关于elapses的讨论汇总 - 话题女王

全部话题 - 话题: elapses

f**c
发帖数: 791

来自主题: NewJersey版 - 闯红灯：elapsed time: 0.67 s (转载)

【以下文字转载自 Automobile 讨论区】
发信人: ffgc (■缙云山■), 信区: Automobile
标题: 闯红灯：elapsed time: 0.67 s
发信站: BBS 未名空间站 (Fri Sep 24 22:39:12 2010, 美东)
juts received ticket in mail. saw the video online :((
$85, 2 points, 2 additional insurance points
保险会长多少？any suggestion? thx

a**a
发帖数: 416

来自主题: Mathematics版 - (zz)Heroes in My Heart (50) -- to elapse

发信人: ukim (X人), 信区: Science
标题: Heroes in My Heart (50) -- to elapse
发信站: BBS 水木清华站 (Sat May 25 12:13:33 2002)

s****u
发帖数: 47

来自主题: Science版 - [FWD] Re: precise time elapsed?

Thank you guys very much. I got a lot of ideas.
I'm sorry I didn't make myself clear when asking the question.
When I said "elapsed" time, I really meant CPU time,
because I/O time is useless in my computational comparisons.
The UNIX command, time, does measure CPU time. That's good.
But I can't measure the CPU time of PART of my program, the
"core" computations, using that command.
gprof is good for program optimization. However I think that
addition of debugging codes will alter the actual tim

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

1/18/13
Distance: 1,000 yd（18X50YD+4X25YD free)
Moving Time: 16:33
Elapsed Time: 32:09
Avg Pace: 1:39 min/100 yd
Best Pace: 1:23 min/100 yd
2/19/13
Distance: 2,000 yd(100yd free, 500yd kick, 1000yd pull, 4x100 free)
Moving Time: 42:27
Elapsed Time: 47:32
Avg Pace: 2:00 min/100 yd
Best Pace: 1:30 min/100 yd
Avg Pull Pace: 2:04 min/100yd
Avg Kick Pace: 37.2 sec/length
2/20/13
Distance: 1,200 yd(3x100+18x50 free)
Moving Time: 21:00
Elapsed Time: ... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

春天一到，天气变好，游泳有点懈怠。还得接着练，希望不要荒废了。
4/4/13
Distance: 2,000 yd(100yd free, 500yd kick, 1000yd pull, 400yd free)
Moving Time: 40:48
Elapsed Time: 43:01
Avg Pace: 1:55 min/100 yd
Avg Moving Pace: 2:02 min/100 yd
PR 1000yd pull @18:58.5
4/8/13
Distance: 1,000 yd(200+8x100 free style on 2:10)
Moving Time: 18:32
Elapsed Time: 21:28
Avg Pace: 1:51 min/100 yd
Avg Moving Pace: 1:51 min/100 yd
Best Pace: 1:36 min/100 yd
4/9/13
Distance: 2,000 yd(100yd free, 500y... 阅读全帖

r***e
发帖数: 2000

来自主题: Programming版 - C 程序 clock() timer 问题

麻烦帮忙看一下这段程序用clock()的timer有什么问题。
#include
#include
#include
#include
int main()
{
clock_t start, end;
double elapse, _elapse;
struct timeval _start, _end;
gettimeofday(&_start, 0);
start = clock();
sleep(1);
end = clock();
gettimeofday(&_end, 0);
elapse = (end - start) / (double) CLOCKS_PER_SEC;
_elapse = ((_end.tv_sec - _start.tv_sec)*1000000.0
+ (_end.tv_usec-_start.tv_usec)) / 1000000.0;
printf("start: %ld, end: %ld, clocks... 阅读全帖

