[Date Index]
[Thread Index]
[Author Index]
Re: Chained-functional notation examples?
*To*: mathgroup at smc.vnet.net
*Subject*: [mg132705] Re: Chained-functional notation examples?
*From*: "Hans Michel" <hmichel at cox.net>
*Date*: Fri, 9 May 2014 02:06:47 -0400 (EDT)
*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com
*Delivered-to*: l-mathgroup@wolfram.com
*Delivered-to*: mathgroup-outx@smc.vnet.net
*Delivered-to*: mathgroup-newsendx@smc.vnet.net
*References*: <zLEb1n00r1r5Uyi01LEcLm> <000901cf6ac8$b3fb5470$1bf1fd50$@cox.net> <zScg1n0170owH2401SchCY>
I think the dates would have to be rounded to Day then the AbsoluteTime
would be more comparable.
AbsoluteTime[DayRound[DateList[], All]] <
AbsoluteTime[DayRound[DayPlus[DateList[], 3], All]]
Issues may be file dates compared to current date time, rounding and
location (timezone) issues.
DayRound is New in version 9
Switch to Take[] goes all the back to v1. AbsoluteTime v2.
AbsoluteTime[Take[DateList[], 3]] <
AbsoluteTime[Take[DayPlus[DateList[], 3], 3]]
FileDate[] in the original suggestion by Daniel only goes back to v3.
To address the poster's original questions: I don't believe that
Mathematica has issues in filtering or using a water-fall like method. I
can't speak to if Mathematica optimizes such a process.
Hans
-----Original Message-----
From: Daniel Lichtblau [mailto:danl at wolfram.com]
Sent: Thursday, May 08, 2014 9:37 AM
To: Hans Michel; mathgroup at smc.vnet.net
Subject: [mg132705] Re: Chained-functional notation examples?
On 05/08/2014 09:20 AM, Hans Michel wrote:
> Daniel:
>
> Now What's the catch with Today?
>
> Today will only work in Wolfram Language (Mathematica v 10), which may
> be officially released Tomorrow?
>
> One can go on with a Who's on First theme. (Goes along with W|A
> baseball
> data)
>
> But currently the DateObject "Today" would have to be changed to
> something that would work in Mathematica 9 or below.
>
> Hans
Hans et al,
You are correct, I was using an unreleased version. Actually some good came
of it (I found a weakness in date comparisons that got addressed).
I'll leave modification for versions <=9 to others more adept at this sort
of thing. I never was much good with dates...
As for baseball,
http://www.redreporter.com/2012/2/13/2796324/hus-on-first-a-modernization
Daniel
> -----Original Message-----
> From: Daniel Lichtblau [mailto:danl at wolfram.com]
> Sent: Thursday, May 08, 2014 3:08 AM
> To: mathgroup at smc.vnet.net
> Subject: Re: Chained-functional notation examples?
>
>
> A query such as this might do what you have in mind. Here
> directoryname should be changed to whatever directory you want searched.
>
> Select[FileNames[("*uid*" | "*UID*"), directoryname, Infinity],
> ((StringMatchQ[DirectoryName[#] , "*egal*"] && Today <
> DayPlus[FileDate[#], 3]) &]
>
> Also there is a case sensitive switch if you want to allow strings with
e.g.
> "uID". If you want to allow that uid only in the name and not full
> string
>
> Daniel Lichtblau
> Wolfram Research
>
> -------------------
>
> On Tue, 06 May 2014 06:26:46 +0000, Unknown wrote:
>
> > I came to 'Mathematica' via Xahlee's criticism of the ad-hoc
> nature of > unix-piping [functional notation]. He claims [& I
> believe him] that > Mathematica has a better, more consistent
> notation. But the facility of > PRE, IN & POST-fix alternatives,
> seems bad. You want ONE way of > acieving the goal. More rules just
increases mental load.
> >
> > A major benefit of functional [unix-piping] programming style, is
> that > you don't need to remember the-full-journey: you just need to
> remember > the previous stage's output. Nor do you need to remember
several names:
> > the previous output is just "it". A superficial read through a
> recent > article[s] here, about <collecting data from several
> servers, and > agregating it, and sending the result to a master>
> seemed very > interesting, and matches my ideas of using functional
> programming. But > I can't afford to invest in ANOTHER
> notation/syntax, without good > prospect of productivety increase.
> >
> > Just as a test, how would Mathematica handle the following [or
> part of]
>> little task:
> >
> > search all files in Dir=tree D |
> > which are less than N days-old |
> > and which contain string S1 |
> > and which contain string S2 .
> >
> > Actually, this seems not a good example, since it's biased towards
> the > *nix file system's format/syntax.
> >
> > Try:
> > Search in table of ListOfOpenFiles for lineS with path-P [field] |
> > which have same tty-field as line with path-P2 & program-M [field]
> > > This sounds like a data-base problem?
> >
> > Or is there a nice list of 'such' Mathematica examples?
> >
> > Thanks,
> >
> > == John Grant.
>
> Here's a related real-live problem:
> list all files in Dir-tree:D |
> which are less-than daysOld:N |
> and contain "egal" in the FullPathName |
> and contain String:"uid" OR "UID"
>
Prev by Date:
**Re: Chained-functional notation examples?**
Next by Date:
**Numerical solution from Module**
Previous by thread:
**Re: Chained-functional notation examples?**
Next by thread:
**Re: Chained-functional notation examples?**
| |