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]
slib_require=pari
!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