1STATIST(1) General Commands Manual STATIST(1)
2
6 statist - calculate Huffman distribution for freeze(1)
7
9 statist [ -gx... ]
10
12 The default table is tuned for both C texts and executable files (as in
13 LHARC). If you will freeze any other files (natural language texts,
14 databases, images, fonts, etc.) you can calculate the matching posi‐
15 tions distribution using the `statist' program, which calculates and
16 displays the mentioned distribution for the given file. It is useful
17 for large (100K or more) files.
18 Though the built-in position table is polyvalent, the tuning can
20 increase the compression rate up to one additional percent. (Observed
21 mainly on text files.)
22
24 statist [-g...] < sample_file
25 or
26 gensample | statist [-g...]
27 where `gensample' is a program generating some sample stream of bytes
28 similar to files to be frozen.
29 The -g and -x switches have the same meaning as for freeze(1) and may
31 be repeated.
32 You can also see the intermediate values and watch their changes by
34 pressing INTR key when you wish.
35 Note: If you use gensample | statist , remember that INTR influence
37 BOTH processes !!
38 The results have the following format:
39 n1 n2 n3 n4 n5 n6 n7 n8 (uncertainty = x)
40 Average match length: xx.yy
41 Percentile 99.9: p999
42 Percentile 99.5: p995
43 Percentile 99.0: p990
44 Percentile 97.0: p970
45 Percentile 95.0: p950
46 Percentile 90.0: p900
47 Percentile 80.0: p800
48 Percentile 70.0: p700
49 Percentile 50.0: p500
50 Sigma: xx.yy
51 Here n1 - n8 are values of the calculated position table elements,
53 uncertainty is a number which denotes validity of given results (non-
54 zero values of uncertainty indicate that the results may be unusable).
55 Other values (average match length, percentiles and sigma) are FYI
56 only.
57 You may create the /etc/default/freeze file (if you don't like
59 /etc/default/ directory, choose another - in MS-DOS it is FREEZE.CNF in
60 the directory of FREEZE.EXE), which has the following format:
61 name = n1 n2 n3 n4 n5 n6 n7 n8
62 (name must start in column 1). For example:
63 ---------- cut here -----------
64 # This is freeze's defaults file
65 russian=0 0 1 2 6 20 31 2 # The sample was mailx.lp (Russian)
66 english=0 0 1 2 7 16 36 0 # The sample was gcc.lp (English)
67 # End of file
68 ---------- cut here -----------
69 If you find values, which are better THAN DEFAULT both for text (C pro‐
71 grams) and binary (executable) files, please send them to me.
72 Important note: statist.c is NOT a part of freeze package, it is an
74 aditional feature.
75
78 freeze(1), melt(1), fcat(1)
79
81 Huffman tree has more than 8 levels, reducing...
82 Self-explanatory, but sometimes reducing falls into infinite
83 loop.
84 xxxK
85 Progress indicator is written after each 4K of a file pro‐
86 cessed.
87
89 Sometimes use of the results with uncertainty = 1 (on a file) gives
90 compression rate worse than default but use of the results with uncer‐
91 tainty = 13 (on other file) works quite good.
92 Found bugs descriptions, incompatibilities, etc. please send to
94 leo@s514.ipmce.su.
95 local STATIST(1)