[gentoo-user] Getting BC not to truncate at the decimal point?

[gentoo-user] Getting BC not to truncate at the decimal point?

[Mike Huber]

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Hi,
   I'm just trying to do some quick calculations using bc, but the version
installed through portage truncates on multiplication/division.  It didn't
used to do this 2 years ago when I was taking number theory, and there are
no USE flags available for sys-devel/bc to change this.  From the manpage:

---------------------------------------------------------------------

The most basic element in bc is the number.  Numbers are arbitrary precision
numbers.  This precision is both in the  integer  part  and  the fractional
part.  All numbers are represented internally in decimal and all computation
is done in decimal.  (This  version  truncates  results from divide and
multiply operations.)  There are two attributes of numbers, the length and
the scale.  The length is the total number of significant  decimal  digits
in a number and the scale is the total number of decimal digits after the
decimal point.  For example:
               .000001 has a length of 6 and scale of 6.
               1935.000 has a length of 7 and a scale of 3.


------------------------------------------------------------------------


Anyone have any ideas?

--Mike

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Re: [gentoo-user] Getting BC not to truncate at the decimal point?

[brettholcomb]

Did you try

scale=n

Where n is the number of digits after the decimal?  More in man bc.

> 
> From: "Mike Huber" <michael.huber@gmail.com>
> Date: 2006/05/24 Wed PM 12:48:29 EDT
> To: gentoo-user@lists.gentoo.org
> Subject: [gentoo-user] Getting BC not to truncate at the decimal point?
> 
> Hi,
>    I'm just trying to do some quick calculations using bc, but the version
> installed through portage truncates on multiplication/division.  It didn't
> used to do this 2 years ago when I was taking number theory, and there are
> no USE flags available for sys-devel/bc to change this.  From the manpage:
> 
> ---------------------------------------------------------------------
> 
> The most basic element in bc is the number.  Numbers are arbitrary precision
> numbers.  This precision is both in the  integer  part  and  the fractional
> part.  All numbers are represented internally in decimal and all computation
> is done in decimal.  (This  version  truncates  results from divide and
> multiply operations.)  There are two attributes of numbers, the length and
> the scale.  The length is the total number of significant  decimal  digits
> in a number and the scale is the total number of decimal digits after the
> decimal point.  For example:
>                .000001 has a length of 6 and scale of 6.
>                1935.000 has a length of 7 and a scale of 3.
> 
> 
> ------------------------------------------------------------------------
> 
> 
> Anyone have any ideas?
> 
> --Mike
> 
> 

-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Getting BC not to truncate at the decimal point?

[Mike Huber]

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duh, sorry, case of me not fully reading the manpage.  I'll be sure and
fully read before I send to the list.

Thanks a lot,
--Mike

On 5/24/06, brettholcomb@bellsouth.net <brettholcomb@bellsouth.net> wrote:
>
> Did you try
>
> scale=n
>
> Where n is the number of digits after the decimal?  More in man bc.
>
> >
> > From: "Mike Huber" <michael.huber@gmail.com>
> > Date: 2006/05/24 Wed PM 12:48:29 EDT
> > To: gentoo-user@lists.gentoo.org
> > Subject: [gentoo-user] Getting BC not to truncate at the decimal point?
> >
> > Hi,
> >    I'm just trying to do some quick calculations using bc, but the
> version
> > installed through portage truncates on multiplication/division.  It
> didn't
> > used to do this 2 years ago when I was taking number theory, and there
> are
> > no USE flags available for sys-devel/bc to change this.  From the
> manpage:
> >
> > ---------------------------------------------------------------------
> >
> > The most basic element in bc is the number.  Numbers are arbitrary
> precision
> > numbers.  This precision is both in the  integer  part  and  the
> fractional
> > part.  All numbers are represented internally in decimal and all
> computation
> > is done in decimal.  (This  version  truncates  results from divide and
> > multiply operations.)  There are two attributes of numbers, the length
> and
> > the scale.  The length is the total number of
> significant  decimal  digits
> > in a number and the scale is the total number of decimal digits after
> the
> > decimal point.  For example:
> >                .000001 has a length of 6 and scale of 6.
> >                1935.000 has a length of 7 and a scale of 3.
> >
> >
> > ------------------------------------------------------------------------
> >
> >
> > Anyone have any ideas?
> >
> > --Mike
> >
> >
>
> --
> gentoo-user@gentoo.org mailing list
>
>

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Re: [gentoo-user] Getting BC not to truncate at the decimal point?

