.sh 1 "EXTINCTION ROUTINES " 12


.sh 2 "Introduction "
.pp
The Extinction analysis is a least squares fit of a straight line
to the base 10 logarithm of the data versus airmass for each
channel.  The intercept and slope of the line, along with a goodness
of fit (correlation coefficient), are stored for later extinction
corrections with objects observed.  The Extinction routines are
accessed from Program Operations by typing
.ul
S.
The screen will then list available commands on the CRT.


.sh 2 "Starpack List and Display "
.pp
Type
.ul
D
to list the starpack by title.  You will then be instructed to
input a file number (1 to 50) or type the number 0 to list all
starpacks in the starpack file.  Typing a number (1 to 50) will
read that starpack into memory so that it can be displayed (see
section 12.4).  If zero was typed, the last starpack listed is in
memory (assuming there is no I/O error).  Note:  If you have just
created a new starpack, do not list the starpack file as this
writes over the starpack in memory.  Note that, when reading a
starpack from disk, you cannot do airmass versus log intensity
plots since this information is not stored in the starpack.  It
is only stored in memory after an extinction calculation.  In
order to do these plots or deletion and restoraton of runs and
channels (section 12.5), you must recreate the starpack from
scratch using the files in the history.


.sh 2 "Extinction Calculation "
.pp
Type
.ul
C
to perform extinction calculations.  The computer then asks the
user for up to 20 files for extinction calculations.  The files
are input by typing in the file ID (V, W, or D) and the file
numbers (the devices U and Y have not been expanded into this
routine yet).  The program is designed so that the user can type
on one line as in the example:

        W12 13 14 15 16V1 2 3 D4 5 6C.

Typing the file ID and then a string of numbers after the ID
causes the program to store the string of numbers along with that
file ID.  When all files have been typed in, the user types
.ul
C
to indicate the finish.  More than one line (at 80 characters per
line) may be used.  Note:  At the beginning of a new line, a file
ID must be typed; otherwise, erroneous file numbers will be
stored. After typing in the files, the user is asked to type in a 24
character title for the starpack.  After storing the title, the
computer will read in the files and list the titles on the CRT,
then calculate the extinction values (it takes a couple of
minutes), and display the slopes in a CRT plot.  At this point in
extinction calculations, all the data is stored and extinction
coefficients have been calculated, but the starpack has not been
written to the starpack file.  The user should look over the
calculations using the CRT plot and then write the starpack on
drum or disc (see below).
.pp
Possible deviations from normal operation:
.pp
If the revolutions in each file are not the same, the files whose
revolutions differ from the first file read in are flagged.  If
a file ID has not been included, a tape reading error is
encountered, the list of options is displayed, and the user must
begin again.


.sh 2 "CRT Plot "
.pp
Since the extinction coefficients are in 3 arrays (slopes,
intercepts, and goodness of fit), they are displayed one at a time
on the CRT.  When the plot routine is entered [automatically from
extinction calculation or by typing P (for plot) from extinction
commands], the slopes are displayed.  The scale can be changed by
typing
.ul
C,
the intercepts can be plotted by typing
.ul
I,
and the goodness of fit plotted by typing
.ul
G.
The slopes can then be plotted again by typing
.ul
S.
A lineprinter plot can be made of either slopes, intercepts, or
goodness of fit by typing
.ul
P
(note the lineprinter must be assigned).  To exit the plot
routines, type
.ul
E
or
.ul
X.
Both these exits are the same since there are no pending commands.


.sh 2 "Airmass Versus Log Intensity Plots and Deletion "
.ti 5
.ul
and Restoration of Runs and Channels
.pp
To investigate the scatter in the data and the fitted line, the
airmass versus log intensity must be plotted.  To improve the fit,
entire runs or single channels must be deleted (and restored).
Typing
.ul
T
will call this routine.  The program will then ask for a channel
number (with which an airmass versus log intensity plot is to be
made) or type
.ul
D
to delete runs and channels or
.ul
R
to restore runs and channels.
.pp
Up to 10 channels in each run can be deleted, or the entire run
can be deleted.  Since up to 20 files can be used to calculate
extinction, this routine refers to the files as run numbers 1 to
20 in the order that they were typed in by the user.  To delete a
run, type the run number and 0.  The system then asks for N channel
numbers to be read in.  The whole procedure can be repeated until
the user has finished deletions.  A least squares fit is done in
this routine, and the routines list of options is displayed upon
completion.  The least squares fit takes a couple of minutes.
.pp
Selecting restoration causes the display of an array of numbers
that is 12 wide and 20 high.  The left-hand column is the run
number, the column next to this gives the number of channels
deleted or, if this number is -1, that run has been deleted.  To
restore a run, type in the run number and zero; to restore a
channel, type in the run number and the channel number.  This
process can be repeated, if necessary, and the array can be plotted
out again showing any changes.  When restoration is complete, a
least squares fit is applied, and the routines list of options is
displayed.  The least squares fit takes a couple of minutes.  To
exit this routine, type E.
.pp
Note that no history is kept of runs and channels that are
deleted or restored.  There is a 592 character manual history
(section 12.6) for any notes or listing runs and channels which
have been deleted.


