logs from today's meeting
inimino
And below:
2009 Mar 08 23:04:05 <inimino> it looks like 4pm PST has arrived
2009 Mar 08 23:05:02 <aamar> Ready to start?
2009 Mar 08 23:05:16 <inimino> actually I guess it's PDT now
2009 Mar 08 23:05:25 <inimino> yeah
2009 Mar 08 23:06:19 <inimino> I wonder if the time change is going to throw anyone
2009 Mar 08 23:06:42 <inimino> I didn't think about it until just now
2009 Mar 08 23:07:13 <inimino> ok, so what are we starting with?
2009 Mar 08 23:07:27 <inimino> leftovers from the from the last section wasn't it?
2009 Mar 08 23:09:15 <aamar> 1.45
2009 Mar 08 23:09:26 <inimino> ok
2009 Mar 08 23:09:44 <inimino> ah, right
2009 Mar 08 23:09:47 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_1/1.45
2009 Mar 08 23:10:40 <inimino> did anyone else do 1.45?
2009 Mar 08 23:11:01 <inimino> should we wait another hour?
2009 Mar 08 23:11:11 <aamar> http://mibbit.com/pb/YlGkdF
2009 Mar 08 23:11:26 <aamar> Alternately, we could move on to 2.1 directly.
2009 Mar 08 23:11:34 <mariorz> i didnt finish those last problems
2009 Mar 08 23:11:44 <inimino> oh
2009 Mar 08 23:11:51 <mariorz> but am looking over your solutions
2009 Mar 08 23:12:10 <inimino> aamar: looks like we came to the same conclusion
2009 Mar 08 23:12:12 <mariorz> also not sure how peoepl handled the time change
2009 Mar 08 23:12:13 <aamar> yes
2009 Mar 08 23:12:16 <mariorz> as its not universal and all
2009 Mar 08 23:12:49 <aamar> a few regulars appear not here -- nicou, chrisconley
2009 Mar 08 23:13:08 <mariorz> chrisconley is here
2009 Mar 08 23:13:16 <aamar> albeit quiet
2009 Mar 08 23:13:23 <mariorz> nicou-not-here is not
2009 Mar 08 23:13:24 <inimino> mariorz: yeah, I'm a little worried about that time change
2009 Mar 08 23:13:31 <inimino> maybe we should wait an hour
2009 Mar 08 23:13:48 <mariorz> chrisconley jsut answerd some moments ago
2009 Mar 08 23:14:14 <inimino> yeah, but not since then, maybe he stepped away
2009 Mar 08 23:14:21 <mariorz> t
2009 Mar 08 23:14:37 <mariorz> well i have something that is not specific to an ex
2009 Mar 08 23:14:44 <inimino> ok, shoot
2009 Mar 08 23:14:52 <mariorz> maybe im not groking it right
2009 Mar 08 23:15:04 <mariorz> but my mind fails to be boggled by the represent data as procs
2009 Mar 08 23:15:36 <inimino> boggle in the mind of the beholder
2009 Mar 08 23:15:37 <mariorz> i mean its really being stored as data in the end
2009 Mar 08 23:15:50 <mariorz> only not the form of data youre getting out
2009 Mar 08 23:16:07 <inimino> well, all programs are actually data
2009 Mar 08 23:16:22 <chrisconley> sorry, i'll probably be in and out tonight
2009 Mar 08 23:16:56 <inimino> chrisconley: oh, ok, we were just discussing waiting another hour due to the timechange
2009 Mar 08 23:18:14 <inimino> mariorz: I mean a running program is "just data" in some sense
2009 Mar 08 23:18:33 <chrisconley> yeah, it looks like it's only 23:18 gmt
2009 Mar 08 23:18:36 <mariorz> inimino: i can see that
2009 Mar 08 23:18:53 <inimino> but there are differences in that most programming languages limit the ways you can edit a running program
