* Incorrect sum of times in table
@ 2013-07-01 17:38 Paul Stansell
2013-07-01 20:49 ` Nick Dokos
0 siblings, 1 reply; 4+ messages in thread
From: Paul Stansell @ 2013-07-01 17:38 UTC (permalink / raw)
To: emacs-orgmode
Hello,
I noticed a case where the sum of two times in a table does not give
the correct answer.
To see this, create an org file with the following lines:
| 0:00:31 |
| 0:00:30 |
|---------|
| |
Open it and type C-+ C-y in the empty cell of the table. The answer
inserted is 0:01:00 instead of 0:01:01.
Regards,
Paul
PS. I'm using Emacs 24.2.1 and Org-mode release_8.0.3-331-gf7e6f1 and
I tested with the minimal org-mode set-up from
http://orgmode.org/manual/Feedback.html.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Incorrect sum of times in table
2013-07-01 17:38 Incorrect sum of times in table Paul Stansell
@ 2013-07-01 20:49 ` Nick Dokos
2013-07-01 21:22 ` Bastien
0 siblings, 1 reply; 4+ messages in thread
From: Nick Dokos @ 2013-07-01 20:49 UTC (permalink / raw)
To: emacs-orgmode
Paul Stansell <paulstansell@gmail.com> writes:
> Hello,
>
> I noticed a case where the sum of two times in a table does not give
> the correct answer.
>
> To see this, create an org file with the following lines:
>
> | 0:00:31 |
> | 0:00:30 |
> |---------|
> | |
>
> Open it and type C-+ C-y in the empty cell of the table. The answer
> inserted is 0:01:00 instead of 0:01:01.
>
I think you mean C-c +.
The problem is that these things are calculated as decimal hours, using
floating point arithmetic and you get truncation towards 0 when the
value is printed out as an integer. The format in org-table-sum is
(format "%d:%02d:%02d" h m s)
but s is 0.9999... and it gets formatted as 0.
It might be better to use
(format "%.0f:%02.0f:%02.0f" h m s)
i.e. as floating point with no places after the decimal point
(in which case the decimal point does not seem to be output).
But there may be other problems that I have not thought of.
It might be even better to round the floating point number to
the nearest integer and use %d formats instead:
(format "%d:%02d:%02d" (round h) (round m) (round s))
--
Nick
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: Incorrect sum of times in table
2013-07-01 20:49 ` Nick Dokos
@ 2013-07-01 21:22 ` Bastien
2013-07-03 8:18 ` Bastien
0 siblings, 1 reply; 4+ messages in thread
From: Bastien @ 2013-07-01 21:22 UTC (permalink / raw)
To: Nick Dokos; +Cc: emacs-orgmode
Hi Nick,
Nick Dokos <ndokos@gmail.com> writes:
> I think you mean C-c +.
>
> The problem is that these things are calculated as decimal hours, using
> floating point arithmetic and you get truncation towards 0 when the
> value is printed out as an integer. The format in org-table-sum is
>
> (format "%d:%02d:%02d" h m s)
>
> but s is 0.9999... and it gets formatted as 0.
>
> It might be better to use
>
> (format "%.0f:%02.0f:%02.0f" h m s)
>
> i.e. as floating point with no places after the decimal point
> (in which case the decimal point does not seem to be output).
> But there may be other problems that I have not thought of.
> It might be even better to round the floating point number to
> the nearest integer and use %d formats instead:
>
> (format "%d:%02d:%02d" (round h) (round m) (round s))
Both solutions work -- we don't need to fear other problems here,
`org-table-sum' is pretty isolated, so I'd say "please go ahead!
and fix this in maint.
Thanks,
--
Bastien
^ permalink raw reply [flat|nested] 4+ messages in thread
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2013-07-01 17:38 Incorrect sum of times in table Paul Stansell
2013-07-01 20:49 ` Nick Dokos
2013-07-01 21:22 ` Bastien
2013-07-03 8:18 ` Bastien
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