Tree has 13 options:
Tree processes the text in the files named on the command line, and the resulting text with the reformatted trees is produced on the standard output. If no file names are given on the command line, input text is assumed on the standard input.
% tree inputtextfile >outputtextfile
% tree <inputtextfile >outputtextfile
% tree -t old.tex >new.tex
A tree in a text is introduced by the command `\tree'.
(ex1) \tree (S(NP(John))(VP(runs)))
The formatted tree will be indented by the space that separated the `\tree' command from the left margin (8 spaces for the above example). The `\tree' command may be followed by the same options that can be given on the command line. In case of a conflict, an option given in the text overrides one given on the command line. Nodes need not have names, but if the root node has no name, you need an extra pair of enclosing parentheses if the daughters of the root are to be connected by lines:
(ex2) \tree ((((John))((runs))))
After any options, the `\tree' command must be followed by a tree. In the case of inappropriate options, or when the next non-whitespace character after the command and valid options is not a `(', the command is ignored (and it remains in the processed text).
(ex3) \tree - this line will remain unchanged
If what follows the command does begin like a tree, but does not have enough right parens to balance the left ones, an error is reported.
(ex4) \tree (S(NP(John)(VP(runs))) - a bad tree missing
a right paren
Trees contain node names and (sub)trees. The name of the node comes before any sub-trees; text after a sub-tree not in parentheses is treated as a comment and is discarded. Since placing text in this position is not an ordinary way of putting comments into a tree definition, unless the -q option is given, warning messages are issued when such text is found.
(ex5) \tree -q (a phrase composed of others(a phrase
(a)(phrase))
This is a comment.(composed) (of others
(of)(others)) )
Several trees can be placed side-by-side by giving no name to the topmost node:
(ex6) \tree ((S(John)(V(runs)(fast))) (==>)
(S(V(runs)(fast))(S(John)(does))))
Spacing and new lines are generally not significant, except that spacing between parts of a node name causes a space to be part of the name (only a single space appears for multiple blanks or tabs). As in TeX, the percent character introduces a comment which continues through the end of the line. (ex7) produces the same tree as (ex1) above:
(ex7) \tree (S % Comments like this
(NP % are skipped over.
(John)
)
(VP
(runs)
)
)
To include left or right paren as part of a node name, precede it with a back slash.
(ex8) \tree (NP (Det(John's \(genitive\)))
(N\([+count]\)(legs)) )
A blank may also be made part of a node name by preceding it with a backslash (but this is not usually necessary). It is not necessary to use `\\' to make backslash part of a node name, although it is possible, since this will produce a single backslash in the output. A percent sign is counted a comment character, as in TeX, so to include a percent that will print, use `\%'. When generating TeX code, tree will leave the backslash there, as well as the percent, so that TeX will print a percent.
The horizontal space separating subparts of a tree is by default two spaces. This can be varied by calling tree with the -g (for ``gap'') option, for instance:
% tree -g4 infile
gives twice the default gap. You might need to increase the gap when using TeX, because it's possible for node names to run into one another.
A node can be given a display attribute with a command of the form backslash plus capital letter. `\T' draws a triangle under a node name instead of a vertical or diagonal lines, and `\L' for `lexical' omits the vertical under a node with a single child. The triangle is for the common convention to indicate structure not given explicitly. Without the -u option, it is not actually a triangle, but rather a box with a vertical at the top. With that option, it is an outlined triangle or, if the -b option was given with a non-zero value, it is a filled triangle, with blackness determined by the number after -b. (This number is interpreted as a decimal fraction with higher values giving darker shades of gray; 8 is darker than 2, and 85 is just a tiny bit darker than 8.)
(ex9) \tree (\T S (every) (good boy)
(VP (\L V(does)) (\L A(fine)) ))
In this example, a triangle is drawn under the S-node, and the `does' and `fine' are placed immediately under the `V' and `A' with no connecting vertical line. (The `\L' command is also useful for piling up several lines of text to avoid using too much horizontal space - see the ptsample file for illustration.)
