Map Files

 To get data into the map, the command is add-to-map. This takes the spectrum in the X register and puts it in the map at the correct cell position. The first point you put in defines where the map centre will be (using the source coordinates and offsets), if you left that to be defaulted when you defined the map file setup with o-map; hence it doesn't matter which map point you first put in the map. There is also a delete-from-map for removing data from the map. If you want to see a listing of what is in the map do list-map. If you want to take a spectrum out of a map to look at it or to do some other operation on it, use get-spectrum-from-map. And if you have gaps in your map, you can do interpolate-map and SPECX will try to fill in the holes.

So, here is the command file I used to add the spectra into the above map file:

! map s140_core
do n 1 143
r-g-d\17\n\
r-g-d\18\n\;ave
r-g-d\19\n\;ave
r-g-d\21\n\;ave
r-g-d\22\n\;ave
r-g-d\23\n\;ave
r-g-d\24\n\;ave
das-merge\#\n\
drop 1190 220
f-p-b\-170 -150\-130 -110\^D\2\;sub
a-t-m
enddo

In this case the map was made in the raster `on-the-fly' mode. Because the integration time is limited to a few seconds in this case, the integration time per point was built up by making the same map 7 times, with calibrations before each scan, and a pointing part way through the series of maps. Hence I ended up with observations 17 thru 19 and 21 thru 24 inclusive. Each one consisted of 143 spectra (on a grid of 13 by 11 points). Hence the `do loop' runs through each map point (143 times) (a) averaging the appropriate subscans together, (b) merging the subbands together, (c) chopping off the unused part of the spectrum, (d) fitting a quadratic baseline, and (e) adding the result to the map. To save time the screen display was not turned on. One can also do this kind of operation effectively with the read-gsd-raster and merge-files commands - see Section .

This file illustrates some more points about command file syntax.

• Comment lines can be inserted by starting the lines with !.
• The `n' in the das-merge command inhibits subband offset adjustments; the `#' is a `placeholder' for the default channel drop.
• Two regions are chosen either side of the line emission for the polynomial fit. Note the method, using ^D (or ^Z), of terminating input to questions which have a larger number of possible answers than you need.

You may well find yourself wanting to replace all or part of your map subsequently. SPECX can be told to allow this, or not, using the set-map-access command. Thus:

>> s-m-a
Replace existing map spectra? (Y/N) [N] y
Maximum distance (pixels) from nearest gridpt? [   0.3]
..

Note that it is possible to set the positional tolerance of grid positions versus observed positions. The default is 0.7 pixel, but I prefer it tighter than that.