2009 Mar 08 23:29:25 -=- bartek_ is now known as bartek
2009 Mar 08 23:30:38 <aamar> Okay, restarting in 30 mins...
2009 Mar 08 23:30:54 -*- inimino puts on some tea
2009 Mar 08 23:31:25 <aamar> In the meantime, here's my 1.46: http://mibbit.com/pb/95cwDc
2009 Mar 08 23:31:40 -*- offby1 ponders tea too
2009 Mar 08 23:31:41 <aamar> same as inimino's but a little clunkier
2009 Mar 08 23:32:06 <inimino> mines here: http://inimino.org/~inimino/projects/2009/SICP/chap_1/1.46
2009 Mar 08 23:32:23 <inimino> and on the wiki: http://inimino.org/SICP-wiki/doku.php?id=exercise_1.46
2009 Mar 08 23:32:28 <inimino> with a question
2009 Mar 08 23:33:13 <inimino> if anyone thought of a solution
2009 Mar 08 23:43:02 <inimino> hm, my 1.46 was wrong
2009 Mar 08 23:45:32 <aamar> what's wrong in it?
2009 Mar 08 23:48:19 <aamar> Oh, sqrt needs a starting amount
2009 Mar 08 23:48:46 <inimino> I forgot to apply the function returned by iterative-improve
2009 Mar 08 23:48:53 <aamar> Similarly, fixed-point should use the first-guess
2009 Mar 08 23:49:11 <inimino> oh crap, I did it in sqrt too
2009 Mar 08 23:49:26 <inimino> I only noticed the second error
2009 Mar 08 23:49:53 <inimino> I was frustrated by that problem since I couldn't find a way to work around calling f twice
2009 Mar 08 23:51:34 <aamar> I don't see how you can avoid it, if you break up the arguments into improve and good-enough
2009 Mar 08 23:51:44 -*- inimino fixes the other half of 1.46
2009 Mar 08 23:52:04 <inimino> we both used an unnecessary lambda in 1.46 but in different places
2009 Mar 08 23:52:12 <inimino> aamar: yeah, me neither
2009 Mar 08 23:52:24 <aamar> Yes, I see that now. Helpful.
2009 Mar 08 23:52:32 <inimino> unless you had a shared variable between the two
2009 Mar 08 23:53:02 <inimino> but we don't have that yet
2009 Mar 08 23:53:16 <aamar> right
2009 Mar 09 00:07:09 <aamar> Okay, should we get going towards 2.1?
2009 Mar 09 00:07:46 <mariorz> yes
2009 Mar 09 00:08:04 <inimino> yeah
2009 Mar 09 00:08:05 <mariorz> everyone around?
2009 Mar 09 00:08:12 <Gracenotes> inimino :X
2009 Mar 09 00:08:19 <Gracenotes> :)
2009 Mar 09 00:08:29 <inimino> you're here too? :)
2009 Mar 09 00:08:44 <Gracenotes> yep. I idle about, reading conversations mostly
2009 Mar 09 00:09:19 <inimino> cool :)
2009 Mar 09 00:09:56 <Gracenotes> I have yet to learn Scheme very well, but I'm familiar with a few other functional languages
