ephemient

Another bad sort

2009-11-12T04:47:23Z

Oops, I fell inactive on LJ again. At least I’m still pretty active on Stack Overflow regardless of what you see here.

Recently a whimsical question there asked for insertion sort in various languages. Pretty easy stuff, but I chose to answer with J again because my other favorite languages (Haskell, Perl, C) were already implemented.

(([<.{.@]),}.@]$:~[>.{.@])`[@.(0=#@])/ (Yes, it’s actually longer than the quicksort I mentioned a little while ago.)

Breakdown:

NB. given two arguments, return the left argument insert0 =: 4 : 'x' insert0 =: [ NB. given two arguments, return the lesser of left and head of right insert1min =: 4 : 'x <. {. y' insert1min =: [ <. {.@] NB. given two arguments, return the greater of left and head of right insert1max =: [ >. {.@] NB. recurse with insert1max and tail of right, and prepend insert1min insert1 =: 4 : 'x insert1min y , (x insert1max y) insert }. y' insert1 =: insert1min , insert1max insert }.@] insert1 =: insert1min , }.@] insert~ insert1max NB. if right has zero length, insert0, else insert1 NB. the recursive reference to insert in insert1 can be replaced by $: insert =: insert1 ` insert0 @. (0 = #@]) NB. apply insert between all elements of argument sort =: insert/

Paludis crossbuilding

2009-10-16T04:24:32Z

Gentoo has this terrific tool named crossdev.

dtlin@burnup:~$ su -c 'emerge crossdev'
… … …
dtlin@burnup:~$ crossdev
Usage: crossdev [options] --target TARGET

Options:
    --b, --binutils ver   Specify version of binutils to use
    --g, --gcc ver        Specify version of gcc to use
    --k, --kernel ver     Specify version of kernel headers to use
    --l, --libc ver       Specify version of libc to use
    -S, --stable          Use latest stable versions as default
    -C, --clean target    Uninstall specified target
    -P, --portage opts    Options to pass to emerge (see emerge(1))
    --with[out]-headers   Build C library headers before C compiler?
Stage Options:
    -s0, --stage0         Build just binutils
    -s1, --stage1         Also build a C compiler (no libc/C++)
    -s2, --stage2         Also build kernel headers
    -s3, --stage3         Also build the C library (no C++)
    -s4, --stage4         Also build a C++ compiler [default]
Extra Fun (must be run after above stages):
    --ex-only             Skip the stage steps above
    --ex-gcc              Build extra gcc targets (gcj/ada/etc...)
    --ex-gdb              Build a cross gdb
    --ex-insight          Build a cross insight
Target (-t) takes a tuple ARCH-VENDOR-OS-LIBC; see 'crossdev -t help'

(Yes, Gentoo can be a bit too… happy with colored terminals sometimes.)

If I want a cross-compiler targeting Windows, all I have to do is ensure a valid $PORTDIR_OVERLAY in /etc/make.conf, which all developers will have already, and run crossdev -t i586-mingw32msvc. Et voilà, a i586-mingw32msvc-gcc appears!

Except it only works with Gentoo’s default package manager, Portage. On my system, it’s been replaced by Paludis, “the other package mangler”. And there doesn’t seem to be documentation on how to manually take advantage of the ebuilds’ cross-building features manually. Well, I think I can remedy that.

First, set up the Paludis equivalent of $PORTDIR_OVERLAY and fill it.

dtlin@burnup:~$ su -
burnup ~ # cat >/etc/paludis/repositories/local.conf
location = /var/paludis/repositories/local
master_repository = gentoo
format = ebuild
^D
burnup ~ # mkdir -p /var/paludis/repositories/local/profiles
burnup ~ # cd /var/paludis/repositories/local
burnup local # mkdir cross-i586-mingw32msvc
burnup local # ls -d *-* >profiles/categories
burnup local # ln -fns ../../gentoo-portage/{sys-devel/{binutils,gcc,gdb},dev-util/{mingw-runtime,w32api}} cross-i586-mingwmsvc/

Next, build the stages in order.

burnup local # echo 'cross-i586-mingw32msvc/* crosscompile_opts: headers-only' >>/etc/paludis/use.conf
burnup local # echo 'cross-i586-mingw32msvc/* -* nocxx' >>/etc/paludis/use.conf
burnup local # paludis -i cross-i586-mingw32msvc/{w32api,mingw-runtime,gcc}
burnup local # sed -i '$d' /etc/paludis/use.conf
burnup local # sed -i '$d' /etc/paludis/use.conf
burnup local # paludis -i cross-i586-mingw32msvc/{w32api,mingw-runtime,gcc}

Most targets will use linux-headers instead of w32api and glibc/dietlibc/uclibc/klibc instead of mingw-runtime, but that’s the general idea.