l*****8
发帖数: 16949

来自主题: Football版 - PM's grade of this game

Generally agree.
PM B, D: D, Coach D.
我不给D打F应给上半场打得还是相当不错的，但下半场就完全消失。
PM的进攻，不能光看简单数据（其实数据也不错，31/45, 333吗，1TD, 1 Int)。我们
分开来看看他的几个Drive:
1st QT:
1. 11 plays, 53 yards, 5:53 elapsed, FG
2. 11 plays, 96 yards, 4:36 elapsed, TD
2nd QT:
3. 3 plays, 6 yards, 1:20 elapsed, Punt. 这个没有得分主要是嘎送掉球。PM自己
责任不太大。算30%吧。
4. 3 plays, 9 yards, 1:03 elapsed, punt.这个是Call的太保守了。３个running
play,PM没啥责任。
3rd QT:
5. 10 plays, 76 yards, 5:26 elapsed, TD
4th QT:
6. 12 plays, 56 yards, 6:22 elapsed, Missed FG.这个最后一下是Collie跑错r

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

5/8/13
Distance: 2,500 yd(1000yd Free, 500yd kick, 1000yd pull)
Moving Time: 51:32
Elapsed Time: 52:38
Avg Pace: 1:55 min/100 yd
Best Pace: 1:34 min/100 yd
5/9/13
Distance: 2,500 yd(1000yd Free, 500yd kick, 1000yd pull)
Moving Time: 50:56
Elapsed Time: 52:07
Avg Pace: 1:55 min/100 yd
Best Pace: 1:29 min/100 yd
5/10/13
Distance: 1,000 yd(500yd free + 5x100yd free on 2:00)
Moving Time: 18:09
Elapsed Time: 19:48
Avg Pace: 1:49 min/100 yd
Best ... 阅读全帖

d**h
发帖数: 159

来自主题: Running版 - [合集] 【包子活动】废话少说，包子刺激大家在这个节日里继续跑

☆─────────────────────────────────────☆
dash2000 (DASH) 于 (Tue Dec 24 17:23:56 2013, 美东) 提到:
知道假期里大家准备吃吃喝喝有些懒散了，咱和减肥版学，在意志最薄弱的时候，让包
子刺激你跑得更勤快！
12/25-1/1号之间（包括25和1号），你跑一迈我给你3个伪币。10迈就是30伪币。20迈
就是60伪币，比灌水发帖赚包子来的快多了。不管速度，一迈是一迈，跑得快的效率高
，跑的慢的舍得花时间跑也一样。
上garmin log，或者treadmill的照片，新人旧人潜水员都来吧，有证据的，我都发包
子，不封顶，你的双腿是你的瓶颈，呵呵！
Edit:最后8天一结算，1月4号晚上截止报25-1号的里程。
不要局限照片了，有log贴log，没有的，报个里程，一样给包子，大过年的，不要这么
拘谨于条文了。我准备8天跑完，把跑个头summary一贴完事，领包子。
大家自己累计里程，每天几迈，最后8天一共几迈，我按大家报的发就完事了。跑步的
都很务实，都是一个脚在另一个脚之前，一步一步跑出来的。
PS... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

最近练得不少，提高不大。自我感觉稳定性有所提高，体力跟得上的话有时候还可以再
有快点。
1/28/13
Distance: 2,000 yd（100 Free, 2x500 Pull, 500 Kick, 1x100, 6x50free）
Moving Time: 46:01
Elapsed Time: 54:18
Avg Pace: 1:54 min/100 yd
Best Pace: 1:40 min/100 yd
Avg Kick Pace: 40.4sec/length
Avg Pull Pace: 34.6sec/length
划水开始比打腿快了。
1/29/13 下雪没时间多游
Distance: 650 yd
Moving Time: 12:56
Elapsed Time: 18:48
Avg Moving Pace: 1:59 min/100 yd
Best Pace: 1:40 min/100 yd
1/30/13
Distance: 2,000 yd（200 free, 10... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

