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# Statistics Usage

This is a little demonstration of how to use statistics with TCL. Here, I provide two methods: 1. Trivially, some PROCS that perform statistic calulations. However, you are *NOT* supposed to use these, but use rather build-in statistics from 2. math::statistics (provided by tcllib that must be installed).

#!/usr/bin/tclsh # statistics-usage.tcl # # 2005 by Sascha Tayefeh # # This is a little demonstration of how to use statistics # with TCL. Here, I provide two methods: 1. Trivially, some # PROCS that perform statistic calulations. However, you # are *NOT* supposed to use these, but use rather build-in # statistics from 2. math::statistics (provided by tcllib # that must be installed). # # for further information read # http://aspn.activestate.com/ASPN/docs/ActiveTcl/tcllib/math/statistics.html # # package require Tcl 8.4 package require math::statistics proc sas_sum { valist } { set summe 0.0 foreach val $valist { set summe [ expr $summe + $val ] } return $summe } proc sas_mean { valist } { set n [ llength $valist ] set sum [ sas_sum $valist ] set mean [ expr $sum / $n ] return $mean } proc sas_variance { valist } { set variance 0.0 set mean [ sas_mean $valist ] set n [ llength $valist ] foreach val $valist { set buff [ expr $val - $mean ] set buff [ expr pow ($buff,2)] set variance [ expr $variance + $buff ] } set variance [ expr $variance / $n ] return $variance } proc sas_deviation { valist } { set variance [ sas_variance $valist ] set deviation [ expr sqrt ($variance) ] return $deviation } #set data1 [ list 5 2.4 5.3 2.3 4.3 2.3 3.3 4.4 5.4 3.4 5.4 2.3 1.2 3.4] #set data2 [ list 1.9 -2.4 -5.3 2.3 4.3 2.3 2.3 4.4 5.4 3.4 4.4 2.3 1.2 3.4] # fills data1 with normal-distributed values: <mean> <stdev> <n> set data1 [::math::statistics::random-normal 2.4 2 10] set data2 [::math::statistics::random-normal 5.4 2 10] set mean [ sas_mean $data1 ] set variance [ sas_variance $data1 ] set deviation [ sas_deviation $data1 ] puts "\nFrom Custom Procs:" puts "Mean: $mean, Variance: $variance, stDev: $deviation" puts "\nFrom ::math::statistics:: (needs tcllib)" set mean [ ::math::statistics::mean $data1 ] set variance [ ::math::statistics::var $data1 ] set deviation [ ::math::statistics::stdev $data1 ] set corr [::math::statistics::corr $data1 $data2 ] set crosscorr [::math::statistics::crosscorr $data1 $data2 ] set autocorr [::math::statistics::autocorr $data1 ] #set confi [::math::statistics::interval-mean-stdev $data1 0.95] puts "Mean: $mean, Variance: $variance, stDev: $deviation" puts "Corr: $corr" puts "Autocorr: $autocorr\nCrosscorr: $crosscorr"