Ah, I forgot…

burnup local # cat >>/etc/paludis/bashrc
case "${CATEGORY}/${PN}" in
    # cross-build
    cross-*/binutils|cross-*/gcc|cross-*/gdb)
        CBUILD="${CHOST}" CTARGET="${CATEGORY#cross-}"
    ;;
    cross-*/*)
        CBUILD="${CHOST}" CTARGET="${CATEGORY#cross-}"
        CC="${CTARGET}-gcc" CXX="${CTARGET}-g++" LD="${CTARGET}-ld"
    ;;
esac
^D

This may be necessary after stage 2 (but will probably fail before).

Dynamic programming to the rescue

2009-10-13T05:12:46Z

Project Euler, problem 76: “How many different ways can one hundred be written as a sum of at least two positive integers?”

Well, hmm. There are =2⁹⁹-1=633825300114114700748351602687 ways of partitioning 100. Eliminate duplicates (1+2=2+1) and we’ll have the answer… in a trillion years or so. That’s not really a good solution.

A better solution would use a better method. Does f(n,m)=, g(n)=f(n,n)-1 look usable? g(n) will take us through a n-depth call stack, forking out into O(2ⁿ) different function calls – just like before, the complexity is still too high to fit within Project Euler’s suggested "one-minute" maximum compute time.

Really?

<:+/@:([(-$:"0])>:@i.@])`(0=[)@.(0>:[)M.100

p=repeat 1:[[sum[p!!(n-i)!!i|i<-[1..min m n]]|m<-[0..]]|n<-[1..]]
main=print$pred$p!!100!!100

#include <stdio.h>
#define TOP 100
static int ways[TOP];
int main() {
    int i, j;
    for (i = 1; i < TOP; i++) {
        ways[i - 1]++;
        for (j = 0; i + j < TOP; j++)
            ways[j + i] += ways[j];
    }
    printf("%d\n", ways[TOP - 1]);
}

J, Haskell, and C respectively, all running in under one second.

Both Haskell and C have been memoized manually, while J takes advantage of M., the auto-memoizer. Now, ain’t that a handy language built-in?

Project Euler

2009-10-10T05:53:14Z

Project Euler is a countable collection of problems, requiring a mix of mathematical reasoning and machine computation to solve. Every once in a while, I get the urge to try to grow the subset of problems I’ve completed.

At only 85 solved, I’m still solidly within Level 2, which is not enough to make it into their permanent rankings yet.

For the most part, I write my calculations in Haskell, falling back to C when I’m unable to express an algorithm in anything but imperative form.

However, there is this very interesting language out there going by the un-Google-able name of J:

{:q:600851475143
+/p:i.p:^:_1[2000000
999999 A. '0123456789'
#~.,^/~2+i.99
+/1000000<,!/~i.101

5 solutions to 5 problems in 5 lines, much more succinctly stated than would be possible in any other language. (Largest prime factor of 600851475143; sum of primes under two milion; millionth permutation of 10 digits by lexical sort; how many distinct numbers n of the form x^y where 1<x,y≤100; sum of the first hundred rows of Pascal’s triangle.)

The title of last week’s post, A.~(1:I.~([:*./}:<:}.)"_1)@(i.@!@#A.]), is an implementation of bogosort, which is very much not recommended for actual use.

However, quicksort can be written as (($:@(<#[),(=#[),$:@(>#[)){.)^:(1<#); this reads as “when count greater than 1, recurse on items less than and greater than head, joined by items equal in the middle”.

Not that you’d should use that either; /:~ is the built-in sort.