2009 Mar 09 00:10:17 <inimino> yeah I see you in #haskell too
2009 Mar 09 00:10:39 <Gracenotes> :)
2009 Mar 09 00:10:49 <inimino> we're just working through SICP
2009 Mar 09 00:11:05 <inimino> we're reviewing 2.1 today
2009 Mar 09 00:11:46 <inimino> anyway...
2009 Mar 09 00:11:51 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.1
2009 Mar 09 00:12:14 <inimino> there's mine
2009 Mar 09 00:12:20 <inimino> chrisconley: you around?
2009 Mar 09 00:12:30 <inimino> nicou-not-here seems to be not here...
2009 Mar 09 00:12:54 <chrisconley> yeah, but i may still have to jump out
2009 Mar 09 00:13:05 <inimino> ok
2009 Mar 09 00:13:06 <mariorz> http://github.com/mariorz/sicp/blob/be559f7e20b8ae1690008f5af6e488f74520ef1f/2.ss#L49
2009 Mar 09 00:14:22 <inimino> mariorz: yours and mine look much the same
2009 Mar 09 00:14:57 <mariorz> inimino: yep, i based mine on the final example though
2009 Mar 09 00:15:07 <inimino> the final example?
2009 Mar 09 00:15:21 <mariorz> the one that reduces the fractions
2009 Mar 09 00:15:32 <inimino> oh yeah, I noticed you reduced them
2009 Mar 09 00:15:54 <chrisconley> http://github.com/chrisconley/sicp-exercises/blob/97744b766fca1c66d34d5a5e5c84b652a6432a9c/chapter2/ex2-01.ss
2009 Mar 09 00:16:01 <aamar> http://mibbit.com/pb/7iKEpo
2009 Mar 09 00:17:32 <aamar> chrisconley: you determine sign but where do you use that?
2009 Mar 09 00:18:11 <chrisconley> hehe, yeah that looks a little fishy
2009 Mar 09 00:18:18 <chrisconley> i thought i had it working...
2009 Mar 09 00:19:42 <inimino> well those are all rather different, wow
2009 Mar 09 00:19:50 <chrisconley> i think i may have not saved my final version
2009 Mar 09 00:20:42 <mariorz> aamar is simiar to ours
2009 Mar 09 00:21:02 <inimino> looks like the problem didn't really say if the reduction was required or not
2009 Mar 09 00:21:03 <mariorz> the xor you never used?
2009 Mar 09 00:21:25 <inimino> everyone else did that but me which is why mine is so short
2009 Mar 09 00:21:58 <aamar> I didn't use the xor, you're right... needed it for an earlier version.
2009 Mar 09 00:22:08 <chrisconley> http://pastie.org/411263
2009 Mar 09 00:22:11 <aamar> Mine is conceptually similar to mariorz's solution
2009 Mar 09 00:22:22 <chrisconley> github seems to be lagging again, the above link is my updated make-rat
2009 Mar 09 00:23:21 <inimino> that one looks right
2009 Mar 09 00:23:38 <inimino> 2.2?
2009 Mar 09 00:23:50 <aamar> chrisconley, okay, so that is equivalent to mine as well
2009 Mar 09 00:24:35 <chrisconley> aamar: yeah
2009 Mar 09 00:24:43 <inimino> I took the part about the reducing version of make-rat as a parenthetical remark
2009 Mar 09 00:24:59 <inimino> so I based the improvement on the earlier example
2009 Mar 09 00:25:10 <inimino> I guess the problem should specify
2009 Mar 09 00:25:54 -*- inimino wonders how to report bugs in the book
2009 Mar 09 00:27:07 <inimino> anything else on 2.1?
2009 Mar 09 00:27:41 <chrisconley> upwards and onwards http://github.com/chrisconley/sicp-exercises/blob/97744b766fca1c66d34d5a5e5c84b652a6432a9c/chapter2/ex2-02.ss
2009 Mar 09 00:28:14 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.2
2009 Mar 09 00:29:01 <aamar> http://mibbit.com/pb/YmlQHL
2009 Mar 09 00:29:09 <mariorz> http://github.com/mariorz/sicp/blob/be559f7e20b8ae1690008f5af6e488f74520ef1f/2.ss#L88
2009 Mar 09 00:29:19 <mariorz> bah github is not displaying my pushes today
2009 Mar 09 00:29:36 <mariorz> whats up with that
2009 Mar 09 00:29:48 <chrisconley> yeah i'm seeing some delay too-what a pain
2009 Mar 09 00:30:02 <inimino> chrisconley: yours and mine are pretty much identical
2009 Mar 09 00:30:41 <chrisconley> yeah as is aamar's, i guess this was pretty straight forward
2009 Mar 09 00:30:41 <inimino> aamar: yours and mine even more so
