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help()

Usage:
help(topic [, allfiles:T])
help(topic1, topic2, ... [, allfiles:F])
help(Topic:Subtopics), Topic the name of a topic, Subtopics a CHARACTER
  scalar or vector naming subtopics of Topic
help(Topic, subtopic:Subtopics)
help(Topic, subtopic:"?")
help(index:helpfilename), CHARACTER scalar helpfilename
help(Pattern) where Pattern has form "start*", "start*end", or "*mid*",
  "start*mid*", ...
help(news [,allfiles:T]), help(news:yymmdd1 [,allfiles:T]) or
  help(news:vector(yymmdd1, yymmdd2) [,allfiles:T]), where yymmdd1 and
  yymmdd2 are integers like 990103, 19990103, 000717 or 20000727
help(key:KeyName [keywords]), where KeyName is a CHARACTER scalar or
  "?" (scans only current help file)
help(topic [,subtopic:Subtopics] , file:fileName or orig:T or alt:T),
  CHARACTER scalar fileName (scans only one help file)



Keywords: general
help() with no argument will print a short message giving some of the
help() and gethelp() options.

help(topicname) and help("topicname") lists help information on the
named topic.

help(topicname, subtopic:"subtopic_name") does the same, but lists only
the information in the named subtopic.  If topicname has no more than 10
characters, help(topicname:"subtopic_name") does the same.

You can print several subtopics by, for example, help(topicname,
subtopic:vector("usage", "examples")).

help() returns an "invisible" LOGICAL scalar whose value is True only
when at least one topic requested was found.  The value may be assigned
or tested but will not be printed automatically.  See topic
'variables:"invisible"'.

Files named in pre-defined CHARACTER vector HELPFILES are searched until
the topic is found.  This is done by repeated calls to gethelp(), which
scans only one file at a time.

By default, when help is requested on only one topic, the search stops
the first time the topic is found in a file.  To force scanning all
files, use keyword phrase 'allfiles:T'.

help(topic1, topic2, ...) requests help on several topics at once.  You
cannot use keyword 'subtopic' when there is more than one topic, but any
argument can be of the form topicname:"subtopic_name".

In this case, by default, all the help files are scanned, which can take
a noticable time.  If you know all the topics are in a single file, you
can save a little waiting time by using 'allfiles:F' as an argument.

help(index:helpfilename), where helpfilename is a quoted string or
CHARACTER scalar identifying one of the help files named in HELPFILES
prints the index topic in that file.  In particular,
  Cmd> help(index:HELPFILES[3])
prints the index of the file whose name is in the third element of
HELPFILES.

If helpfilename doesn't exactly match any name in HELPFILES (ignoring
case), various matches are attempted using the wild card characters '*'
and '?'.  Thus help(index:"design.hlp") and help(index:"design") both
print the annotated index of design.hlp.

No other arguments or keywords can be used with 'index'.

Examples:
  Cmd> help(anova); help(macros); help("break")
  Cmd> help(break); help(transformations) #now work; previously didn't
  Cmd> help(regress, usage:T) # same as usage(regress)
  Cmd> help(stepsetup, subtopic:"example")# or help(stepsetup:"example")
  Cmd> help(tsplot:vector("usage","example"))
  Cmd> if (!help(foo,silent:T)){print("No help on topic foo")}
  Cmd> help(index:"math")

You can reset the current help file to any particular file in HELPFILES
by
  Cmd> help(file:HELPFILES[I]) # 1 <= I <= length(HELPFILES)

On other usages of help(), the current help file is either not changed
or is changed to the last file searched.

  When no help is found or when there are several topics without all:F,
  the current help file is not changed.

  When there are several topics with all:F or a single topic, and at
  least one topic is found, the file containing the found topic becomes
  the current help file.

  Regardless of the number of topics, when reset:T is an argument, the
  current help file is not changed.

                              Topic 'news'
help(news) lists in reverse chronological order news items about
MacAnova starting with the most recent entry back for three months.

help(news:vector(Date1,Date2) [,scrollback:T] [,all:T]), where Date1
and Date2 are numbers of the form yymmdd or yyyymmdd, lists in reverse
chronological order news items about MacAnova development dated between
Date1 and Date2.  For example, help(news:vector(991201,0000131)) and
help(news:vector(19991201,20001230)) list all news items dated in
December, 1999 or January, 2000

help(news:Date) lists all news items on or after Date.  For example,
help(news:000101) and help(news:200000100) list all news items on or
after January 1, 2000.

help(news:0) lists all available news items.  This will produce many of
lines of output and is not recommended.

You can use 'scrollback:T' with all these ways to read news topics.

By default, when looking for news topics, only file HELPFILES[1]
(usually "macanova.hlp") is scanned.  If you include 'all:T' as an
argument, all files in HELPFILES are searched for news items.

HELPFILES is a CHARACTER vector initialized when MacAnova starts up to
contain all the standard help files except "userfun.hlp".

help() uses HELPFILES as a "circular" list.  If the current help file is
in the list, than the search starts with that file and wraps back to
HELPFILES[1] if necessary.  If the current help file is not in that
list, then the current help file is scanned, followed by the files named
in HELPFILES.

You can use macro addhelpfile() to add a file name to HELPFILES.  For
example, addhelpfile("mymacros.hlp") and addhelpfile("mymacros.hlp",T)
add "mymacros.hlp" at the start and end of HELPFILES, respectively.

You can use gethelp() keywords 'file', 'orig', 'alt' and 'key', but in
that case only the current help file is scanned, not the files in
HELPFILES.

help() is implemented as a macro which invokes gethelp().

NOTE: Prior to Version 4.12, function gethelp() was named help() and
there was no macro named help().

See gethelp(), getusage() and usage().


Gary Oehlert 2003-01-15