2/11/13
Distance: 1,200 yd(1x200 free, 8x100 free, 4x50 free)
Moving Time: 24:52
Elapsed Time: 34:33
Avg Pace: 2:04 min/100 yd
Best Pace: 1:43 min/100 yd
Avg Strokes: 13 / length
本想连着游1650yd, 意志不坚强没push过去，只好改break down了。
2/12/13
Distance: 2,000 yd(1850+150yd free）
Moving Time: 46:21
Elapsed Time: 46:40
Avg Pace: 2:19 min/100 yd
Best Pace: 1:42 min/100 yd
刻意保持平滑，没有猛游。最后数错圈停了几秒又补了三圈。
2/13/13
Distance: 2,000 yd（200/100/50 breakdown）
Moving Time: 3... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

感谢诸位大佬鼓励，继续努力。
3/11/13
Distance: 2,000 yd(1000+2x500yd)
Time: 42:53
Moving Time: 41:24
Avg Moving Pace: 2:04 min/100 yd
Best Pace: 1:40 min/100 yd
1000yd avg pace 2:03, 500yd avg pace 2:03, 2:07, stroke count is still high
3/12/13
Distance: 2,000 yd(2x100yd free, 500yd kick, 1000yd pull, 3x100yd free)
Time: 46:14
Moving Time: 40:57
Avg Pace: 2:18 min/100 yd
Avg Moving Pace: 2:01 min/100 yd
100yd 游出了1:31，感觉小有突破。
3/13/13
Distance: 1,000 yd(2x100, 15x50,... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

4/29/13
Distance: 1,000 yd(400yd free, 6x100yd free on 2:00)
Moving Time: 18:00
Elapsed Time: 20:01
Avg Pace: 1:48 min/100 yd
Best Pace: 1:29 min/100 yd
400码7:15.7, 离6分钟近了一点。
4/30/13
Distance: 1,000 yd or 1050yd Free style
Time: 19:40
没戴garmin swim, 好像游了1050yd.
5/1/13
Distance: 2,000 yd(1100 + 400 + 5x100 on 2:00 free style)
Moving Time: 37:04
Elapsed Time: 39:36
Avg Pace: 1:51 min/100 yd
Best Pace: 1:30 min/100 yd
Total Strokes: 970
1100yd 20:... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

看着版上各位牛人的训练成绩很受刺激，也很受鼓舞，感觉提高成绩还是很有潜力可以
挖，同时也深深感受遇到各种瓶颈，希望能找到正确的路径。
12/3/12
Distance: 1,050 yd(200x1 free, 50x16 free)
Moving Time: 22:26
Elapsed Time: 35:52
Avg Pace: 3:25 min/100 yd
Avg Moving Pace: 2:05 min/100 yd
Best Pace: 1:47
SPL： 26
12/5/12
Distance: 1,750 yd(200x2, 500x1, 100x3, 50x11 free)
Moving Time: 41:28
Elapsed Time: 51:02
Avg Pace: 2:55 min/100 yd
Avg Moving Pace: 2:20 min/100 yd
Best Pace: 1:48
SPL: 26
12/6/12... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

感觉中长距离游下来不是大问题了，提高技术提高速度开始日显重要。
12/17/12
Distance: 1,000 yd（8x100, 4x50 free)
Moving Time: 20:53
Elapsed Time: 30:12
Avg Pace: 3:01 min/100 yd
Avg Moving Pace: 1:59 min/100 yd
SPL: 23
注意提高划水质量。
12/18/12
Distance: 1,100 yd（1x200, 1x300, 3x100, 6x50 free)
Moving Time: 23:03
Elapsed Time: 32:22
Avg Pace: 2:56 min/100 yd
Avg Moving Pace: 2:00 min/100 yd
SPL： 25
距离稍长划水质量显著下降。
12/19/12
Distance: 1,100 yd（1x350, 1x150, 4x100, 4x50)
Moving Time: 23:22
Elap... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