Sorting factoid #1

2009-10-03T22:48:00Z

Anyone who has gone through any introductory-level computer science course has probably been exposed to a few common sorting algorithms.

#include <stdlib.h>
#include <string.h>

static void swap(int *a, int *b) {
    if (a != b) {
        int c = *a;
        *a = *b;
        *b = c;
    }
}

void bubblesort(int *a, int l) {
    int i, j;

    for (i = l - 2; i >= 0; i--)
        for (j = i; j < l - 1 && a[j] > a[j + 1]; j++)
            swap(a + j, a + j + 1);
}

void selectionsort(int *a, int l) {
    int i, j, k;
    for (i = 0; i < l; i++) {
        for (j = (k = i) + 1; j < l; j++)
            if (a[j] < a[k])
                k = j;
        swap(a + i, a + k);
    }
}

static void hsort_helper(int *a, int i, int l) {
    int j;

    for (j = 2 * i + 1; j < l; i = j, j = 2 * j + 1)
        if (a[i] < a[j])
            if (j + 1 < l && a[j] < a[j + 1])
                swap(a + i, a + ++j);
            else
                swap(a + i, a + j);
        else if (j + 1 < l && a[i] < a[j + 1])
            swap(a + i, a + ++j);
        else
            break;
}

void heapsort(int *a, int l) {
    int i;

    for (i = (l - 2) / 2; i >= 0; i--)
        hsort_helper(a, i, l);

    while (l-- > 0) {
        swap(a, a + l);
        hsort_helper(a, 0, l);
    }
}

static void msort_helper(int *a, int *b, int l) {
    int i, j, k, m;

    switch (l) {
        case 1:
            a[0] = b[0];
        case 0:
            return;
    }

    m = l / 2;
    msort_helper(b, a, m);
    msort_helper(b + m, a + m, l - m);
    for (i = 0, j = 0, k = m; i < l; i++)
        a[i] = b[j < m && !(k < l && b[j] > b[k]) ? j++ : k++];
}

void mergesort(int *a, int l) {
    int *b;

    if (l < 0)
        return;

    b = malloc(l * sizeof(int));
    memcpy(b, a, l * sizeof(int));
    msort_helper(a, b, l);
    free(b);
}

static int pivot(int *a, int l) {
    int i, j;

    for (i = j = 1; i < l; i++)
        if (a[i] <= a[0])
            swap(a + i, a + j++);

    swap(a, a + j - 1);

    return j;
}

void quicksort(int *a, int l) {
    int m;

    if (l <= 1)
        return;

    m = pivot(a, l);
    quicksort(a, m - 1);
    quicksort(a + m, l - m);
}

Sadly, unless you were paying a modicum of attention during algorithms, the equivalence between quicksort and binary search trees may have escaped you.

struct node {
    int value;
    struct node *left, *right;
};

void btreesort(int *a, int l) {
    int i;
    struct node *root = NULL, **ptr;

    for (i = 0; i < l; i++) {
        for (ptr = &root; *ptr;)
            ptr = a[i] < (*ptr)->value ? &(*ptr)->left : &(*ptr)->right;
        *ptr = malloc(sizeof(struct node));
        **ptr = (struct node){.value = a[i]};
    }

    for (i = 0; i < l; i++) {
        struct node *node;
        for (ptr = &root; (*ptr)->left; ptr = &(*ptr)->left);
        a[i] = (*ptr)->value;
        node = (*ptr)->right;
        free(*ptr);
        (*ptr) = node;
    }
}

Well, it’s true: the two are simply slightly different views of the same idea.

Quicksort	Binary tree
Choose a pivot, x.	Insert a node, x.
If y is less than x, move it to the left of x.	If y is less than x, put it in the left subtree of x.
If y is greater than x, move it to the right of x.	If y is greater than x, put it in the right subtree of x.
Sort left of x, sort right of x.	Left and right of x are binary search trees.
The resulting array is in sorted order.	Follow an in-order traversal of the tree.

And now you, too, know.

Everyone loves music, even those who can’t play

2009-10-03T17:17:56Z

http://www.flickr.com/photos/toysworkz/ / CC BY-NC-ND 2.0

Having recently “acquired” the K-ON! music collections, I’m quite disappointed to be missing (scans of) the official score book with sheet music… it sounds quite amazing.

