Prolog Tree Drawing Programs Compared:
"They all beat pencil and paper."

Prof. Ray C. Dougherty
New York University | Linguistics Department


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A Word on Tree Draw Programs

The NYU Vanilla and Lehner's tree drawing programs produce ASCII codes for the trees and can be sent to normal text files. For these programs, one could change the typeface (make it bigger or smaller; or change from Courier to Modern, or use Itallics or Old English script). The output, if in a file, could be included as text in a word processor document (Word,WordPerfect, etc.). The print stays neat and clear even in small font sizes on laser and inkjet printers. The code which draws the trees is Prolog Code and the trees can be drawn without leaving Prolog.

Kostko's and Vincent's tree drawing programs produce graphic images, like a picture or a photograph. They can be rotated, enlarged, shrunk, colored, etc. But you cannot change the type style or typeface since this is actually like a photograph of the text. It is not ASCII code. As shown below under Kostko' program, you can rotate, invert, etc. the image. This can sometimes be useful for printing negatives or for viewing the trees in three dimensions.

Vincent's program makes the sentence diagram fit one the screen no matter how big the sentence is. This causes the letters to change size depending on the size of the sentence. It is useful for working at a terminal and obtaining an overview of the tree. Kostko's program uses one size type and big sentences make big trees. Kostko's program is intended for pretty output of results. Kostko and Vincent submitted these programs as term projects in V61.0024.

Each program has its uses. The input format differs slightly between programs. See pages of the Beginner's Workbook in Computational Linguistics for illustrations.

The following shows how each drawing program handles the sentence:

The woman sees in the house.

1. The NYU Vanilla ASCII Tree Draw Program. (Prolog)

2. Christop Lehner's ASCII Tree Draw Program. (Prolog)

3. Oleg Kostko's Graphic Image .bmp Tree Draw Program. (DOS/Windows)

4. Jenner Vincent's Screen Image Graphic Tree Draw Program. (DOS/Windows)