下雪杂事耽误好几天，继续补记。
1/7/13
Distance: 1,650 yd（1x200yd free, 2x300yd kick, 2x200yd pull, 3x100yd
free, 1x150yd free).
Moving Time: 37:05
Elapsed Time: 43:45
Avg Pace: 2:04 min/100 yd
Best Pace: 1:43 min/100 yd
Avg Kick Pace: 36.8sec/length
Avg Pull Pace: 33.6sec/length
1/8/13
Distance: 1,650 yd(250yd free, 550yd kick, 400yd pull,3x100yd free,
1x150yd free).
Moving Time: 38:48
Elapsed Time: 46:24
Avg Pace: 2:05 min/100 yd
Best Pace: 1:42 min/100 yd
Avg Kick P... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

从雪里爬出来，小结上周数据。体育这东西还是得多练。
2/5/13
Distance: 2,000 yd(200 free, 500 kick, 1000 pull, 3x100 free)
Moving Time: 45:43
Elapsed Time: 50:31
Avg Moving Pace: 2:15 min/100 yd
Avg Kick Pace: 39.6sec/length
Avg Pull Pace: 33.5sec/length
2/6/13
Distance: 2,000 yd(3x100 free, 500 kick, 1000 pull, 2x100 free)
Moving Time: 44:11
Elapsed Time: 49:11
Avg Moving Pace: 2:13 min/100 yd
Best Pace: 1:34 min/100 yd
Avg Kick Pace: 38.8sec/length
Avg Pull Pace: 32.2sec/length
2/7... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

3/25/13
Distance: 2,000 yd(400yd free, 500yd kick, 1000yd pull, 100yd free)
Moving Time: 42:31
Elapsed Time: 44:35
Avg Pace: 2:01 min/100 yd
测了一下400yd, 7:42, 贼慢，什么时候能游进6分钟好去跟小孩比一比。
3/27/13
Distance: 2,000 yd（1x200, 8x100 on 2:10, 2x500 free)
Moving Time: 40:17
Elapsed Time: 45:33
Avg Pace: 2:01 min/100 yd
3/28/13
Distance: 2,000 yd(1000yd free, 6x100 on 2:10, 400yd free)
Moving Time: 39:33
Elapsed Time: 44:01
Avg Pace: 1:59 min/100 yd
周三的8x100 on 2... 阅读全帖

W********n
发帖数: 254

来自主题: DotNet版 - C#版ruby太慢了

原帖在这
http://my.oschina.net/iveryang/blog/125302
还有这
http://www.oschina.net/code/snippet_186034_20776
用C# TPL算了一下只要0.28秒
static void Main(string[] args)
{
Stopwatch sw = new Stopwatch();
sw.Start();
TPL(10000000);
Console.WriteLine("TPL elapsed: " + sw.Elapsed);
sw.Restart();
NonTPL(10000000);
Console.WriteLine("Non TPL elapsed: " + sw.Elapsed);
Console.Read();
}
static void Non... 阅读全帖

s*********e
发帖数: 1051

来自主题: Statistics版 - R 有点令人失望

> n <- 1000000
> set.seed(2013)
> ldf <- data.frame(id1 = sample(n, n), id2 = sample(n / 100, n, replace =
TRUE), x1 = rnorm(n), x2 = runif(n))
> rdf <- data.frame(id1 = sample(n, n), id2 = sample(n / 100, n, replace =
TRUE), y1 = rnorm(n), y2 = runif(n))
>
> # METHOD 1: MERGE
> system.time(join1 <- merge(ldf, rdf, by = c("id1", "id2")))
user system elapsed
54.028 11.229 65.673
>
> # METHOD 2: PLYR
> # library(plyr)
> # system.time(join2 <- plyr::join(ldf, rdf, by = c("id1", "id2"), type =... 阅读全帖