2009 Mar 09 00:30:49 <mariorz> theyre all the same
2009 Mar 09 00:30:52 <mariorz> yep
2009 Mar 09 00:31:20 <inimino> ok
2009 Mar 09 00:31:25 <inimino> 2.3
2009 Mar 09 00:31:33 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.3
2009 Mar 09 00:31:34 <chrisconley> http://github.com/chrisconley/sicp-exercises/blob/97744b766fca1c66d34d5a5e5c84b652a6432a9c/chapter2/ex2-03.ss
2009 Mar 09 00:31:35 <mariorz> http://github.com/mariorz/sicp/blob/be559f7e20b8ae1690008f5af6e488f74520ef1f/2.ss#L109
2009 Mar 09 00:31:56 <chrisconley> i didn't get why they wanted us to use the hint
2009 Mar 09 00:32:37 <inimino> so we didn't have to redine a point, I assumed
2009 Mar 09 00:32:48 <inimino> redefine
2009 Mar 09 00:33:03 <chrisconley> i'm double checking but i don't think i used points
2009 Mar 09 00:33:27 <mariorz> yeah neither did i
2009 Mar 09 00:33:28 <chrisconley> all you need are lengths to figure out area and perimeter
2009 Mar 09 00:33:33 <mariorz> yup
2009 Mar 09 00:33:36 <inimino> well yeah
2009 Mar 09 00:33:49 <chrisconley> they should've asked to compute the midpoint of the rectangle
2009 Mar 09 00:33:54 <mariorz> i used one point scratch that
2009 Mar 09 00:33:58 <mariorz> for the top-left pos
2009 Mar 09 00:33:59 <inimino> but you have to come up with two represtations
2009 Mar 09 00:34:09 -*- inimino can't type
2009 Mar 09 00:34:18 <chrisconley> yeah, i didn't :)
2009 Mar 09 00:34:26 <chrisconley> well i started to
2009 Mar 09 00:34:29 <inimino> I guess they expected you to use points in one of them
2009 Mar 09 00:34:37 <mariorz> but yeah unneeded
2009 Mar 09 00:36:13 <inimino> hm...
2009 Mar 09 00:36:32 <inimino> chrisconley: I don't understand how your make-rect actually defined a rectangle in the plane
2009 Mar 09 00:36:47 <chrisconley> mariorz: i started going down the route you did with one point and two lengths
2009 Mar 09 00:36:48 <aamar> http://mibbit.com/pb/wmilAx -- 2.3 (zoned out for a sec there)
2009 Mar 09 00:37:06 <aamar> My alternate representation is a line and a point not on the line
2009 Mar 09 00:37:20 <chrisconley> ahhh, there i go again not reading directions carefully
2009 Mar 09 00:37:28 <chrisconley> i didn't see the "in a plane" part
2009 Mar 09 00:37:41 <inimino> ah
2009 Mar 09 00:38:01 <mariorz> i guess thats why i left that top-left point
2009 Mar 09 00:38:47 <chrisconley> yeah
2009 Mar 09 00:39:48 <inimino> mariorz: I like your solution
2009 Mar 09 00:40:06 <mariorz> thx
2009 Mar 09 00:41:27 <chrisconley> 2.4?
2009 Mar 09 00:41:46 <inimino> aamar: looks like you'd have to add some checks for invalid pairs of lines
2009 Mar 09 00:42:43 <aamar> inimino: yes, error checking would probably be warranted
2009 Mar 09 00:43:06 <inimino> ok, yeah 2.4
2009 Mar 09 00:43:10 <aamar> 2.4 -- http://mibbit.com/pb/PcC8ds
2009 Mar 09 00:43:13 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.4
2009 Mar 09 00:43:40 <mariorz> http://github.com/mariorz/sicp/blob/be559f7e20b8ae1690008f5af6e488f74520ef1f/2.ss#L158
2009 Mar 09 00:43:43 <chrisconley> http://github.com/chrisconley/sicp-exercises/blob/97744b766fca1c66d34d5a5e5c84b652a6432a9c/chapter2/ex1-04.ss
2009 Mar 09 00:43:47 <mariorz> theyre all gogin to be the same here to no
2009 Mar 09 00:44:30 <mariorz> yup
2009 Mar 09 00:44:53 <chrisconley> yeah, this took me a little to go through the substitutions though with all those lambdas
2009 Mar 09 00:45:23 <inimino> yeah, likewise
2009 Mar 09 00:46:03 <inimino> looks like we all got exactly the same answer though
2009 Mar 09 00:46:08 <chrisconley> yeah
2009 Mar 09 00:46:28 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.5
2009 Mar 09 00:46:37 <mariorz> http://pastebin.com/m510bbfcd
2009 Mar 09 00:46:37 <chrisconley> http://github.com/chrisconley/sicp-exercises/blob/97744b766fca1c66d34d5a5e5c84b652a6432a9c/chapter2/ex1-05.ss