Other commands are `\I' for inverting a tree, and `\H' for designating a node as head of a branching constituent so that the mother node will be aligned over it. `\R' puts a vertical at the right of a node and aligns upper and lower parts of the tree with this vertical, so that the node name appears to the left of connecting tree lines. `\B' and `\B0'-`\B9' are ``bolding'' commands that vary the style of the connecting lines beneath a node.
There are two commands for getting related constituents on the same horizontal level. `\F' moves a node with everything under it down, if necessary, to get a subtree down to level of the lowest node found elsewhere in the tree. `\E' modifies the effect of `\F' commands by restricting the downward displacement to the lowest node found in the subtree with the its top node marked `\E'.
There is also the bare beginning of a facility for drawing discontinuous constituents. The line that would ordinarily connect a node with the mother above it can be omitted with the `\O' command. Alternatively, the line can be omitted with the `\P' command, but then the name is also not displayed (though the tree is formatted as though there were a name present). Drawing a new line to connect a node to a node other than its natural mother requires PostScript commands, so it can only be done when using the -u option (described below). You label the mother with `\M' and label the (presumably) discontinuous daughter with `\D'. A curvy line will then be drawn between the mother and the daughter. If you need to connect other pairs of nodes, you can add a single digit after the `\M' and `\D' (giving 10 more pairs of labels). Unfortunately, several daughters can be connected to the same mother in this way only when all the daughters save possibly one come lower in the tree than the mother or, if at the same level, to the right of the mother. It is not possible to connect more than one unnatural mother to a given daughter. Leaves cannot be unnatural mothers.
(ex10) \tree (S(PP\O\D(near)(him))(NP(John))
(VP\M(saw)(a snake)))
Here a line over `PP' is omitted and a curvy line drawn from the top of `PP', since it has the daughter label `\D', to a position under `VP', since it has the corresponding mother label `\M'.
The TeX code output with the -t or -u option is rather primitive, since tree uses a rough approximation for the widths of node names. The width of a node name is taken to be the number of characters in the name times the `en' space of the current font, the `en' space being half an `em' or `quad'. Each line of print making up the tree is assumed to be 12 points high when the current `ex' height is that of Computer Modern Roman at 10 points, and is adjusted proportionately for `ex' heights different from this.
The approximation for the width of names may be off by quite a bit when node names have a lot of capital letters, or when they contain TeX commands. To compensate for this, tree adds some extra space for names that have lots of caps, and it removes space taken up by TeX commands, on the assumption that TeX commands will not change the width of printed stuff (which assumption may easily be wrong, of course).
If you do put font changing commands into node names, it is not necessary to group them in braces to confine their effects to the node names, since tree adds braces around node names, anyway. Every line of a tree is a paragraph, so one way to control left indentation is to give `\parindent' an appropriate value. Page breaks are prevented within a tree, so if you have not provided enough vertically stretchable space around trees, you may get TeX underfull vbox error messages, or, in the case of a tree too long for a page, a fatal error.
The -u option works like the -t option, except that for right-side up trees, instead of having TeX draw horizontal and vertical rules, PostScript commands for diagonal lines are issued. Naturally, this method of obtaining slanty lines is going to work only if you have a PostScript printer. The PostScript code is stuck inside TeX special commands, and the dvi-file translator program is expected just to include this code in its PostScript output. (Not all PS drivers for TeX do this, or do it in the same way. If it's a problem, email Greg for a version of dvi2ps that behaves right.)
The thickness of diagonal lines is not varied with different
font sizes.
But you could change it
ad hoc
by including in the text a command of the form:
`\special{<num> setlinewidth}'.
Triangles over two or more nodes are not wide enough.
Lowering a node by enclosing it in multiple parentheses just extends the vertical line above it, causing a corner with the -u option. A curve would be nicer.
There are undocumented -d debug and -h help options.
Terminal nodes of inverted trees that are re-attached to empty nodes of a larger construction are not treated correctly by the `\R' command or the -R option.
A node name in the same row as a very high or deep name will have excessive white space above or below it. Fonts with small ex-heights have tree lines too close to the tops of capitals, and fonts with large ex-heights have them too far away.
Tree was inspired by a predecessor program written by Chris Barker, Linguistics Board at University of California, Santa Cruz, barker@ling.ucsc.edu