Ah well. As I’m not a paying customer, I don’t have much room to complain. Besides, I can still enjoy videos which some talented netizens have chosen to share:

けいおん！K-ON！OP Cagayake! GIRLS　叩いてみた

けいおん！K-ON！ED Don't say "lazy"　叩いてみた

けいおん！K-ON！ふわふわ時間　叩いてみた

【ギター】Cagayake!GIRLS【教えてみる】

【ギター】Don't say "lazy"【教えてみる】

【ギター】ふわふわ時間【教えてみる】

A.~(1:I.~([:*./}:<:}.)"_1)@(i.@!@#A.])

2009-10-03T04:11:02Z

Verizon Northeast Router Failure

Our household switched over to FiOS® some while ago, for both TV and Internet. The router hung a few times early on, but that was rare, and despite the lack of certain functionality (why does it answer BOOTP without being able to configure clients?) the Actiontec MI424-WR has been pretty nice. (Hint: enable administration over port 992, apt-get install telnet-ssl, and you can dive right into the system internals, including a BusyBox shell environment. The vendor has GPL-mandated sources reasonably accessible; unfortunately the management bits are tucked away inside a monolithic OpenRG binary.)

Today held the first real disappointment in their service for me. Some major peering node went down, and bam half the Internet is inaccessible for over an hour, and horribly slow thereafter. I’m still unable to create a stable connection to my corporate VPN even now.

Not that it explains my ¾years-long absence, but even a bad excuse is a good excuse to start back up again, isn’t it?

What kind of a first-world country relies on overhead power lines?

2008-12-14T20:57:16Z

One year ago, Storm Leaves Northeast Buried in Snow:

A pre-winter blend of snow, sleet and freezing rain cut visibility and iced over highways from the Great Lakes to New England, dumping up to a foot-and-a-half of snow, stranding air and road travelers and causing an airliner to skid off a runway.
…
The storm knocked out power to thousands of homes and businesses Sunday, including 137,000 in Pennsylvania, at least 10,000 in northern New England and 20,000 in eastern Canada, authorities reported.

I’d take snow over ice any day, though. This past week, Ice storm cripples north-east US:

As many as 1m people have been left without power in the north-eastern US after one of the worst ice storms in a decade crippled the electricity grid.
States of emergency have been declared in Massachusetts, New Hampshire and in parts of Maine and New York state.
…
About 1.4 million homes and businesses across the four affected states were left without electricity on Friday morning after a widespread overnight ice storm coated power lines, pylons and trees.

<title/> is an overheard line from a conversation between people forced to temporarily relocate due to the icy storm.

I’ve actually returned home just now; power has finally been restored to my neighborhood (although reports are warning that as the ice melts, trees snapping back to their original positions could cause further outages). Our house’s heat and running water relies on electricity, so my family grabbed our stuff and escaped to a hotel in Waltham. Boston and its nearby surroundings were lucky enough to escape most of the damage. Not so much for other population centers like Worchester, Fitchburg, and Lowell, nor the little town where we live.

At least we’re not in New Hampshire. Their power grid might not be back in service until Thursday or Friday – one whole week later.

Wow, I suck.

2008-12-12T05:12:44Z

I can't say that I'll post more often, because I probably still won’t. Sorry.

Google Reader - chibiryuu's shared items does get updated frequently, with stuff I find interesting, so check there for updates if you want to poll for my aliveness. Also, if you publish a public RSS feed, thank you for making it easy to ~~stalk~~ keep in touch; if you don’t, shame on you for being anti-social.

Anyhow, I was pretty happy to find a graph of RPM over MPH for various gears of a 2006 Civic Si while randomly browsing: its data corroborates my experiences driving my car.