o****o
发帖数: 8077

来自主题: Statistics版 - 有技巧得用R才能发挥它的威力

looks like ff package helps on solving the problem where the file is TOO
large to fit in memory, like the bigmemory package does, but it doesn't help
on efficiency here as it maps data into disk.
Am I missing anything here?
>
> library(ff)
>
> system.time(
+ dsnff<-read.csv.ffdf(file="c:\_data\MNISTtrain.csv")
+ )
user system elapsed
22.44 9.30 42.17
>
> system.time(
+ dsn1<-read.csv(file="c:\_data\MNISTtrain.csv")
+ )
user system elapsed
13.71 0.04 13.77
>
>
> t<-Sys.t... 阅读全帖

l*********g
发帖数: 975

来自主题: EB23版 - 同一个LABOR Certificate分别file EB2和EB3 140实例

用了
EB2 PERM
EB2 I140 file on PP 27/10/2010 APPROVED
EB3 I140 file on regular 24/03/2011 APPROVED on 03 Oct 2011
最后回EB2 拿绿卡
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I-140 case: Approved in 9 days (173 days less than average) (6 comments)
User: laststraw Nationality: India
Applicant Type: primary Service Center: Nebraska
Category: EB2 Priority Date: 19 Aug 2010
Application Filed: 27 Oct 2010 USCIS Received Date: 28 Oct 201... 阅读全帖

W***i
发帖数: 833

来自主题: Running版 - 没人报道芝麻啊

刚发现追踪官网芝麻实时信息需要预先注册，现在两眼一抹黑，不知道现场状况。
只有吴老师手机自动update,
At 8:14:20 am, Yan Wu (4688), 10K, Elapsed Time: 00:43:21, Pace: 06:59, Est.
Finish 10:33am (UNOFFICIAL)
At 9:02:50 am, Yan Wu (4688), HALF, Elapsed Time: 01:31:50, Pace: 07:02, Est
. Finish 10:35am (UNOFFICIAL)
At 9:41:33 am, Yan Wu (4688), 30K, Elapsed Time: 02:10:34, Pace: 07:01, Est.
Finish 10:34am (UNOFFICIAL)
好像胖哥跟马哥并肩打酱油，马哥一路跑一路照相发微博，过13迈的gun time是2:04

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

年过完了，接着练，顺带补记前几周的结果。
11/26/12
Distance: 1,750 yd
Moving Time: 40:49
Elapsed Time: 52:56
Avg Pace: 3:02 min/100 yd
Avg Moving Pace: 2:11 min/100 yd
SPL： 25.6
pull 比游的快，pull drill后游的快了，感觉有上升空间。
11/27/12
Distance: 1,950 yd
Moving Time: 48:16
Elapsed Time: 59:24
Avg Pace: 3:03 min/100 yd
Avg Moving Pace: 2:23 min/100 yd
又搞了一个好玩意-Finis Swim Tempo Pro
http://www.finisinc.com/equipment/electronics/tempo-trainer-pro
不过用起来太intense了，还得慢慢来。
开始练习flip turn. 感觉两个胳膊划水的timing有些问题，纠... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

12/10/12
Distance: 1,650 yd
Moving Time: 32:24
Elapsed Time: 52:27
Avg Pace: 3:10 min/100 yd
Avg Moving Pace: 2:05 min/100 yd
SPL: 25
12/11/12
Distance: 2,000 yd(1650 + 350)
Moving Time: 40:00
Elapsed Time: 50:16
Avg Pace: 2:31 min/100 yd
Avg Moving Pace: 2:25 min/100 yd
Best Pace: 1:51 min/100 yd
SPL: 27
12/12/12
Distance: 2,000 yd（1950+50）
Moving Time: 48:20
Elapsed Time: 48:56
Avg Pace: 2:25 min/100 yd
Avg Movin... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