2009 Mar 09 00:46:44 <aamar> 2.5 -- http://mibbit.com/pb/GmiXcG
2009 Mar 09 00:46:46 <inimino> ah, this one was cool
2009 Mar 09 00:47:28 -*- inimino really needs to make clicking on links from IRC work again
2009 Mar 09 00:47:30 <chrisconley> i got a couple of hints from eli.thegreenplace.net on this and the net :(
2009 Mar 09 00:47:34 <mariorz> nice one inimino
2009 Mar 09 00:47:39 <chrisconley> next not net
2009 Mar 09 00:47:51 <inimino> thanks
2009 Mar 09 00:48:50 <mariorz> inimino you using the terminal?
2009 Mar 09 00:48:57 <inimino> yeah
2009 Mar 09 00:49:05 <mariorz> you're (as per irc and clicking links)
2009 Mar 09 00:49:10 <mariorz> on a mac by any chance?
2009 Mar 09 00:49:18 <inimino> I had a plugin that handled it
2009 Mar 09 00:49:45 <inimino> no, on a debian server in a screen session which I'm logged into over ssh
2009 Mar 09 00:49:52 <mariorz> on a mac you can do option click (two finget click on trackpad) on the url and there is an open url option
2009 Mar 09 00:50:14 <mariorz> yeah im logged over ssh to my screen session
2009 Mar 09 00:50:23 <mariorz> im talking about locally in your terminal window
2009 Mar 09 00:50:28 <inimino> yeah, Gnome Terminal emulator had that
2009 Mar 09 00:50:38 <inimino> but I'm using urxvt, which doesn't
2009 Mar 09 00:50:41 <aamar> mariorz -- does yours work ?
2009 Mar 09 00:51:00 <mariorz> aamar: yeah
2009 Mar 09 00:51:03 <aamar> meaning your solution to 2.5
2009 Mar 09 00:51:16 <mariorz> aamar: yeah, i think so, why?
2009 Mar 09 00:51:21 <inimino> looks like it should
2009 Mar 09 00:51:25 <stu8ball> http://www.jukie.net/~bart/blog/20070503013555
2009 Mar 09 00:52:08 <inimino> mariorz's was confusing until I noticed the order of the arguments to factred
2009 Mar 09 00:52:28 <mariorz> inimino: yeah that part i didnt like
2009 Mar 09 00:52:58 <mariorz> was trying to come up with a solutoin that only required test but coudlnt come up with anyhting good
2009 Mar 09 00:55:07 <inimino> aamar: divides-times is nice
2009 Mar 09 00:55:21 <inimino> that's way better than "helper" which is all I came up with
2009 Mar 09 00:56:02 <chrisconley> i unfortunately gotta run; i'll keep my eye out for the next meeting and what it covers; thanks!
