Subversion Repositories wimsdev

!if $wims_read_parm!=slib_header
  !goto proc
!endif
slib_author=Bernadette, Perrin-Riou

slib_title=Repeating decimal of a rational
slib_parms=2\
,rational number as a fraction of integer numbers\
raw,format
slib_out=return [length of the non-periodic decimal part, length of the periodic pattern],\
  [integral part , non-periodic part, periodic pattern] in default format.\
  If the option is <span class="tt">tex</span> the second item is the formatted number\
  with overlined periodic pattern.
!set slib_comment=do not check if the rational number is written as a \
  fraction of integer numbers.
!set slib_example=34/45,tex\
34/45\
297/670\
453/37,tex\
453/37\
65/12,tex\
65/12\
67/66,tex\
67/66

!exit

:proc

!!borner le dénominateur
!reset slib_format slib_out
!distribute item $wims_read_parm into slib_n,slib_format
!default slib_format=raw
slib_res=!exec pari algo(x)={my(b,r,s);b=denominator(x);r=valuation(b,2);s=valuation(b,5);\
  [max(r,s),znorder(Mod(10,b/2^r/5^s)),x*1.]};\
  algo($slib_n)
slib_res=!nospace $slib_res
slib_rn=$(slib_res[3])
slib_rn=!replace internal . by , in $slib_rn
slib_test=!charcnt $(slib_rn[2])
!if $(slib_res[2]) > $slib_test-1
  slib_out=!nospace [$(slib_res[1,2])]
  !exit
!endif
slib_per=!char $(slib_res[1])+1 to $(slib_res[1])+$(slib_res[2]) of $(slib_rn[2])
!reset slib_beg
!if $(slib_res[1])>0
  slib_beg=!char 1 to $(slib_res[1]) of $(slib_rn[2])
!endif
!if $slib_format=tex
  slib_out=[$(slib_res[1,2])],\($(slib_rn[1]).$slib_beg\overline{$slib_per}\)
!else
  slib_out=[$(slib_res[1,2])],[$(slib_rn[1]),$slib_beg,$slib_per]
!endif