过完年回来，接着练。感觉需要多花时间提高各项技术。
1/2/13
Distance: 1,650 yd（200 free, 5x100 kick, 3x100 pull, 4x100+150 free).
Moving Time: 38:29
Elapsed Time: 52:54
Avg Pace: 3:13 min/100 yd
Avg Moving Pace: 2:18 min/100 yd
Avg Kick Pace: 37.8sec/length
Avg Pull Pace: 38sec/length
Avg Swim Pace: 2:08min/100 yd
起点低，争取进步的空间也大。
1/3/13
Distance: 1,650 yd（150+50 free, 3x200 kick, 4x100 pull, 3x100+150 free).
Time: 48:07
Moving Time: 37:20
Elapsed Time: 48:07
Avg Pace: 2:00 min/100... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

总算快补上进度了。
1/14/13 时间不够，少游了一点
Distance: 650 yd（1x200yd, 2x100yd, 5x50yd)
Moving Time: 13:02
Elapsed Time: 19:54
Avg Moving Pace: 2:00 min/100 yd
Best Pace: 1:45 min/100 yd
SPL: 24
1/15/13
Distance: 2,000 yd(200yd free, 800yd kick, 600yd pull, 2x100yd free, 200
free)
Moving Time: 47:47
Elapsed Time: 53:02
Avg Pace: 2:03 min/100 yd
Best Pace: 1:46 min/100 yd
Avg Kick Pace: 37.6sec/length
Avg Pull Pace: 38.4sec/length
1/17/13
Distance: 1,000 y... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

Up to date finally.
1/23/13
Distance: 2,050 yd(500 Free, 1000yd Kick, 500Yd Pull， 50yd free)
Moving Time: 49:57
Elapsed Time: 52:40
Avg Pace: 2:03 min/100 yd
Best Pace: 1:45 min/100 yd
Avg Kick Pace: 40sec/length
Avg Pull Pace: 37.8sec/length
500yd游了10:16, 离10分钟的目标还差点。最后游了50码，49.6秒。
1/24/13
Distance: 2,050 yd（500yd free, 1000yd kick, 500yd pull, 50yd free)
Moving Time: 47:40
Elapsed Time: 50:37
Avg Pace: 2:01 min/100 yd
Best Pace: 1:29 min/100 yd
Avg Kic... 阅读全帖

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

p*****n
发帖数: 294

来自主题: Swimming版 - 自由泳学习记

大雪封山，今天偷懒罢游了。
这个星期500码和1000码都游进了2分钟的pace, 感觉小有成就。
3/4/13
Distance: 2,000 yd(1000yd free, 500yd kick, 500yd free)
忘了带表，没记分段时间，总共连歇带游45分钟。
3/5/13
Distance: 2,000 yd（2x500yd free, 500yd kick, 5x100yd free)
Moving Time: 41:07
Elapsed Time: 45:28
Avg Pace: 1:57 min/100 yd
Best Pace: 1:33 min/100 yd
两个500码用了10：07和9：52，总算进了十分钟了。
3/6/13
Distance: 2,000 yd(500yd free, 500yd kick, 450+50yd pull, 500yd free)
Moving Time: 41:46
Elapsed Time: 44:32
Avg Pace: 2:00 min/1... 阅读全帖

h**********c
发帖数: 4120

来自主题: CS版 - 请教windows下多线程程序的优化.

重新在release 下跑了一下,
// 4 threads
//Total time elapsed: 11.27700
// 8 threads
//Total time elapsed: 10.67000
//16 threads
//Total time elapsed: 10.79100
偶以前所有的程序几乎都是在debug下跑的,我还在读你的code,看如果在linux下写,有
什么能借鉴的地方.
Thanks!

slower than Release.

g********r
发帖数: 8017

来自主题: Statistics版 - 【欢迎进来讨论】for loop in R

试了一下，还真是
> a<-matrix(rnorm(10000000),ncol=100)
> dim(a)
[1] 100000 100
> r<-1:100000
> system.time(for(i in 1:100000) r[i]<-mean(a[i,]))
user system elapsed
2.239 0.053 2.276
> system.time(r2<-apply(a,1,mean))
user system elapsed
2.731 0.048 2.763
> system.time(r3<-rowMeans(a))
user system elapsed
0.033 0.001 0.034