2009 Mar 09 00:56:03 <inimino> your function has a cleaner signature too
2009 Mar 09 00:56:18 <inimino> chrisconley: see you next time!
2009 Mar 09 00:57:16 <mariorz> yeah +1 for aamar's
2009 Mar 09 00:57:34 <inimino> stu8ball: that urxvt thing looks great, I'll have to look into it
2009 Mar 09 00:58:08 <aamar> thx
2009 Mar 09 00:58:08 <aamar> Okay, now I've understood mariorz's as well.
2009 Mar 09 00:58:15 <aamar> 2.6?
2009 Mar 09 00:58:40 <inimino> ok
2009 Mar 09 00:58:51 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.6
2009 Mar 09 00:59:33 <mariorz> this one was hard
2009 Mar 09 00:59:45 <mariorz> looking at the wikipedia page helped
2009 Mar 09 00:59:52 <inimino> oh yeah, this one
2009 Mar 09 01:00:01 <inimino> this was fun :-)
2009 Mar 09 01:00:04 <aamar> http://mibbit.com/pb/cE2pM8
2009 Mar 09 01:00:15 <inimino> I didn't check my answers so they may be wrong
2009 Mar 09 01:00:30 <mariorz> thyre right inimino
2009 Mar 09 01:00:43 <mariorz> though i coudlnt figure them out after looking at them until i read wikipedia
2009 Mar 09 01:00:48 <mariorz> even after*
2009 Mar 09 01:01:11 <inimino> ok
2009 Mar 09 01:01:40 <mariorz> and aamar has the same
2009 Mar 09 01:01:49 <inimino> yep, same
2009 Mar 09 01:02:04 -*- inimino checks chrisconley's github
2009 Mar 09 01:03:13 <inimino> looks like he didn't finish it
2009 Mar 09 01:03:18 <inimino> anybody else?
2009 Mar 09 01:03:30 <inimino> should we work through it?
2009 Mar 09 01:03:50 <mariorz> would be nice if someone explained it
2009 Mar 09 01:03:53 <inimino> this one was more challenging than most of them I thought
2009 Mar 09 01:04:00 <inimino> I'll give it a shot
2009 Mar 09 01:04:51 <inimino> a Church numeral is a function which takes two armguments
2009 Mar 09 01:05:06 <inimino> it applies the first argument to the second argument n times
2009 Mar 09 01:05:39 <inimino> so the first one is (lambda (f) (lambda (x) x))
2009 Mar 09 01:05:56 <inimino> that's "zero"
2009 Mar 09 01:06:11 <inimino> which applies f to x 0 times
2009 Mar 09 01:06:29 <inimino> that's why one has (f x) inside it
2009 Mar 09 01:06:31 <mariorz> k
2009 Mar 09 01:06:38 <inimino> and two has (f (f x)) inside it
2009 Mar 09 01:06:56 <inimino> so if we look at the definition of add
2009 Mar 09 01:07:00 <aamar> so two is applying the function twice, three is applying the function 3 times etc.
2009 Mar 09 01:07:06 <inimino> yeah
2009 Mar 09 01:07:08 <mariorz> the number of f that encapsulate x represent the number no?
2009 Mar 09 01:07:15 <aamar> yes
2009 Mar 09 01:07:16 <inimino> yes
2009 Mar 09 01:07:22 <mariorz> k
2009 Mar 09 01:07:25 <inimino> so if you look at add
2009 Mar 09 01:07:32 <inimino> you have n and m
2009 Mar 09 01:07:42 <inimino> each of these is a Church numeral
2009 Mar 09 01:08:02 <inimino> so what we can do with it is give it a function as an argument
2009 Mar 09 01:08:27 <inimino> and we have the function f
2009 Mar 09 01:08:53 <inimino> so on the inside you have ((m f) ((n f) x))
2009 Mar 09 01:09:11 <inimino> that's taking n of f which is the repeated application of f n times
2009 Mar 09 01:09:19 <inimino> and it's applying that to x
2009 Mar 09 01:09:49 <aamar> Here's how I tested: (((plus two two) square) 3)
2009 Mar 09 01:10:02 <aamar> and checking that against: (square (square (square (square 3))))