No, I don’t drive up to max RPMs. (Okay, I did that sometimes, but not very often. Besides, I’ve never brought 4th gear to max rev: that’s over 100mph!) It means that I now have numeric quantification for an interesting pattern I’ve noticed:

gear         2000 rpm                3000 rpm
----  -----------------------  ---------------------
1st   14 km/h = 10 km/h + 43%  13 mph = 10 mph + 34%
2nd   22 km/h = 20 km/h + 12%  20 mph = 20 mph +  5%
3rd   31 km/h = 30 km/h +  5%  29 mph = 30 mph -  2%
4th   41 km/h = 40 km/h +  4%  38 mph = 40 mph -  3%
5th   51 km/h = 50 km/h +  4%  48 mph = 50 mph -  3%
6th   73 km/h = 70 km/h +  5%  68 mph = 70 mph -  2%

Rev-matching anything outside of 1st gear is so very simple. It seemed far too coincidental when I discovered it experimentally, but the numbers back it up.

Notice how the gear ratios get tigher and tigher packed from 1st to 5th, and then there’s that big jump from 5th to 6th? When I shift by ear (RPM is correlated to pitch of engine noise), that always throws me off. Basically, shifting by a single gear usually involves a nice-sounding change in pitch — a major third or perfect fifth interval — except for that 5/6 transition, which is a dissonant tritone.

Assembly review, part 1 of 3

2008-09-23T04:09:02Z

None of this will be new to most of my readers… because I’m pretty sure I have 3 at most, and 2 of them should know this stuff already. But! This is for the sake of the third.

Say you’re given a disassembly. For example, here’s some that might be outputted by objdump -d fun.o:

fun.o: file format elf32-i386 Disassembly of section .text: 00000000 <fun>: 0: 55 push %ebp 1: 89 e5 mov %esp,%ebp 3: 53 push %ebx 4: 83 ec 08 sub $0x8,%esp 7: 83 7d 08 01 cmpl $0x1,0x8(%ebp) b: 77 08 ja 15 <fun+0x15> d: 8b 45 08 mov 0x8(%ebp),%eax 10: 89 45 f8 mov %eax,-0x8(%ebp) 13: eb 23 jmp 38 <fun+0x38> 15: 8b 45 08 mov 0x8(%ebp),%eax 18: 83 e8 02 sub $0x2,%eax 1b: 89 04 24 mov %eax,(%esp) 1e: e8 fc ff ff ff call 1f <fun+0x1f> 23: 89 c3 mov %eax,%ebx 25: 8b 45 08 mov 0x8(%ebp),%eax 28: 83 e8 01 sub $0x1,%eax 2b: 89 04 24 mov %eax,(%esp) 2e: e8 fc ff ff ff call 2f <fun+0x2f> 33: 01 c3 add %eax,%ebx 35: 89 5d f8 mov %ebx,-0x8(%ebp) 38: 8b 45 f8 mov -0x8(%ebp),%eax 3b: 83 c4 08 add $0x8,%esp 3e: 5b pop %ebx 3f: 5d pop %ebp 40: c3 ret

Let’s work step-by-step to figure out what this is.

Assumption: cdecl calling convention.

Assumption: fun is a function. Stuff other than functions can and do end up in the .text section, but this seems to disassemble just fine, so it’s probably executable code. So let’s start with a skeleton:
… fun(…);

Bytes 0-6 are the function prelude: saving the old %ebp, setting %ebp to the top of our frame, and growing our stack by 0x8.

Quick, what does the stack look like?

.... ....^-- arguments are above the return address ....<-- return address v-- top of our frame -- %ebp now points here ....<-- the eight bytes of our frame ....<-- that we just reserved... ^-- bottom of our frame -- %esp now points here

Bytes 7-c compare the literal value 1 to the 4-byte value at an address 8 bytes above %ebp — in other words, the first argument — then if (unsigned)arg1 > 1, we jump to byte 15 (ja is the unsigned version of jg, jump-if-greater.) Now we know that fun takes at least one argument, the first of which is an unsigned 4-byte value, so:
… fun(unsigned arg1, …);

Suppose we didn’t take the jump, meaning that (unsigned)arg1 ≤ 1. Bytes d-14 copy arg1 to %eax, then %eax to the bottom of our frame — that’s a local variable.
… fun(unsigned arg1, …) {     unsigned local1;     if (arg1 <= 1)         local1 = arg1;     … }

