat  | awk '{print $2}' >> x

$ echo `cat x` | awk '{print "@@ subext {p1} "$1,$2,$3,$4,$5,$6,$7}' > se.prg



@@ se.prg



$ cp obdef.dat obdef.new
write/out obdef.new contains new parameters for object extraction

avera/col cut = obsky 6500,6600
set/gra yaxis=-100,100
plot cut