An arrangement of data such as shown below is called a report.
Time Elongation of R.A. Dec.
(utc) Mars (degrees) (degrees)
(degrees)
===================================================================
1991 JAN 01 00:00:00.0 137.37 55.0480 21.9656
1991 JAN 15 00:00:00.0 124.23 56.1913 22.2655
1991 JAN 29 00:00:00.0 113.15 59.5303 22.9024
1991 FEB 12 00:00:00.0 103.61 64.5064 23.6961
1991 FEB 26 00:00:00.0 95.20 70.6984 24.4673
1991 MAR 12 00:00:00.0 87.64 77.7730 25.0608
1991 MAR 26 00:00:00.0 80.71 85.4918 25.3570
1991 APR 09 00:00:00.0 74.28 93.6486 25.2694<
1991 APR 23 00:00:00.0 68.24 102.0850 24.7425
1991 MAY 07 00:00:00.0 62.53 110.6585 23.7505
1991 MAY 21 00:00:00.0 57.07 119.2652 22.2909
1991 JUN 04 00:00:00.0 51.83 127.8227 20.3835
1991 JUN 18 00:00:00.0 46.77 136.2862 18.0612
More formally, a report is a tabular arrangement of the values of a
collection of functions of time. The values within a row all correspond to th
to the same function. In addition, the epochs increase as you read down the
columns. The functions are not necessarily numeric functions. (For example
you might have a ``boolean'' function that states whether or not an object is
visible as a function of time.)
The PERCY system provides a report generation capability that allows you to easily see information about various aspects of the geometric state of the solar system.
The system allows you to present this information in units and formats that are best suited to your needs.
The columns of a report (the functions of the report) are called the report's
entries. These are defined using the NEW ENTRY command. The basic syntax of
this command is:
NEW ENTRY @name DESCRIPTION (1:)@wordThe name you choose should be one that is easy to remember. For example, if you want to create an entry that gives the angular separation between Io and Europa you might issue the following command
NEW ENTRY SEP_IO_EUROPA DESCRIPTION SEPARATION ...The list of quantities that can be specified in an entry are given here (The syntax for the various descriptions and information on setting the units and format with which entries are displayed is provided in the chapter NEW ENTRY later in this command reference.)
ANGULAR RATE APPARENT DIAMETER FRAME @framename @coordinate or @coordinate rate CARTOGRAPHIC @coordinate or @coordinate rate CENTRAL MERIDIAN LONGITUDE DISTANCE BETWEEN DISTANCE OF DISTANCE RATE BETWEEN DISTANCE RATE OF ECLIPSE ELONGATION NORTH POSITION ANGLE OCCULTATION ORBITAL LONGITUDE PENUMBRAL ECLIPSE PHASE PLANETOCENTRIC @coordinate or @coordinate rate PLANETOGRAPHIC @coordinate or @coordinate rate SEPARATION SOLAR POSITION ANGLE TIME TRANSIT UMBRAL ECLIPSE
A report is specified by a collection of entries to evaluate and the epochs
at w in the report. This is done with the NEW REPORT command. Its syntax is:
NEW REPORT @name ENTRIES (1:)@entryThe order in which the entries appear in the definition corresponds to the left-to-right order with which they will appear in reports. Also note that there are no default entries. If you want time to appear in reports you generate, you must supply an entry that is defined to be the TIME quantity.
The entries that you specify as belonging to this report do not need to be defined when you define the report. They must, of course, be define before you generate a report.
The second step in creating a report is specifying the epochs at which the
report's various entries should be evaluated. This is done with the GENERATE
REPORT command. There are two ways to do this. You can specify an interval of
time over which the entries of the report should be evaluated and a frequency
with which they should be evaluated. The syntax for this is:
GENERATE (0:1){ SMART } REPORT @report (3:8){ FROM @calendar
| TO @calendar
| EVERY @number
| @options
.
.
.
}
You can also specify a schedule over which the entries should be evaluated
and a frequency with which they should be evaluated.
GENERATE (0:1){ SMART } REPORT @report (2:7){ OVER @schedule
| EVERY @number
| @options
.
.
.
}
For more details about this command see the chapter GENERATE REPORT later in
this manual.
As you can see from the above, you can create a wide variety of reports.
However, setting up a report requires a bit of work. For this reason, there
are safeguards built in to the report subsystem so that you will not
accidently corrupt the report once you've defined it. To modify a report you
must tell the program to forget some aspect of it and then redefine the
forgotten aspect before generating the next report. For example suppose you
had previously issued the command:
NEW REPORT DATA ENTRIES TIME SEPARATION RATE;and you decided that you needed to modify the definition of the entry SEPARATION. To do this you must tell the program
FORGET ENTRY SEPARATION; NEW ENTRY SEPARATION DESCRIPTION ... or simply NEW! ENTRY SEPARATION DESCRIPTION ...Similarly, if you decided that the report should also include the entry DIAMETER you would need to issue the following commands.
FORGET REPORT DATA; NEW REPORT DATA ENTRIES TIME SEPARATION RATE DIAMETER; or NEW! REPORT DATA ENTRIES TIME SEPARATION RATE DIAMETER;See the chapter FORGET for more details on the FORGET ENTRY and FORGET REPORT commands.