Alright, so suppose that bytes b-c do jump us to 15. Bytes 15-24 copy arg1 to %eax, subtract 2, push it on the stack, recursively call fun, then save the return value in %ebx. Bytes 25-33 copy arg1 to %eax, subtract 1, push it on the stack, recursively call fun, then add the return value to %ebx. Bytes 35-37 then take %ebx, the sum, and saves it to what we decided to call local1. From this, we can gather that fun takes a single argument, since that’s all we push onto the stack before calling it, and returns a 4-byte value, since we treat %eax as one:
unsigned fun(unsigned arg1) {     unsigned local1;     if (arg1 <= 1)         local1 = arg1;     else         local1 = fun(arg1 - 2) + fun(arg1 - 1);     … }

Bytes 38-40 copy local1 to %eax — the return register — then go through the standard teardown of our frame and return. We’ve completed analyzing this function:
unsigned fun(unsigned arg1)     unsigned local1;     if (arg1 <= 1)         local1 = arg1;     else         local1 = fun(arg1 - 2) + fun(arg1 - 1);     return local1; }

That looks very familiar… almost like a naïve Fibonacci number generator! In fact, if we write this:

unsigned fib(unsigned n) { if (n <= 1) return n; return fib(n - 2) + fib(n - 1); }

and pass it through gcc -S, it outputs this:

.file "fib.c" .text .globl fib .type fib, @function fib: pushl %ebp movl %esp, %ebp pushl %ebx subl $8, %esp cmpl $1, 8(%ebp) ja .L2 movl 8(%ebp), %eax movl %eax, -8(%ebp) jmp .L4 .L2: movl 8(%ebp), %eax subl $2, %eax movl %eax, (%esp) call fib movl %eax, %ebx movl 8(%ebp), %eax subl $1, %eax movl %eax, (%esp) call fib addl %eax, %ebx movl %ebx, -8(%ebp) .L4: movl -8(%ebp), %eax addl $8, %esp popl %ebx popl %ebp ret .size fib, .-fib .ident "GCC: (GNU) 4.2.4 (Gentoo 4.2.4 p1.0)" .section .note.GNU-stack,"",@progbits

So we pretty much nailed it on the head. (As to be expected from a simple example like this.)

Bleh

2008-06-27T02:10:48Z

So I'm driving home from work today, and being distracted because the cold engine's autochoke makes the shift points feel funny. As I exit the parking lot and get onto the road, BOOM. I've hit the curb.
W. T. F. I drive this way *every single (week)day* and never does this happen.
Half a mile down the road, I realize, "oh %$#@, the tire's flat". So I pull off onto some random driveway and change to the spare, but GYAAARGH it sucks.

Last night I tried beating Metroid Prime 3 again. I've been stuck on the final boss for months now. After another series of failed attempts, I went upstairs to beat on the walls instead. Much less painful.

Dear old laptop, you're supposed to be high-quality hardware. Why are you breaking? The keyboard has been on the fritz for the past week or so, and is now totally dead.

Other shoddy hardware: the LCD hooked up to my desktop started dying last year, unable to sync the video signal, and it's gotten worse to the point where it will no longer display an image.

However, unlike the above complaints, this last one has actually been resolved: today I have a new Acer P223Wwd, veeery nice.

Birth of a new in-joke

2008-04-29T00:13:45Z

貓

rotfl.

I feel like if I don’t explain, those who weren’t there will be utterly confused by this post. But it’s not funny enough to warrant an explanation…

So I once again missed my weekly post, oops. Some past events:

Ubuntu 8.04 Hardy Heron is released. Fedora 9 is delayed by two weeks.
That being said, I’ve dropped both Ubuntu and Fedora for my own personal use, as both have demoted PowerPC support. Now going Debian and Gentoo all the way! Even if releases are slow, at least they’re still well-maintained.
A couple weeks ago, I bought a new car. Vroom vroom. For those of you who want to borrow it to learn how to drive a standard: get ’yer own! ;)
Current soundtrack in my car: Metroid Metal. This marks the first music I’ve actually paid for in… a long time.
I am 90% through Gitaroo Man for PS2 on normal mode. So hard. Somebody needs to help me beat that un-frigging-believably impossible last level.

The end. Well, there’s probably other interesting things that have happened, but nothing immediately recallable. Hurray for having a sieve-like memory.

Upon exiting “Forbidden Kingdom”

2008-04-19T03:58:49Z

me: What did we learn about mythology?
poo-chan: Nothing.
khan: It’s freely interchangable.

