[comment {-*- tcl -*- doctools manpage}]
[manpage_begin counter n 2.0.4]
[keywords counting]
[keywords histogram]
[keywords statistics]
[keywords tallying]
[moddesc   {Counters and Histograms}]
[titledesc {Procedures for counters and histograms}]
[category  {Data structures}]
[require Tcl 8]
[require counter [opt 2.0.4]]
[description]
[para]

The [package counter] package provides a counter facility and can
compute statistics and histograms over the collected data.

[list_begin definitions]

[call [cmd ::counter::init] [arg {tag args}]]

This defines a counter with the name [arg tag].  The [arg args]
determines the characteristics of the counter.  The [arg args] are

[list_begin definitions]
[def "[option -group] [arg name]"]

Keep a grouped counter where the name of the histogram bucket is
passed into [cmd ::counter::count].

[def "[option -hist] [arg bucketsize]"]

Accumulate the counter into histogram buckets of size

[arg bucketsize].  For example, if the samples are millisecond time
values and [arg bucketsize] is 10, then each histogram bucket
represents time values of 0 to 10 msec, 10 to 20 msec, 20 to 30 msec,
and so on.

[def "[option -hist2x] [arg bucketsize]"]

Accumulate the statistic into histogram buckets.  The size of the
first bucket is [arg bucketsize], each other bucket holds values 2
times the size of the previous bucket.  For example, if

[arg bucketsize] is 10, then each histogram bucket represents time
values of 0 to 10 msec, 10 to 20 msec, 20 to 40 msec, 40 to 80 msec,
and so on.

[def "[option -hist10x] [arg bucketsize]"]

Accumulate the statistic into histogram buckets.  The size of the
first bucket is [arg bucketsize], each other bucket holds values 10
times the size of the previous bucket.  For example, if

[arg bucketsize] is 10, then each histogram bucket represents time
values of 0 to 10 msec, 10 to 100 msec, 100 to 1000 msec, and so on.

[def "[option -lastn] [arg N]"]

Save the last [arg N] values of the counter to maintain a "running
average" over the last [arg N] values.

[def "[option -timehist] [arg secsPerMinute]"]

Keep a time-based histogram.  The counter is summed into a histogram
bucket based on the current time.  There are 60 per-minute buckets
that have a size determined by [arg secsPerMinute], which is normally
60, but for testing purposes can be less.  Every "hour" (i.e., 60
"minutes") the contents of the per-minute buckets are summed into the
next hourly bucket.  Every 24 "hours" the contents of the per-hour
buckets are summed into the next daily bucket.  The counter package
keeps all time-based histograms in sync, so the first

[arg secsPerMinute] value seen by the package is used for all
subsequent time-based histograms.

[list_end]

[call [cmd ::counter::count] [arg tag] [opt [arg delta]] [opt [arg instance]]]

Increment the counter identified by [arg tag].  The default increment
is 1, although you can increment by any value, integer or real, by
specifying [arg delta].  You must declare each counter with

[cmd ::counter::init] to define the characteristics of counter before
you start to use it.  If the counter type is [option -group], then the
counter identified by [arg instance] is incremented.

[call [cmd ::counter::start] [arg {tag instance}]]

Record the starting time of an interval.  The [arg tag] is the name of
the counter defined as a [option -hist] value-based histogram.  The
[arg instance] is used to distinguish this interval from any other
intervals that might be overlapping this one.

[call [cmd ::counter::stop] [arg {tag instance}]]

Record the ending time of an interval.  The delta time since the
corresponding [cmd ::counter::start] call for [arg instance] is
recorded in the histogram identified by [arg tag].

[call [cmd ::counter::get] [arg {tag args}]]

Return statistics about a counter identified by [arg tag].  The

[arg args] determine what value to return:

[list_begin definitions]
[def [option -total]]

Return the total value of the counter.  This is the default if

[arg args] is not specified.

[def [option -totalVar]]

Return the name of the total variable.  Useful for specifying with
-textvariable in a Tk widget.

[def [option -N]]

Return the number of samples accumulated into the counter.

[def [option -avg]]

Return the average of samples accumulated into the counter.

[def [option -avgn]]

Return the average over the last [arg N] samples taken.  The [arg N]
value is set in the [cmd ::counter::init] call.

[def "[option -hist] [arg bucket]"]

If [arg bucket] is specified, then the value in that bucket of the
histogram is returned.  Otherwise the complete histogram is returned
in array get format sorted by bucket.

[def [option -histVar]]

Return the name of the histogram array variable.

[def [option -histHour]]

Return the complete hourly histogram in array get format sorted by
bucket.

[def [option -histHourVar]]

Return the name of the hourly histogram array variable.

[def [option -histDay]]

Return the complete daily histogram in array get format sorted by
bucket.

[def [option -histDayVar]]

Return the name of the daily histogram array variable.

[def [option -resetDate]]

Return the clock seconds value recorded when the
counter was last reset.

[def [option -all]]

Return an array get of the array used to store the counter.  This
includes the total, the number of samples (N), and any type-specific
information.  This does not include the histogram array.

[list_end]

[call [cmd ::counter::exists] [arg tag]]

Returns 1 if the counter is defined.

[call [cmd ::counter::names]]

Returns a list of all counters defined.

[call [cmd ::counter::histHtmlDisplay] [arg {tag args}]]

Generate HTML to display a histogram for a counter.  The [arg args]
control the format of the display.  They are:

[list_begin definitions]
[def "[option -title] [arg string]"]

Label to display above bar chart

[def "[option -unit] [arg unit]"]

Specify [const minutes], [const hours], or [const days] for the
time-base histograms.  For value-based histograms, the [arg unit] is
used in the title.

[def "[option -images] [arg url]"]

URL of /images directory.

[def "[option -gif] [arg filename]"]

Image for normal histogram bars.  The [arg filename] is relative to
the [option -images] directory.

[def "[option -ongif] [arg filename]"]

Image for the active histogram bar.  The [arg filename] is relative to
the [option -images] directory.

[def "[option -max] [arg N]"]

Maximum number of value-based buckets to display.

[def "[option -height] [arg N]"]

Pixel height of the highest bar.

[def "[option -width] [arg N]"]

Pixel width of each bar.

[def "[option -skip] [arg N]"]

Buckets to skip when labeling value-based histograms.

[def "[option -format] [arg string]"]

Format used to display labels of buckets.

[def "[option -text] [arg boolean]"]

If 1, a text version of the histogram is dumped, otherwise a graphical
one is generated.

[list_end]

[call [cmd ::counter::reset] [arg {tag args}]]

Resets the counter with the name [arg tag] to an initial state. The
[arg args] determine the new characteristics of the counter. They have
the same meaning as described for [cmd ::counter::init].

[list_end]

[vset CATEGORY counter]
[include ../doctools2base/include/feedback.inc]
[manpage_end]