2009 Mar 09 01:10:02 <inimino> that's a good example
2009 Mar 09 01:10:08 <inimino> yeah
2009 Mar 09 01:10:13 <inimino> so if f is square and x is three
2009 Mar 09 01:10:36 <inimino> and n is 2, you'd expect ((n f) x) to be 91
2009 Mar 09 01:10:39 <inimino> er 81
2009 Mar 09 01:11:10 <inimino> then you take m of f, and apply that to that result
2009 Mar 09 01:11:49 <inimino> so you're adding my making sure you apply f a total of m + n times
2009 Mar 09 01:11:50 <aamar> Anything more to add?
2009 Mar 09 01:11:57 <inimino> and the rest of it is just threading the value through
2009 Mar 09 01:12:06 <inimino> that's it
2009 Mar 09 01:12:18 <inimino> did that make sense?
2009 Mar 09 01:12:24 <mariorz> ok, need to play with it a little more, but that helped
2009 Mar 09 01:12:27 <inimino> ok, cool
2009 Mar 09 01:12:28 <mariorz> thanks!
2009 Mar 09 01:12:32 <inimino> np
2009 Mar 09 01:12:39 <inimino> 2.7?
2009 Mar 09 01:12:50 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.7
2009 Mar 09 01:13:08 <mariorz> http://github.com/mariorz/sicp/blob/be559f7e20b8ae1690008f5af6e488f74520ef1f/2.ss#L233
2009 Mar 09 01:13:26 <mariorz> 2.8
2009 Mar 09 01:13:58 <aamar> http://mibbit.com/pb/yIZ9l9
2009 Mar 09 01:13:59 <inimino> oh yeah this one was trivial
2009 Mar 09 01:14:03 <inimino> 2.8
2009 Mar 09 01:14:14 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.8
2009 Mar 09 01:14:28 <mariorz> same here, all the same
2009 Mar 09 01:15:05 <inimino> yep
2009 Mar 09 01:15:29 <inimino> 2.9
2009 Mar 09 01:15:31 <mariorz> my math skillz are poor
2009 Mar 09 01:15:35 <mariorz> this is what i did
2009 Mar 09 01:15:39 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.9
2009 Mar 09 01:15:39 <mariorz> http://pastebin.com/m416731f7
2009 Mar 09 01:15:54 <aamar> http://mibbit.com/pb/SQr6aA
2009 Mar 09 01:19:08 <inimino> aamar: yours and mine are the same again
2009 Mar 09 01:19:21 <aamar> mariorz: yours basically gets to the "add" and "subtract" case.
2009 Mar 09 01:19:29 <inimino> though I think your notation was a little better
2009 Mar 09 01:20:56 <inimino> I don't understand what a and b are in mariorz's
2009 Mar 09 01:21:36 <aamar> a b are the upper and lower-bounds of segment #2, I think.
2009 Mar 09 01:22:07 <inimino> oohh
2009 Mar 09 01:22:42 <inimino> ah, ok, I get it
2009 Mar 09 01:23:00 <mariorz> yea x and a are upper bounds
2009 Mar 09 01:23:06 <inimino> yeah, seems to cover addition and subtraction (which are the same really)
2009 Mar 09 01:23:35 <inimino> ok
2009 Mar 09 01:24:12 <inimino> any questions on that one?
2009 Mar 09 01:24:45 <mariorz> im good
2009 Mar 09 01:25:23 <aamar> 2.10 -- http://mibbit.com/pb/nDiF0Y
2009 Mar 09 01:25:50 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.10
2009 Mar 09 01:26:36 <aamar> Oh, it's a lot better to trap the 0s as well.
2009 Mar 09 01:27:18 <aamar> Okay, so this one really just required adding one clause to the div-interval function.
2009 Mar 09 01:27:28 <aamar> So I don't imagine there are a lot of questions on this one.
2009 Mar 09 01:27:35 <inimino> yeah
2009 Mar 09 01:27:56 <aamar> 2.11 was one of the most difficult ones.
2009 Mar 09 01:28:21 <mariorz> this is as far as i got
2009 Mar 09 01:28:25 <inimino> I guess "if the sum of the absolute values are greater than the absolute value of the sums" is equivalent to saying that the signs are different