(correct me if I got your lines backwards…)

Awesome misconceptions

2008-04-13T12:07:56Z

No, Poodle, you don’t need a special license to drive a stick shift.

Linkage

2008-04-08T00:56:29Z

Via Lemonodor:

Via elfs: Is homophobia associated with homosexual arousal?

On that note, via Biella Coleman: Major breakthrough in Christian genetics.

Okay, enough of that.

Back in the day, I used to visit a bunch of websites regularly. This list of websites went through several revisions.

Version 0: Whatever I remembered. Unfortunately, I have a very porous memory.
Version 1: I kept a master list of “interesting stuff” in a HTML file in my homedir. This kinda worked, but would get out of sync between my different computers, and occasionally was lost when I accidentally deleted it or when a hard disk crashed.
Version 2: del.icio.us. It was pretty good; I still use it for keeping up with webcomics which don’t all have feeds.
Version 3: Akregator, a news feed reader for KDE. It still had the problem of being out-of-sync between different machines and being lost in hard disk crashes.
Version 4: Google Reader. Not only is it a wonderful interface I can access from anywhere, from almost any browser (not very compatible with Opera and Konqui, but works fine on my n810), but also it’s got better keyboard shortcuts than most desktop feed readers! Soon, Akregator synchronization with Google Reader will make life even more awesome.

As a side-effect of moving to news feed readers, though, I’ve been dropping any blog or site which lacks public RSS/Atom feeds. Any former friend on Xanga/LJ who doesn’t have a public feed: dropped. Any news site which doesn’t have a public feed: dropped. Any … well, you get the point. Webcomics are an exception, because too many that I don’t want to give up quite yet are feedless.

(BTW, Poodle! Write a RSS/Atom generator for your blog already!)

So what do I follow nowadays? Lots of math and CS blogs; development of Linux, KDE, Gnome, Haskell, Lisp, Perl, Ruby, etc., tech news like ars and Phoronix, and…

In the “cute” folder: Cute Overload, I CAN HAS CHEEZBURGER?, Lambdacats, Let’s be friends (hasn’t updated in a while), Meme Cats (hasn’t updated in a while), Stuff On My Cat, and The FAIL Blog, which isn’t cute, but falls into the general category of image macros, and is horribly amusing.

Seriously, I do not consume caffeine

2008-04-02T00:54:17Z

I’m back?

2008-03-31T01:33:15Z

I missed the LiveJournal content strike. Or maybe I participated in it, since I was too busy to be using LJ…

On Wednesday I went to a piano recital held by an acquiantance I haven’t seen since high school; there were lots of other people there that I haven’t seen in ages, mostly former classmates, but I ran into my old boss from a previous job too. Needless to say, there were lots of people whose faces or names (or both) I’d forgotten in the intervening years… sigh. At least the music was wonderful and amazing.

I found a pack of simfiles that turned out to be a lot of fun.

A couple weekends ago, Khan got Smash Bros. Brawl and invited Poodle, ’baasan, and I to come over and play. We ended up playing all night, it was pretty awesome. Last weekend J and I raided Khan’s for the Wii (Smash) and PS2 (Katamari Damacy), that was great too. On the downside, it means that I’ve been missing my weekly dose of Metroid Prime 3 and Hayate no Gotoku for a while now…

This weekend, I drove down to J’s place to replace a computer fan that had died a horrible screechy death. We dragged Poodle along and attended the local sci-fi/fantasy/anime/gaming convention. I came back with a wallet about $100 lighter (in exchange for manga; GSC Revised 1-4 and Translucent 2-3) and a few sticks of Pocky from winning at the 2-hour “Name That [Anime/J-Pop/Game] Tune” panel. (Not to brag, but I won quite overwhelmingly. It was great fun.) Most ~~important~~awesomest of all, though, we attended a panel by the artists/writers of The Devil’s Panties, Questionable Content, Minimalist Stick Figure Theatre, and xkcd, and I got to play some DDR. I got A’s and B’s on 1 2 3 4 while J and Poodle switched off. Lazy slackers :P

