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Aaron_Davies

Subject: compression stats uploadedDate: Mon, 14 Oct 2013 13:52:24 -0400Message-Id: <9193B9A8-D9C1-4E39-82D5-94BF1B8558FD@gmail.com>To: k4@listbox.com, personal-kdbplus@googlegroups.comMime-Version: 1.0 (Apple Message framework v1283)X-Mailer: Apple ...

Aaron_Davies

Subject: riddlesDate: Sun, 4 Nov 2012 18:38:10 -0500Message-Id: <8137812C-00BD-4AD5-B571-3CA249C62CF7@gmail.com>To: personal-kdbplus@googlegroups.comMime-Version: 1.0 (Apple Message framework v1278)X-Mailer: Apple Mail (2.1278)i've posted a q riddle ...

Aaron_Davies

shouldn't matter either, there's an overload of -1! that translatesthatq)-1!"\t1}"" 1}"you can see it being called by the script loader if you fiddle aroundin a debug shell caused by a bad code file$ echo ']'>bar.q$ q bar.qKDB+ 2.6 2010.12.17 Copyrig...

Aaron_Davies

life in one line of APL, recently popular on reddit, etc.http://www.youtube.com/watch?v=a9xAKttWgP4&fmt=18my q portfps:"I"$first((.Q.opt .z.x)`fps),"5".q.clear:{1"\033[H\033[J";}disp:{1@-1_` sv .Q.s each x;}life:{any(1b;x)&'3 4=\:sum sum f(f:rotate'\...

Aaron_Davies

Content-Disposition: inlinehttp://www.amazon.com/gp/product/1593271905can we get jeff to partner w/this guy?-- Aaron Daviesaaron.davies@gmail.com

Aaron_Davies

backtick marks literal symbols — it's a type signifier, like thetrailing letters used for the other types (0b "0 as a boolean", 7h "7as a short (integer), 1f "one as a (64-bit) float", etc.)it's like leading unpaired apostrophe from lisp, if that hel...

Aaron_Davies

there isn't much documentation for k4 availableif you have help.q loaded, help`verb is a good place to start — itgives you the monadic meanings of the punctuation functions (! is key,@ is type, etc.)you can also search .q for the functions that are d...

Aaron_Davies

there's a builtin string rounder that's used by .Q.fmtq)3 .Q.f'12.12345 12.12355"12.123""12.124"q)you can use "get" (or "F"$, etc.) on the result if you want it back asa number, not a stringthere's also xbar, but that effectively uses floor, not roun...

Aaron_Davies

basically, re-enumerate one by the other's symfile, then you canmanipulate the data as you likeshould be something like\l hdb2\l dbmaint.q{fncol'[`:.;x;exec c from meta x wheret="s";`:/path/to/hdb1/sym?get@]}each{x where -1h=(type .Q.qp get@)eachx}ta...

Aaron_Davies

note that this solution is the only one that works on partitioned tablescan be shortened and generalized to work with multi-column group as{?[x;();y!y,:();c!first,/:c:(cols x)except y]}(just to throw another one out there, there's also {first each'xx...

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riddles

Re: different result when you run q by putting #! head or q command

life in one line of q

new meaning to "illustrated guide"

Re: underlying reason of back tick

Re: how do I read this k function

Re: round digits

Re: merge hdb

Re: Get first row from a group