<html><head><title>[ACE] A The Meanings of ACE's output messages</title></head>
<body text="#000000" bgcolor="#ffffff">
[<a href = "chapters.htm">Up</a>] [<a href ="CHAP006.htm">Previous</a>] [<a href ="CHAP00B.htm">Next</a>] [<a href = "theindex.htm">Index</a>]
<h1>A The Meanings of ACE's output messages</h1><p>
<P>
<H3>Sections</H3>
<oL>
<li> <A HREF="CHAP00A.htm#SECT001">Progress Messages</a>
<li> <A HREF="CHAP00A.htm#SECT002">Results Messages</a>
</ol><p>
<p>
In this chapter, we discuss the meanings of the messages that appear
in output from the <font face="Gill Sans,Helvetica,Arial">ACE</font> binary, the verbosity of which is determined
by the <code>messages</code> option (see <a href="CHAP004.htm#SSEC018.1">option messages</a>). Actually our aim
here is to concentrate on describing those ``messages'' that are
controlled by the <code>messages</code> option, namely the <strong>progress</strong> and
<strong>results messages</strong>; other output from <font face="Gill Sans,Helvetica,Arial">ACE</font> is fairly
self-explanatory. (We describe some other output to give points of
reference.)
<p>
Both interactively and non-interactively, <font face="Gill Sans,Helvetica,Arial">ACE</font> output is <code>Info</code>-ed
at <code>InfoACE</code> level 3. To see the <code>Info</code>-ed <font face="Gill Sans,Helvetica,Arial">ACE</font> output, set the
<code>InfoLevel</code> of <code>InfoACE</code> to at least 3, e.g.
<p>
<pre>
gap> SetInfoACELevel(3);
</pre>
<p>
This causes each line of <font face="Gill Sans,Helvetica,Arial">ACE</font> output to be prepended with
``<code>#I </code>''. Below, we describe the <code>Info</code>-ed output observed when
each of <code>ACECosetTableFromGensAndRels</code>, <code>ACECosetTable</code>, <code>ACEStats</code> or
<code>ACEStart</code> is called with three arguments, and presume that users will
be able to extend the description to explain output observed from
other <font face="Gill Sans,Helvetica,Arial">ACE</font> interface functions. The first-observed (<code>Info</code>-ed)
output from <font face="Gill Sans,Helvetica,Arial">ACE</font>, is <font face="Gill Sans,Helvetica,Arial">ACE</font>'s banner, e.g.
<p>
<pre>
#I ACE 3.001 Sun Sep 30 21:45:39 2001
#I =========================================
#I Host information:
#I name = rigel
</pre>
<p>
If there were any errors in the directives put to <font face="Gill Sans,Helvetica,Arial">ACE</font>, or output
from the options described in Appendix <a href="CHAP00D.htm">Other ACE Options</a>, they will
appear next. Then, the next observed output is a row of three
asterisks:
<p>
<pre>
#I ***
</pre>
<p>
<strong>Guru note:</strong>
The three asterisks are generated by a ``<code>text:***</code>'' (see <a href="CHAP00D.htm#SSEC007.1">option text</a>) directive, emitted to <font face="Gill Sans,Helvetica,Arial">ACE</font>, so that <font face="Gill Sans,Helvetica,Arial">ACE</font>'s response can be
used as a sentinel to flush out any user errors, or any output from a
user's use of Appendix <a href="CHAP00D.htm">Other ACE Options</a> options.
<p>
Next, if the <code>messages</code> option (see <a href="CHAP004.htm#SSEC018.1">option messages</a>) is set to a
non-zero value, what is observed is a heading like:
<p>
<pre>
#I #--- ACE 3.001: Run Parameters ---
</pre>
<p>
(where <code>3.001</code> may be replaced be some later version number of the
<font face="Gill Sans,Helvetica,Arial">ACE</font> binary) followed by the ``input parameters'' developed from the
arguments and options passed to <code>ACECosetTableFromGensAndRels</code>,
<code>ACEStats</code> or <code>ACEStart</code>. After these appears a separator:
<p>
<pre>
#I #---------------------------------
</pre>
<p>
followed by any <strong>progress messages</strong> (progress messages only occur if
<code>messages</code> is non-zero; recall that by default <code>messages</code> = 0),
followed by a <strong>results message</strong>.
<p>
In the case of <code>ACECosetTableFromGensAndRels</code>, the <strong>results message</strong>
is followed by a compaction (<code>CO</code> or <code>co</code>) progress message and a
coset table.
<p>
<font face="Gill Sans,Helvetica,Arial">ACE</font>'s exit banner which should look something like:
<p>
<pre>
=========================================
ACE 3.001 Sun Sep 30 22:03:36 2001
</pre>
<p>
is only seen when running <font face="Gill Sans,Helvetica,Arial">ACE</font> as a standalone.
