Qxw and Crux: Frequently Asked Questions

What sort of grid can I construct with Qxw?

You can construct grids of any shape based on square cells. You can use blocks or bars, or a mix of the two, to separate words. The grid must fit within a 27-by-27 square.

What dictionary does Qxw use?

If no dictionary is specified using the command-line -d option, Qxw looks for the following dictionary files and loads the first one it finds:

• the file ukacd17.txt in the current directory
• the file /usr/dict/words
• the file /usr/share/dict/words
• the file /usr/share/dict/british-english
• the file /usr/share/dict/american-english

Note that on some more recent Linux distributions, the last of these is a version of the Moby word list. This is too comprehensive for many purposes, including many strings of characters that are not obviously words at all.

You can make Qxw use a different dictionary file with a command-line argument: qxw -d<filename>

Crux’s default dictionary is the file dict in the directory from which it is run.

Where can I find alternative dictionary files?

There are many freely-available word lists to be found on the Internet. Here are a couple of places to start looking:

• The UKACD
• Moby, an enormous public domain word list
• YAWL (Yet Another Word List)
• The Sourceforge word list page has many useful links

Do you have DOS/Windows 3.1/95/98/Me/NT/2000/XP/Vista/Solaris/... versions of the programs?

No; sorry. If you are interested in helping to port Qxw or Crux to a new operating system, please get in touch.

How about Mac OS X?

Matt Grime offers the folowing recipe for building from source under Mac OS X. I have not tested it, and you follow it at your own risk.

1. If not installed already, use Darwin Ports to install gtk2 (do not use jhbuild or similar):

sudo port install gtk2

2. If there are issues, remove outdated libraries with

sudo port uninstall outdated

and update all packages using

sudo port upgrade installed

following any command line instructions to link libs to the right place, and then try installing gtk2.

3. Make sure that pkgconfig is installed with

sudo port install pkgconfig

and then the source should compile cleanly.

Qxw running on Mac OS X is reported to be no more reliable than other X11 applications running on that operating system.

Why can’t I get your program to work under my distribution of Linux?

The binaries distributed are compiled for the Intel x86 architecture. These will only work on Intel and compatible (for example AMD) processors. You need reasonably up-to-date versions of GLib and GTK: try building from the source code on your own machine if that seems to be the problem. Otherwise, please contact me and I will try to help.

What is the format of Qxw’s dictionary file?

The dictionary is a plain text file, which means you can use standard text tools to create and edit dictionaries. Each line of the file should contain a word optionally followed by a numerical score for that word. The word and its score are separated by a space.

Qxw first assumes that the dictionary file is encoded in UTF-8 format. If when reading the file it determines that this is not the case, it tries again on the assumption that the file is encoded in ISO 8859-1 format.

Simple puncutation marks are stripped from words; ‘words’ containing digits or other symbols are ignored entirely. Accents are removed and all letters are converted to upper-case. Words may contain spaces, which are stripped. Words longer than 27 characters are ignored.

The score is a floating-point numerical value in the range -10.0 to +10.0. Negative scores will bias Qxw’s autofill function away from using the word, positive values will bias it towards the word. The score also determines the ordering of the feasible word list. If no score is given, a score of 0.0 (neutral) is assigned to the word.

If the same word happens to occur more than once in the file, its scores are added together, subject to the total remaining in the range -10.0 to +10.0. This means that it is possible to concatenate a basic dictionary not containing score information to a supplementary word list containing words (along with scores) which you particularly want to promote or demote. You would then end up with a dictionary file looking like this:

a
aardvark
abacus
.
.
.
zymosis
zymurgy
january +10
february +10
march +10
.
.
.
november +10
december +10

This will work as expected whether or not the month names also appear in the main list.

How do I convert an EPS file into GIF or PNG format so I can publish it on a website?

A command along the lines of

should do the trick.

This command can easily be modified to produce other bitmap formats such as PNG. It requires the ppmtogif program, which may not be included as standard in every distribution. Debian users may need to look in the package netpbm-nonfree rather than netpbm.

There are many commands available to process bitmap images, and the GIMP (GNU Image Manipulation Program) is a very powerful interactive image editing tool.

Note that Qxw can export grids in HTML directly.

Why does the HTML I have exported from Qxw not display correctly?

The HTML that Qxw produces requires that the browser support CSS (Cascading Style Sheets). Some older browsers do not support CSS fully. Many browsers print pages slightly differently from the way they appear on the screen, and some early versions of Firefox are rather poor in this regard.

Earlier versions of Qxw emit HTML that refers to two small image files, qpx0.gif and qpx1.gif, which were included with Qxw. You must ensure that there are copies of these files in the same directory as the HTML file. These files are not required for HTML produced by the current version of Qxw.

If you still experience problems with the compatibility of the HTML output, please contact me with the details. In particular I shall need to know which version of which browser you are using.

How does the grid filler work?

Qxw’s grid filler and Crux work in very similar ways. The essential idea is to explore the possible fills of the grid one letter at a time, trying to solve the trickiest parts of the grid first. When a letter is hypothesised for a particular cell, the implications of that choice are worked out and propagated around the grid. This is used to determine which cell is tried next.

What do Crux’s progress messages mean?

The counts show the number of different letters tried at each search depth.

What is the format of Crux’s dictionary file?

The dictionary file should contain one word per line. Only the characters ‘A’ to ‘Z’ and ‘a’ to ‘z’ are significant; Crux is not case sensitive in the dictionary file. White space separates words. If you wish to use a dictionary that contains phrases, any spaces between the words of a phrase should be removed first.