Subversion Repositories wimsdev

!if $wims_read_parm!=slib_header

!goto proc

!endif

slib_title=Variance

slib_parms=1\

 ,[data] or [data],[weight]

slib_author=Bernadette PERRIN-RIOU

slib_out=standard variance of data x_1,..,x_n = sum(x_i^2-mean)/n, sum(x_i^2-mean)/(n-1)

slib_comment=Data and weight can be recognized under many formats, \

 in particular as a matrix (with data before weight).

slib_example=[2,-7,6]\

[2,-7,6;1,1,4]\

[2,-7,6],[1,1,4]

!exit

:proc

!readproc slib/stat/dataproc $wims_read_parm

slib_cnt=!itemcnt $slib_data

!if $slib_cnt=0

slib_out=0

!else

!if $slib_weight=$empty

  slib_data1=!sum x for x in $slib_data

  slib_mean=$[($slib_data1)/$slib_cnt]

  slib_dev=!sum (x-($slib_mean))^2 for x in $slib_data

  slib_out=$[$slib_dev/$slib_cnt],$[$slib_dev/($slib_cnt-1)]

  slib_out =!trim $slib_out

  !exit

 !else

  slib_out=!exec pari { slib_mean=([$slib_data]*[$slib_weight]~)/$slib_tw;\

slib_dev=sum(x=1,$slib_cnt,[$slib_weight][x]*[$slib_data][x]^2)-$slib_tw*(slib_mean)^2;\

  print(1.*slib_dev/$slib_tw","1.*slib_dev/($slib_tw-1))}

  slib_out =!trim $slib_out

 !endif weight

  slib_out =!trim $slib_out

!endif

slib_out=!trim $slib_out