2009 Mar 09 01:29:32 <inimino> hm, I guess it's just aamar and I that got further?
2009 Mar 09 01:29:50 <aamar> maybe chrisconley will come back as well
2009 Mar 09 01:29:51 <inimino> maybe we should punt on the rest until next time?
2009 Mar 09 01:30:02 <inimino> he might
2009 Mar 09 01:30:35 <inimino> oh that was his solution I was looking at ,whoops
2009 Mar 09 01:31:01 <aamar> Let's push forward to 2.16.
2009 Mar 09 01:31:11 <aamar> We do have chrisconley's solution up here.
2009 Mar 09 01:31:23 <inimino> ok
2009 Mar 09 01:31:25 <inimino> yeah
2009 Mar 09 01:31:51 <inimino> alright, 2.11 then
2009 Mar 09 01:32:30 <inimino> oh yeah, this one
2009 Mar 09 01:32:36 <aamar> Oh I actually looked at chrisconley's solution set -- he only got to 2.11!
2009 Mar 09 01:32:40 <inimino> http://inimino.org/~inimino/projects/2009/SICP/chap_2/2.11
2009 Mar 09 01:32:47 <inimino> yeah, I just noticed that
2009 Mar 09 01:32:55 <inimino> and his 2.11 isn't complete
2009 Mar 09 01:33:11 <aamar> 2.11 - http://mibbit.com/pb/OR1eeT
2009 Mar 09 01:34:27 <inimino> damn
2009 Mar 09 01:34:38 <inimino> that's almost character for character the same as mine
2009 Mar 09 01:34:44 <inimino> that's uncanny
2009 Mar 09 01:35:14 <aamar> strange
2009 Mar 09 01:35:17 <inimino> we must be long-lost twins
2009 Mar 09 01:35:25 <aamar> haha
2009 Mar 09 01:35:55 <inimino> the only difference is you used ux where I used xu
2009 Mar 09 01:36:13 <inimino> and I decided that ux would be better part way through but was too lazy to change it
2009 Mar 09 01:37:15 <inimino> also I had defined positive? and negative? exactly as you have them
2009 Mar 09 01:37:42 <inimino> but then I ended up pulling them out as it made it shorter
2009 Mar 09 01:38:13 <aamar> yeah, it ends up not being so helpful for length or clarity
2009 Mar 09 01:38:20 <aamar> but I did end up leaving them in
2009 Mar 09 01:38:38 <inimino> yeah I think it's a kind of useful documentation actually
2009 Mar 09 01:39:15 <inimino> makes the logic a little easier to follow
2009 Mar 09 01:39:41 <inimino> I just went with what was shorter as I often do
2009 Mar 09 01:40:20 <inimino> alright, I guess we'll get everyone else's 2.11 and the rest next time?
2009 Mar 09 01:41:02 <aamar> Agreed.
2009 Mar 09 01:41:10 <inimino> ok
2009 Mar 09 01:41:16 <aamar> I think we got fewer people this time because we went to weekly, instead of bi-weekly.
2009 Mar 09 01:41:23 <aamar> Maybe we should resume every 2 weeks.
2009 Mar 09 01:41:36 <inimino> hm, good point
2009 Mar 09 01:42:18 <inimino> I could go either way
2009 Mar 09 01:42:23 <aamar> I.e. meet in 2 weeks and do 2.11 through 2.23 ?
2009 Mar 09 01:42:37 <aamar> I managed to do a little ahead this week, and 2.2 is very, very long.
2009 Mar 09 01:42:41 -*- inimino looks up 2.23
2009 Mar 09 01:43:13 <kandinski> woo, I am so behind
2009 Mar 09 01:43:23 <kandinski> yes, bi-weekly would be good
2009 Mar 09 01:43:25 <inimino> so that would be through 2.2.1
2009 Mar 09 01:43:32 <aamar> yes
2009 Mar 09 01:44:11 <mariorz> i thik weekly meetings are good
2009 Mar 09 01:44:54 <mariorz> maybe next sun to 2.11 to 2.16 and week after that 2.17 2.23?
2009 Mar 09 01:45:33 <inimino> I like the weekly meetings, but I'm willing to give it up if it's keeping people from attending
2009 Mar 09 01:45:34 <aamar> I'm up for it either way.
2009 Mar 09 01:45:36 <mariorz> maybe we should ask the mailing list
2009 Mar 09 01:45:46 <mariorz> same here really
2009 Mar 09 01:45:46 <inimino> agreed on the mailing list
2009 Mar 09 01:46:10 <inimino> mariorz, you want to post something about it?
2009 Mar 09 01:46:23 -*- mariorz was about to go out
2009 Mar 09 01:46:26 <inimino> s/post/email
2009 Mar 09 01:46:32 <inimino> ok, np, I'll do it
2009 Mar 09 01:46:40 <mariorz> cool, if not i can do it when i get back
2009 Mar 09 01:46:51 <aamar> ok, cool
2009 Mar 09 01:46:53 <inimino> nah, I'll send something
2009 Mar 09 01:47:02 <inimino> so next meeting TBD
2009 Mar 09 01:47:05 <mariorz> cool, so see you guys later
2009 Mar 09 01:47:12 <inimino> and watch the mailing list :)
2009 Mar 09 01:47:19 <inimino> later, all
2009 Mar 09 01:49:42 <aamar> later