Smorgasbord

2008-03-12T00:28:53Z

ephemient
http://maria-sama.rightstuf.com/
wow
add up the prices for the preorders, comes to about $100 for all three seasons
khan32k1
whoa
rightstuf has marimite?
ephemient
they do now
khan32k1
hmm
i'll have to preorder sometime in june
ephemient
why in june?
khan32k1
comes out in july
khan32k1
man
I want marimite
ephemient
hehe
judging by the responses on AoD, ANN, ALC ML, /u/, etc... I think RightStuf got like thousands of preorders as soon as it was announced
khan32k1
marimite is a really popular series
ephemient
for a series with no action and fairly low-key humor and other lacks of common exciting features, it's pretty darn popular
I mean, it's really just a (good) slow character drama, right?
khan32k1
heh
yeah

[ ｳｯｰｳｯｰｳﾏｳﾏ(ﾟ∀ﾟ) a.k.a. Caramelldansen is eating my brain.]

I’m considering buying a VPS from Layershift or Linode. Not having a school UNIX account means that the number of Linux machines I can play around in is limited to the number of machines in my home, and these guys have way more bandwidth than I do.

Also stole dad’s PCI System Architecture and Understanding the Linux Kernel books while he’s on a ~~vacation~~ business trip. (His car, too.)

Aside from the fact that they presently make up at least a quarter of my real-life manga collection, what do these series have in common?
Hana-Kimi, Kashimashi, Ouran High School Host Club, Pretty Face, W Juliet, Yubisaki Milk Tea
(Heck, a couple pages in the first volumes of Hayate the Combat Butler and One Thousand and One Nights (the manhwa) qualify too.)
Man, can I pick ’em or what?

Epic

2008-03-04T03:11:20Z

Watching Moyashimon right now. Up to episode 10.
ROTFL. Kei pulls it off even better than Ayumi Saitō.
(Spoiler warnings if you click through to the Wikipedia links, of course.)

It’s easier to post videos than to think of stuff to write

2008-02-29T02:24:03Z

Taking down a cabbage with a tennis ball cannon:

Taking down a tree with a gatling gun:

ephemient @ 2008-02-22T20:43:00

2008-02-23T01:44:24Z

Oops, missed my self-inflicted “post at least once a week” schedule.

To make up for it, here is a video:

ephemient @ 2008-02-14T15:36:00

2008-02-14T20:37:11Z

Living in a material world

2008-02-14T03:17:09Z

Being a full-time employee is weird. I get semi-weekly paychecks, health insurance, retirement funds, and daily snail-mail offers for pre-approved credit cards.

20% of my income goes to taxes.
25% of my income goes to savings.
A small portion goes towards student loans. This proportion will rise as the grace periods on various loans expire.
A majority of the remainder goes to household expenses.

I have a new Nokia n810. I’m not sure how much Verizon is charging me for GPRS usage, but most of the time I use WiFi. Works awesomely well.

As it is no longer practical for Dad and I to carpool to work, I need to procure some means of personal transportation. Sadly, nobody makes good, cute cars anymore. The VW Bug is too unreliable, the Cooper is too expensive, the Miata is too small. The RAV4 was cute for one generation, but then they steroid-ized it. I am strongly considering the Civic, though I’m disappointed by how it got fatter in 2001 and restyled in 2006.

Relatedly, planned tasks for the house are a garage expansion, driveway repavement, media center, repainting, re-roofing, …

And I want to upgrade my desktop, since I bought UT3 but am unable to play due to system specs.

Infrequently Asked Questions

2008-02-14T02:34:31Z

There are many FAQs but not many IAQs.

Sometimes they are sincerely helpful. Actually, this is a list of ”infrequently answered questions”, not “infrequently asked questions”.
Sometimes they are playful misdirections. Regardless of experience, anybody can tell at a glance not to trust its advice at face value.
And sometimes they are genuinely deleterious. Those who know better will laugh their heads off, and those who don’t, will be completely confused.

Happy New Year!

2008-02-07T03:33:25Z

Oh, my poor neglected blog.

[Chinese] New Year resolutions aren’t part of tradition, are they? Ah well.

I resolve to post something interesting (to me, anyhow) at least once a week. This week’s:

Martin Gardner's Rendition of the Laffer Curve, licensed cc-by