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Issue with years-from-duration!?

Friday, 6 December 2019 · 6 messages
FB
France Baril6 Dec 2019 11:23 #

Hi,

The following function returns P4511D: 0 but I expect P4511D: 12 Bug or bad usage?

let $d1 := xs:date('2007-07-31')
Quoted text · 4 lines
> let $d2 := xs:date('2019-12-06') > let $duration := $d2 - $d1 > let $years := years-from-duration($duration) > return $duration || ': ' || $years
-- France Baril Architecte documentaire / Documentation architect france.baril at architextus.com
MH
Martin Honnen6 Dec 2019 11:32 #
Quoted text · France Baril · 13 lines
Am 06.12.2019 um 11:23 schrieb France Baril: > > > The following function returns P4511D: 0 but I expect P4511D: 12 > Bug or bad usage? > > let $d1 := xs:date('2007-07-31') > let $d2 := xs:date('2019-12-06') > let $duration := $d2 - $d1 > let $years := years-from-duration($duration) > return $duration || ': ' || $years > >

The spec https://www.w3.org/TR/xpath-functions/#func-years-from-duration says "If|$arg|is an|xs:dayTimeDuration|the function returns 0.".

MH
Martin Honnen6 Dec 2019 11:38 #
Quoted text · Martin Honnen · 20 lines
Am 06.12.2019 um 11:32 schrieb Martin Honnen: > Am 06.12.2019 um 11:23 schrieb France Baril: >> >> >> The following function returns P4511D: 0 but I expect P4511D: 12 >> Bug or bad usage? >> >> let $d1 := xs:date('2007-07-31') >> let $d2 := xs:date('2019-12-06') >> let $duration := $d2 - $d1 >> let $years := years-from-duration($duration) >> return $duration || ': ' || $years >> >> > > The spec > https://www.w3.org/TR/xpath-functions/#func-years-from-duration says > "If|$arg|is an|xs:dayTimeDuration|the function returns 0.". > >

As a workaround, see https://www.oxygenxml.com/archives/xsl-list/200601/msg00446.html which tries to compute the years from the dayTimeDuration.

CG
Christian Grünin reply to France Baril, 6 Dec 2019, 11:236 Dec 2019 11:38 #

Hi France,

The function fn:years-from-duration is fairly basic; it only returns the year component of your duration argument (as xs:dayTimeDuration has none, in contrast to xs:yearMonthDuration). The background: A year may have 365 or 366 days, and the duration is not sufficient to compute the number of years.

You can use the average number of years for your computation if that’s sufficient for your use case (see [1] for a variety of approximations to choose from):

  let $d1 := xs:date('2007-07-31')
  let $d2 := xs:date('2019-12-06')
  let $duration := $d2 - $d1
  let $days := days-from-duration($duration)
  return $days div 365.2425

Best, Christian

[1] https://en.wikipedia.org/wiki/Year

Quoted text · France Baril · 13 lines
On Fri, Dec 6, 2019 at 11:24 AM France Baril <france.baril at architextus.com> wrote: > > Hi, > > The following function returns P4511D: 0 but I expect P4511D: 12 > Bug or bad usage? > >> let $d1 := xs:date('2007-07-31') >> let $d2 := xs:date('2019-12-06') >> let $duration := $d2 - $d1 >> let $years := years-from-duration($duration) >> return $duration || ': ' || $years
FB
France Baril6 Dec 2019 11:52 #

I was going to ask if I could count on the difference always being in a PxxxD format. I am happy to see that days-from-duration doesn't return 0. I tried casting the xs:duration to many formats and kept getting 0.

Thanks for the tips

Quoted text · Christian Grün · 41 lines
On Fri, Dec 6, 2019 at 11:38 AM Christian Grün <christian.gruen at gmail.com> wrote: > Hi France, > > The function fn:years-from-duration is fairly basic; it only returns > the year component of your duration argument (as xs:dayTimeDuration > has none, in contrast to xs:yearMonthDuration). The background: A year > may have 365 or 366 days, and the duration is not sufficient to > compute the number of years. > > You can use the average number of years for your computation if that’s > sufficient for your use case (see [1] for a variety of approximations > to choose from): > > let $d1 := xs:date('2007-07-31') > let $d2 := xs:date('2019-12-06') > let $duration := $d2 - $d1 > let $days := days-from-duration($duration) > return $days div 365.2425 > > Best, > Christian > > [1] https://en.wikipedia.org/wiki/Year > > > > On Fri, Dec 6, 2019 at 11:24 AM France Baril > <france.baril at architextus.com> wrote: > > > > Hi, > > > > The following function returns P4511D: 0 but I expect P4511D: 12 > > Bug or bad usage? > > > >> let $d1 := xs:date('2007-07-31') > >> let $d2 := xs:date('2019-12-06') > >> let $duration := $d2 - $d1 > >> let $years := years-from-duration($duration) > >> return $duration || ': ' || $years >
-- France Baril Architecte documentaire / Documentation architect france.baril at architextus.com
CG
Christian Grün6 Dec 2019 11:59 #

For advanced computations, it’s sometimes easier to convert duration items to milliseconds with our custom functions [1]:

  let $ms-years := 1000 * 60 * 60 * 24 * 365
  let $dur := xs:dayTimeDuration('P12345DT2M3S')
  let $ms := convert:dayTime-to-integer($dur)
  return $ms idiv $ms-years

[1] http://docs.basex.org/wiki/Conversion_Module#convert:dayTime-to-integer

Quoted text · France Baril · 54 lines
On Fri, Dec 6, 2019 at 11:52 AM France Baril <france.baril at architextus.com> wrote: > > I was going to ask if I could count on the difference always being in a PxxxD format. I am happy to see that days-from-duration doesn't return 0. I tried casting the xs:duration to many formats and kept getting 0. > > Thanks for the tips > > On Fri, Dec 6, 2019 at 11:38 AM Christian Grün <christian.gruen at gmail.com> wrote: >> >> Hi France, >> >> The function fn:years-from-duration is fairly basic; it only returns >> the year component of your duration argument (as xs:dayTimeDuration >> has none, in contrast to xs:yearMonthDuration). The background: A year >> may have 365 or 366 days, and the duration is not sufficient to >> compute the number of years. >> >> You can use the average number of years for your computation if that’s >> sufficient for your use case (see [1] for a variety of approximations >> to choose from): >> >> let $d1 := xs:date('2007-07-31') >> let $d2 := xs:date('2019-12-06') >> let $duration := $d2 - $d1 >> let $days := days-from-duration($duration) >> return $days div 365.2425 >> >> Best, >> Christian >> >> [1] https://en.wikipedia.org/wiki/Year >> >> >> >> On Fri, Dec 6, 2019 at 11:24 AM France Baril >> <france.baril at architextus.com> wrote: >> > >> > Hi, >> > >> > The following function returns P4511D: 0 but I expect P4511D: 12 >> > Bug or bad usage? >> > >> >> let $d1 := xs:date('2007-07-31') >> >> let $d2 := xs:date('2019-12-06') >> >> let $duration := $d2 - $d1 >> >> let $years := years-from-duration($duration) >> >> return $duration || ': ' || $years > > > > -- > France Baril > Architecte documentaire / Documentation architect > france.baril at architextus.com

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