<p>
Both <strong>progress messages</strong> and the <strong>results message</strong> consist of an
initial tag followed by a list of statistics. All messages have values
for the statistics <code>a</code>, <code>r</code>, <code>h</code>, <code>n</code>, <code>h</code>, <code>l</code> and <code>c</code> (excepting
that the second <code>h</code>, the one following the <code>n</code> statistic, is only
given if hole monitoring has been turned on by setting <code>messages</code> < 0, which as noted above is expensive and should be avoided unless
really needed). Additionally, there may appear the statistics: <code>m</code> and
<code>t</code> (as for the results message); <code>d</code>; or <code>s</code>, <code>d</code> and <code>c</code> (as for the
<code>DS</code> progress message). The meanings of the various statistics and
tags will follow later. The following is a sample progress message:
<p>
<pre>
#I AD: a=2 r=1 h=1 n=3; h=66.67% l=1 c=+0.00; m=2 t=2
</pre>
<p>
with tag <code>AD</code> and values for the statistics <code>a</code>, <code>r</code>, <code>h</code>, <code>n</code>, <code>h</code>
(appears because <code>messages</code> < 0), <code>l</code>, <code>c</code>, <code>m</code> and <code>t</code>. The
following is a sample results message:
<p>
<pre>
#I INDEX = 12 (a=12 r=16 h=1 n=16; l=3 c=0.01; m=14 t=15)
</pre>
<p>
which, in this case, declares a successful enumeration of the coset
numbers of a subgroup of index 12 within a group, and, as it turns
out, values for the same statistics as the sample progress message.
<p>
You should see all the above (and a little more), except that your
dates and host information will no doubt differ, by running:
<p>
<pre>
gap> ACEExample("A5-C5" : echo:=0, messages:=-1);
</pre>
<p>
In the following table we list the statistics that can follow a
progress or results message tag, in order:
<p>
<pre>
--------------------------------------------------------------------
statistic meaning
--------------------------------------------------------------------
a number of active coset numbers
r number of applied coset numbers
h first (potentially) incomplete row
n next coset number definition
h percentage of holes in the table (if `messages'$ \< 0$)
l number of main loop passes
c total CPU time
m maximum number of active coset numbers
t total number of coset numbers defined
s new deduction stack size (with DS tag)
d current deduction stack size, or
no. of non-redundant deductions retained (with DS tag)
c no. of redundant deductions discarded (with DS tag)
--------------------------------------------------------------------
</pre>
<p>
Now that we have discussed the various meanings of the statistics,
it's time to discuss the various types of progress and results
messages possible. First we describe progress messages.
<p>
<p>
<h2><a name="SECT001">A.1 Progress Messages</a></h2>
<p><p>
A progress message (and its tag) indicates the function just completed
by the enumerator. In the following table, the possible message <code>tag</code>s
appear in the first column. In the <code>action</code> column, a <code>y</code> indicates
the function is aggregated and counted. Every time this count reaches
the value of <code>messages</code>, a message line is printed and the count is
zeroed. Those tags flagged with a <code>y*</code> are only present if the
appropriate option was included when the <font face="Gill Sans,Helvetica,Arial">ACE</font> binary was compiled (a
default compilation includes the appropriate options; so normally read
<code>y*</code> as <code>y</code>). Tags with an <code>n</code> in the <code>action</code> column indicate the
function is not counted, and cause a message line to be output every
time they occur. They also cause the action count to be reset.
<p>
<pre>
------------------------------------------------------------------
tag action meaning
------------------------------------------------------------------
AD y coset 1 application definition (`SG'/`RS' phase)
RD y R-style definition
RF y row-filling definition
CG y immediate gap-filling definition
CC y* coincidence processed
DD y* deduction processed
CP y preferred list gap-filling definition
CD y C-style definition
Lx n lookahead performed (type `x')
CO n table compacted
co n compaction routine called, but nothing recovered
CL n complete lookahead (table as deduction stack)
UH n updated completed-row counter
RA n remaining coset numbers applied to relators
SG n subgroup generator phase
RS n relators in subgroup phase
DS n stack overflowed (compacted and doubled)
------------------------------------------------------------------
</pre>
<p>
<p>
<h2><a name="SECT002">A.2 Results Messages</a></h2>
<p><p>
The possible results are given in the following table; any result not
listed represents an internal error and should be reported to the
<font face="Gill Sans,Helvetica,Arial">ACE</font> authors.
<p>
<pre>
result tag meaning
-------------------------------------------------------------------
INDEX = x finite index of `x' obtained
OVERFLOW out of table space
SG PHASE OVERFLOW out of space (processing subgroup generators)
ITERATION LIMIT `loop' limit triggered
TIME LIMT `ti' limit triggered
HOLE LIMIT `ho' limit triggered
INCOMPLETE TABLE all coset numbers applied, but table has holes
MEMORY PROBLEM out of memory (building data structures)
-------------------------------------------------------------------
</pre>
<p>
<strong>Notes:</strong>
Recall that hole monitoring is switched on by setting a negative value
for the <code>messages</code> (see <a href="CHAP004.htm#SSEC018.1">option messages</a>) option, but note that hole
monitoring is expensive, so don't turn it on unless you really need
it. If you wish to print out the presentation and the options, but not
the progress messages, then set <code>messages</code> non-zero, but very large.
(You'll still get the <code>SG</code>, <code>DS</code>, etc. messages, but not the <code>RD</code>,
<code>DD</code>, etc. ones.) You can set <code>messages</code> to 1, to monitor all
enumerator actions, but be warned that this can yield very large
output files.
<p>
<p>
[<a href = "chapters.htm">Up</a>] [<a href ="CHAP006.htm">Previous</a>] [<a href ="CHAP00B.htm">Next</a>] [<a href = "theindex.htm">Index</a>]
<P>
<address>ACE manual<br>Januar 2006
</address></body></html>
distrib
>
Mandriva
>
2010.0
>
i586
>
media
>
contrib-release
>
by-pkgid
>
91213ddcfbe7f54821d42c2d9e091326
>
files
>
321
