Sunday, July 31, 2016
Thursday, July 14, 2016
- June 13th, 2016:
You want this list:
[1, -1, 1, -1, ...]
How would you produce this value in #Haskell ?
- Wai Lee Chin Feman @wchinfeman
(set plop to be identity, and set transformstate to be (*) -1)
- Philipp Maier @AkiiZedd `
iterate negate 1’
- Patrick Mylund @pmylund
concat $ repeat [1, (-1)]
- Gary Fixler @gfixler No need for the parens in a list.
- Jeff Foster @fffej and Kevin Meredith @Gentmen
iterate (* (- 1)) 1
- Spencer Janssen @spencerjanssen and Андреев Кирилл @nonaem00
cycle [1, -1]
- Philipp Maier @AkiiZedd:
I’m curious: Since concat is O(n) wouldn’t it take more and more time depending on how many items you take?
- Patrick Mylund @pmylund Looks like they compile to the same thing https://gist.github.com/patrickmn/9a92ab2a088018b2c0631f3bcfd60ebe
- Philipp Maier @AkiiZedd I’m actually surprised the compiler can optimise this away :o Thanks for showing me
- Eyal Lotem @EyalL
foldr (++), not
foldl. O(1) work is done to produce the next item.
- Philipp Maier @AkiiZedd:
- Wai Lee Chin Feman @wchinfeman
- David Turner @DaveCTurner I'd actually write '
cycle [1,-1]' but I like the elegant, alliterative obscurity of '
iterate negate 1'
- Fatih Karakurt @karakfa
Friday, July 1, 2016
- June 29th, 2016: Today's #Haskell exercise is REALLY HARD! ... for Big Gov't. Can you solve it? A little bit of (well-typed) Prolog-like code gets us our #haskell solution for today
- June 28th, 2016: For today's #haskell problem we do ... NOTHING! But we are introduced to coding software for a huge bureaucracy ... AAAAANNNDDD three System imports and we've got today's #haskell solution. Groovy!
- June 24th, 2016: #haskell problem today charts Stochastic Oscillators of a security and includes a 'malus' problem: report generation
- June 23rd, 2016: Today we look at using #haskell to chart moving averages of a stock's prices https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D23/Exercise.hs https://twitter.com/logicalgraphs/status/743409829843243008
- June 21th, 2016: I pushed today's #haskell problem last night on git but did I announce it? sigh Complex roots of quadratic equations https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D21/Exercise.hs The #haskell solution gives us the Complex roots to any (Real) quadratic equation https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D21/Solution.hs
- June 20th, 2016: Solving quadratic equations is on the plate for today's #haskell exercise https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D20/Exercise.hs It's not every day I codeThank you, #haskell, for today's solution to do sohttps://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D20/Solution.hs
- June 17th, 2016: My, my! Where has the day flown? Today's #haskell problem is to reinvent charting API! ... or not. https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D17/Exercise.hs
- June 16th, 2016: Today's #haskell exercise looks at representing $TWTR data as candlesticks https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D16/Exercise.hs
- June 15th, 2016: For today's #haskell problem, we round out the Data.Matrix module with the definition of the identity matrix https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D15/Exercise.hs There are many ways to define the identity matrix. Today's #haskell solution does so with Cellular Automata Rule 16 https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D15/Solution.hs
- June 14th, 2016: Yesterday we computed the matrix determinant, today we'll invert a matrix and use it to solve systems of equations https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D14/Exercise.hs Today's #haskell solution inverts a matrix BECAUSE WE FEEL LIKE IT! Yeah https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D14/Solution.hs
- June 13th, 2016: For today's #haskell problem we *ahem* DETERMINE (eventually) to solve systems of equations https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D13/Exercise.hs The determinant is the sum of the products of the first row with the sub-matrix determinants, right? RIGHT! https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D13/Solution.hs
- June 10th, 2016: Today's #haskell problem looks at box-and-whiskers charting of data https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D10/Exercise.hs Boxes for realz, yo: https://en.wikipedia.org/wiki/Box_plot The #haskell solution has @geophf writing 'uncurry uncurry' and sincerely meaning it! 😱 https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D10/Solution.hs and box:
- June 9th, 2016: Triangles are on my mind for today's #haskell problem: https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D09/Exercise.hs … bisecting them, then trisecting them.
- June 8th, 2016: For today's #haskell problem, just what you've always wanted: MATH HOMEWORK! We find the intersection of two lines https://github.com/geophf/1HaskellADay/blob/master/exercises/HAD/Y2016/M06/D08/Exercise.hs
- ANNOUNCEMENT: lpaste.net is acting up; cloning original @1HaskellADay github repository and putting the exercise there. FYI
- June 6th, 2016: Today's #haskell problem explores superstring theory http://lpaste.net/6891096377267322880 No, it doesn't, but saying that has a certain ring to it!
- June 3rd, 2016: We saw a solution to perfect matching yesterday. For today's #haskell problem, let's efficient-ize it! http://lpaste.net/1128504074363207680
- June 1st, 2016: Today's #haskell problem is pretty much counting complements ... pretty much. http://lpaste.net/9130195410017583104 These apparently simple problems are actually rather hard. Today we have a #P-complete #haskell solution http://lpaste.net/670419007353913344