Z-test

#!/usr/bin/env bash

# Thu 11 May 2023 06:06:33 PM CEST - mayer



# https://www.cliffsnotes.com/study-guides/statistics/univariate-inferential-tests/two-sample-z-test-for-comparing-two-means
# http://homework.uoregon.edu/pub/class/es202/ztest.html


if test $# -ne 6
  then
    echo usage: $0 mean1 deviation1 size1 mean2 deviation2 size2
    exit 1
fi

# convert for example 1.14776e-06 to 0.00000114776000000000 for DC
M1=`echo $1 | awk '{ printf ( "%0.20f\n" , $1 ) }'`
D1=`echo $2 | awk '{ printf ( "%0.20f\n" , $1 ) }'`
S1=`echo $3 | awk '{ printf ( "%0.20f\n" , $1 ) }'`
M2=`echo $4 | awk '{ printf ( "%0.20f\n" , $1 ) }'`
D2=`echo $5 | awk '{ printf ( "%0.20f\n" , $1 ) }'`
S2=`echo $6 | awk '{ printf ( "%0.20f\n" , $1 ) }'`


dc <<< "15k $M1 $M2 - $D1 $D1  * $S1 / $D2 $D2 * $S2 / + v / p" | \
	awk '{ printf ( "%.2g\n" , $1 ) }'


dc <<< "15k $M1 $M2 - $D1 $D1  * $S1 / $D2 $D2 * $S2 / + v / p" | \
awk '{ printf ( "%.2g\n" , $1 < 0 ? -$1 : $1  ) }' | \
awk '{ if ( $1 < 2.0 ) print ( "probes are the same " )
else
  {
    if ( $1 < 2.5 ) print ( "probes are marginally different " )
      else
        {
          if ( $1 < 3.0 ) print ( "probes are significant different " )
            else
              {
                 print ( "probes highly significant different " )
              }
        }
  }
}'  

# ztest_ksh 287.126750000000 0.202184 4  287.320500000000 0.202184 6
1.5
probes are the same