[Brett I. Holcomb]

You're welcome.  Don't feel bad - it took me a "This thing can't be that dumb" 
and a man page read to find out it was smarter than I thought <G>.

On Wednesday May 24 2006 17:15, Mike Huber wrote:
> duh, sorry, case of me not fully reading the manpage.  I'll be sure and
> fully read before I send to the list.
>
> Thanks a lot,
> --Mike
>
> On 5/24/06, brettholcomb@bellsouth.net <brettholcomb@bellsouth.net> wrote:
> > Did you try
> >
> > scale=n
> >
> > Where n is the number of digits after the decimal?  More in man bc.
> >
> > > From: "Mike Huber" <michael.huber@gmail.com>
> > > Date: 2006/05/24 Wed PM 12:48:29 EDT
> > > To: gentoo-user@lists.gentoo.org
> > > Subject: [gentoo-user] Getting BC not to truncate at the decimal point?
> > >
> > > Hi,
> > >    I'm just trying to do some quick calculations using bc, but the
> >
> > version
> >
> > > installed through portage truncates on multiplication/division.  It
> >
> > didn't
> >
> > > used to do this 2 years ago when I was taking number theory, and there
> >
> > are
> >
> > > no USE flags available for sys-devel/bc to change this.  From the
> >
> > manpage:
> > > ---------------------------------------------------------------------
> > >
> > > The most basic element in bc is the number.  Numbers are arbitrary
> >
> > precision
> >
> > > numbers.  This precision is both in the  integer  part  and  the
> >
> > fractional
> >
> > > part.  All numbers are represented internally in decimal and all
> >
> > computation
> >
> > > is done in decimal.  (This  version  truncates  results from divide and
> > > multiply operations.)  There are two attributes of numbers, the length
> >
> > and
> >
> > > the scale.  The length is the total number of
> >
> > significant  decimal  digits
> >
> > > in a number and the scale is the total number of decimal digits after
> >
> > the
> >
> > > decimal point.  For example:
> > >                .000001 has a length of 6 and scale of 6.
> > >                1935.000 has a length of 7 and a scale of 3.
> > >
> > >
> > > -----------------------------------------------------------------------
> > >-
> > >
> > >
> > > Anyone have any ideas?
> > >
> > > --Mike
> >
> > --
> > gentoo-user@gentoo.org mailing list

-- 

Brett I. Holcomb
-- 
gentoo-user@gentoo.org mailing list

Re: [gentoo-user] Getting BC not to truncate at the decimal point?

[John Green]

Mike Huber wrote:

> Hi,
>    I'm just trying to do some quick calculations using bc, but the
> version installed through portage truncates on
> multiplication/division.  It didn't used to do this 2 years ago when I
> was taking number theory, and there are no USE flags available for
> sys-devel/bc to change this.  From the manpage:
>
> ---------------------------------------------------------------------
>
> The most basic element in bc is the number.  Numbers are arbitrary
> precision numbers.  This precision is both in
> the  integer  part  and  the fractional part.  All numbers are
> represented internally in decimal and all computation is done in
> decimal.  ( This  version  truncates  results from divide and multiply
> operations.)  There are two attributes of numbers, the length and the
> scale.  The length is the total number of significant  decimal  digits
> in a number and the scale is the total number of decimal digits after
> the decimal point.  For example:
>                .000001 has a length of 6 and scale of 6.
>                1935.000 has a length of 7 and a scale of 3.
>
>
> ------------------------------------------------------------------------
>
>
> Anyone have any ideas?
>
> --Mike

Hi,

Try this.

$ echo '1/5' | bc
0
$ echo '1/5' | bc -l
.20000000000000000000

I don't think bc has changed in a long time.
Maybe you forgot the -l option.

You can also control the scale explicitly like this.

echo 'scale=3;1/5' | bc -l
.200

Hope this helps.

John Green




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