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Vista tutorial
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Vista is one of a number of "do it all" astronomy reduction programs
such as AIPS or Figaro or IRAF.  It differs somewhat from reduction
suites such as imcat which use the Unix shell as glue between a
toolkit of utilities, but the fundamental capabilities are similar.
There are at least two versions of Vista in use, "Lick Vista" or the
"One and True Vista", and a version of "Vista" which split off in 1986
and which I have evolved forward.  Unfortunately the schism has become
quite deep and it is no longer straightforward to bridge the gap.
Equally unfortunate is the capital "V" in Vista, but it has become a
historical artifact which can not be changed.

There are two basic ways to use Vista: interactively or as a shell
command.  In the former mode you type things at Vista and it executes
them.  In the latter mode you type "Vista" followed by the name of a
procedure and (perhaps) some other arguments and it does the work
specified and terminates.  Since the shell command mode is essentially
identical to interactive mode, with the procedure providing the input
commands, I'll describe the former mode first.

First some Vista basics.  Vista maintains 32 image buffers into which
data can be read, numbered 1-32.  These buffers are labelled by their
number.  All images are taken to be two dimensional, even though one
dimension may be 1.  Vista maintains a set of numerical variables and
string variables which can be used in place of literal arguments and
which can be used for arithmetic calculations.  Vista can execute
lists of commands from disk files, called procedures.  These
procedures allow branching constructs and can be nested, but
unfortunately do not offer any means of passing arguments.  All
inter-process communication must be via variables (which all have
global scope).

The basic syntax of a Vista command is a command, followed by
arguments, followed by modifiers.  The arguments depend on the command
and various commands may have different actions depending on the
number of arguments present.  The modifiers are all of the form
"KEYWORD=VALUE" where the KEYWORD is an adverb specific to the
command, the "=" marks the end of the adverb, and the VALUE can be a
variety of possibilities.  There is no whitespace allowed in a 
"KEYWORD=VALUE" combination unless it is quoted with single quotes.

When Vista is started it responds with a ">>" prompt indicating that
it is ready to accept commands.  



on some of the more common things which you might do