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+Optimize keyboard layout
+========================
+
+I'm sure you, too, know the history of the QWERTY keyboard, that was designed
+to avoid that too fast typists jammed mechanical typewriters. You would know
+also that the Dvorak layout is cosidered by many to be faster and more
+effective.
+
+When I tried to learn to use the Dvorak keyboard, a friend of mine asked me Why
+don't you write a program to measure your keyboard usage, and then obtain a
+personalized layout?. In a moment of crazyness, I decided to do just that.
+
+The first program is freq.pl, which reads the files given on the command line
+and produces a probability matrix, writing it into the file whose name is in
+the $MATRFN variable, default /tmp/freq.matr. Actually it sees the text as a
+Markov process over the characters with memory 1, and extracts the transition
+matrix. Note: the elements are frequencies, not probabilities. The optional
+normalization is left as exercise to the reader.
+
+The second program is freqdump.pl, which is probably useless. I've written it
+(three or four different versions) to have an idea about the frequencies. Give
+it a look if you want.
+
+The most useful program (I hope) is optkeyb.pl, which starting from the matrix
+(as usual, filename hardcoded) and the QWERTY layout searches by stochastic
+gradient descent a better layout. In other words, it calculates a value for the
+layout (sum over the pairs of keys of their distance times the frequency of
+that pair), then tries to exchange two random keys looking for a better result.
+To avoid local minima (there are a lot) it starts by randomly exchanging
+$PRE_SHUFFLE pairs, and if it doesn't find a better layout for $STARVATION
+tries it starts again, after having written the locally optimum layout at the
+end of the file /tmp/layouts. It uses curses and the corresponding Perl module
+Curses.pm.
+
+To avoid bad things, like numbers scattered between other keys, it's possible
+to set into the %locked hash the keys that must not be moved.
+
+To give yoy an idea of the results, after some hours of computation the best
+layout was:
+
+::
+
+    
+    ` 1 2 3 4 5 6 7 8 9 0 ; =
+       - x w h t s a l b y ' j q
+       z \ [ c i e r u p . ,
+        k v f d n o m g ] /
+    
+..
+
+
+
+Bear in mind I use a IBM U.S. keyboard, and where the q is, there's usally the
+backslash/pipe key, which is larger than the others, so I should have locked
+it...
+
+To have an idea of the optimization, the value relative to the QWERTY layout is
+10.190.280, for the one above is 6.797.370, meaning a 34% reduction in the
+space travelled by the fingers during writing.