# counter(n) 2.0 counter "Counters and Histograms"

## NAME

counter - Procedures for counters and histograms

## SYNOPSIS

package require Tcl 8
package require counter ?2.0?

::counter::init tag args
::counter::count tag ?delta? ?instance?
::counter::start tag instance
::counter::stop tag instance
::counter::get tag args
::counter::exists tag
::counter::names
::counter::histHtmlDisplay tag args

## DESCRIPTION

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

::counter::init tag args
  This defines a counter with the name tag. The args determines the characteristics of the counter. The args are
  -group name
    Keep a grouped counter where the name of the histogram bucket is passed into ::counter::count.
  -hist bucketsize
    Accumulate the counter into histogram buckets of size bucketsize. For example, if the samples are millisecond time values and 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.
  -hist2x bucketsize
    Accumulate the statistic into histogram buckets. The size of the first bucket is bucketsize, each other bucket holds values 2 times the size of the previous bucket. For example, if 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.
  -hist10x bucketsize
    Accumulate the statistic into histogram buckets. The size of the first bucket is bucketsize, each other bucket holds values 10 times the size of the previous bucket. For example, if 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.
  -lastn N
    Save the last N values of the counter to maintain a &quot;running average&quot; over the last N values.
  -timehist 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 secsPerMinute, which is normally 60, but for testing purposes can be less. Every &quot;hour&quot; (i.e., 60 &quot;minutes&quot;) the contents of the per-minute buckets are summed into the next hourly bucket. Every 24 &quot;hours&quot; 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 secsPerMinute value seen by the package is used for all subsequent time-based histograms.
::counter::count tag ?delta? ?instance?
  Increment the counter identified by tag. The default increment is 1, although you can increment by any value, integer or real, by specifying delta. You must declare each counter with ::counter::init to define the characteristics of counter before you start to use it. If the counter type is -group, then the counter identified by instance is incremented.
::counter::start tag instance
  Record the starting time of an interval. The tag is the name of the counter defined as a -hist value-based histogram. The instance is used to distinguish this interval from any other intervals that might be overlapping this one.
::counter::stop tag instance
  Record the ending time of an interval. The delta time since the corresponding ::counter::start call for instance is recorded in the histogram identified by tag.
::counter::get tag args
  Return statistics about a counter identified by tag. The args determine what value to return:
  -total
    Return the total value of the counter. This is the default if args is not specified.
  -totalVar
    Return the name of the total variable. Useful for specifying with -textvariable in a Tk widget.
  -N
    Return the number of samples accumulated into the counter.
  -avg
    Return the average of samples accumulated into the counter.
  -avgn
    Return the average over the last N samples taken. The N value is set in the ::counter::init call.
  -hist bucket
    If 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.
  -histVar
    Return the name of the histogram array variable.
  -histHour
    Return the complete hourly histogram in array get format sorted by bucket.
  -histHourVar
    Return the name of the hourly histogram array variable.
  -histDay
    Return the complete daily histogram in array get format sorted by bucket.
  -histDayVar
    Return the name of the daily histogram array variable.
  -resetDate
    Return the clock seconds value recorded when the counter was last reset.
  -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.
::counter::exists tag
  Returns 1 if the counter is defined.
::counter::names
  Returns a list of all counters defined.
::counter::histHtmlDisplay tag args
  Generate HTML to display a histogram for a counter. The args control the format of the display. They are:
  -title string
    Label to display above bar chart
  -unit unit
    Specify minutes, hours, or days for the time-base histograms. For value-based histograms, the unit is used in the title.
  -images url
    URL of /images directory.
  -gif filename
    Image for normal histogram bars. The filename is relative to the -images directory.
  -ongif filename
    Image for the active histogram bar. The filename is relative to the -images directory.
  -max N
    Maximum number of value-based buckets to display.
  -height N
    Pixel height of the highest bar.
  -width N
    Pixel width of each bar.
  -skip N
    Buckets to skip when labeling value-based histograms.
  -format string
    Format used to display labels of buckets.
  -text boolean
    If 1, a text version of the histogram is dumped, otherwise a graphical one is generated.