.sh 2 "Writing a Starpack "
.pp
After extinction calculations are finished, the starpack is
stored in memory but is not written to disc (to the starpack
file).  This is not done automatically because the user must look
over the data and decide whether he wants to delete runs or
channels or whether or not the starpack is any good at all.  Thus,
the user must remember that he has just performed an extinction
analysis and that the starpack must be written to the starpack
file.  (If you have been able to keep the slightest attention
while reading this manual, you will be able to remember when you
have finished an extinction analysis).  To write a starpack to
the starpack file, type
.ul
S.
You will then be asked for the file number (1 to 50).


.sh 2 "Starpack Manual History "
.pp
There is 592 character (8 lines at 74 characters per line) manual
history for special notes or listing runs and channels which have
been deleted.  Type
.ul
M
from the extinction routines section.  You will then be asked to
type in the line number or zero for all lines or
.ul
E
to exit the routine.
.bp


.sh 1 "GOULD PLOT ROUTINES "


.sh 2 "The Gould Plot Routines "
.pp
The Gould 5200 plot routines are designed to provide nearly all
types of plotting capability.  Plots can be in wavelength space,
energy space (energy increasing to the right), reverse energy
space (energy increasing to the left), or linear space with your
own label.  The vertical scale can be either linear or
logarithmic with the label selected from a list or typed in by
the user.  Text can be inserted at any angle on the plot.  There
are many options for controlling the type of plot.  The plot is
built up on the disc as a binary image containing 5 x 10 bits.
The resolution of the plot is 200 lines per inch.  Each plot
takes 6 to 8 minutes or more depending upon the number of
vertical lines.  If you have 120 channels with error bars that stretch from
the lower to the upper limit of the graph, the plot will take
about 25 minutes!  This is because the disc access is by
horizontal line.  Thus, to "draw" a vertical line takes many
(several hundreds) disc I/O's while a horizontal line may take only
2 I/O's.  The plot routines are called from Program Operations by
typing
.ul
P.


.sh 2 "Plotting Space Type "
.pp
Upon entering the Plot routine, the plotting space options are
given.  Type
.ul
W
to plot in wavelength space,
.ul
N
to plot in energy space (energy increasing to the right),
.ul
R
to plot in reverse energy space (energy increasing to the left),
or
.ul
Y
to type in your own horizontal axis label (the plot will be
linear).  If you type
.ul
Y,
you will be asked to type in the horizontal axis label (24
characters).  Here you might type:
.ul
TIME (SECONDS)
or whatever your data corresponds to.  Thus, you may do any kind
of one dimensional array processing you wish.
.pp
.ul
User selected wavelength limits:
You may select the wavelength limits for the plot, regardless of
the wavelength files.  When you type in the "W" for wavelength
space (or N, R, or Y), also type (on the same line) the minimum
and maximum wavelengths for the plot.  Type in wavelengths for
energy space also.  Example:
.l(

        "W 0.325        2.60"
        "N 0.325        2.60"
        "R 0.325        2.60"
        "Y 0.325        2.60"

.l)

The actual limits on the plot will be 2% greater of the range
(maximum-minimum) on each side (see section 13.5 for details).
.pp
The left bound is then minimum minus 2% of greater of the
maximum-minimum range, and the right bound is the maximum plus 2%
of the maximum-minimum range.
.pp
To exit the plot routine, type
.ul
E
or
.ul
X.
If you choose a space, the program will proceed to the
vertical axis label.


.sh 2 "Vertical Axis Label "
.pp
Five vertical scale labels are displayed for you to select.  They
are numbered 1 to 5.  To select one of these, type in the number.
If you wish to type in your own label, type
.ul
6,
and you will be instructed to type in the label (60 characters,
maximum).  If you wish to plot the vertical axis in log (base 10)
space, type
.ul
7,
and you must type in your own vertical axis label.  The program
will then proceed to the Delete From All Spectra section.  Type
.ul
E
or
.ul
X
to return to the beginning (section 13.2).


.sh 2 "Delete From All Spectra "
.pp
If, from all the spectra you are going to plot, you wish to delete
one or more channels common to all, type
.ul
D.
You will then be instructed to type in the channels which will be
deleted from all spectra to be plotted.  At least one space should
be left between each pair of channels, and more than one line can be
used for input.  All 256 channels may be deleted if desired.  When
you are through, type
.ul
C
to continue to the scale section.  Type
.ul
E
or
.ul
X
to return to the beginning (section 13.2).  When typing in a
sequence of channels, you may give the beginning channel, a
.ul
T,
and the end channel; for instance, to delete channels 1, 2, 3, 4,
5, 6, 7, 8, 15, 16, 17, 23, and 24, type
.ul
DIT8 15T17 23 24C.


.sh 2 "Scale of Plot "
.pp
The vertical scale of the plot is selected by the user.  Type in
the lower and upper bound of the plot.  The plot size is 19
centimeters (vertical axis) and 23.7 centimeters (horizontal
axis) for the data plot area.
.pp
If your data is to be plotted in log space on the vertical axis,
the lower and upper bound should be input as ordinary numbers.
The program will convert the scale limits and data to logs.  The
scale is then labeled as the log of the number.  Type
.ul
E
or
.ul
X
to return to the beginning of the plot routines (section 13.2);
otherwise, the program will go to the file input section.