已。

B*O
发帖数: 105

来自主题: DataSciences版 - 在R里merge两个dataframe太慢了

用match比较快。
> long =data.frame(a=seq(1,1000000), b=rnorm(10) )
> short=data.frame(a=seq(1,2000, 2), c=rnorm(10) )
> system.time(merge(x=long, y=short, all.x=T))
user system elapsed
7.253 0.071 7.385
> system.time(long$c<-rep(as.numeric(NA),dim(long)[1]))
user system elapsed
0.002 0.000 0.001
> system.time(long$c[match(short$a,long$a)]<-short$c)
user system elapsed
0.119 0.000 0.119

t****a
发帖数: 1212

来自主题: JobHunting版 - Solve sudoku in parallel

这是很有趣的问题: 如何编写并行的recusion?
我在i5 macbook pro上做了个小试验: 并行的recusion based fib函数，用FP语言(
clojure)来实现：
单thread版本:
(defn fib [n]
(if (< n 2)
n
(apply + (map fib [(dec n) (- n 2)]))))
(time (fib 32)); "Elapsed time: 1851.765 msecs"
并行版本:
(defn pfib [n m]
(if (< n 2)
n
(if (> (- m n) 4)
(apply + (map fib [(dec n) (- n 2)]))
(apply + (pmap #(pfib % m) [(dec n) (- n 2)]))
)))
(time (pfib 32 32)); "Elapsed time: 1170.566 msecs"
用clojure写并行很容易，将map改为pmap就可以了。从速度上看，提高了接近1倍... 阅读全帖

n*n
发帖数: 202

来自主题: shopping版 - [合集] 大家的电脑运行下面这段Matlab程序多长时间？ (转载)

☆─────────────────────────────────────☆
nkmelon (胖胖的西瓜) 于 (Sat Dec 16 01:08:15 2006) 提到:
发信人: nkmelon (胖胖的西瓜), 信区: PhotoGear
标题: 大家的电脑运行下面这段Matlab程序多长时间？
发信站: BBS 未名空间站 (Sat Dec 16 01:06:46 2006), 站内
===================================
clear all
close all
tic
a = randn(3000);
b = a'*a;
toc
===================================
运行版本Matlab 2006a
我的台式机
Elapsed time is 4.430484 seconds.
笔记本
Elapsed time is 20.974683 seconds.
☆─────────────────────────────────────☆
GTO (正在申请Working-In-China C

y*j
发帖数: 200

来自主题: EB23版 - EB2 NIW I140 2015有被批的吗？

一月二月的都有被批的，十二月的更多，你的应该也快了
NSC批的比较有规律，大体按RD来
TSC就是7,8,9,10每个月挑一点点应付检查，然后厚颜无耻的在网站上写上四个月的
processing time !
http://www.trackitt.com/usa-immigration-trackers/discuss/i140/2
I-140 case: Approved in 101 days (69 days less than average) (Report this
case)
User: bbeinstein Nationality: South Korea
Applicant Type: primary Service Center: Nebraska
Category: EB2-NIW Priority Date: 09 Feb 2015
Application Filed: 06 Feb 2015 USCIS Received Date: 09 Feb 2015
U... 阅读全帖

rz
发帖数: 52

来自主题: EB23版 - EB Interviews Q&A from Fragomen

重点：是根据filed 140而不是485，貌似目前版上的多数群众不一定必须被面试
Employment-Based Adjustment Interviews: What Foreign Nationals Need to Know
October 11, 2017
Executive Summary
•Employment-based adjustment of status applicants are now required to
attend a personal interview before their green card case can be processed to
completion.
•USCIS will interview applicants whose I-140 immigrant worker petition
was filed on or after March 6, 2017, as well as any family members applying
with the principal.
U.S. Ci... 阅读全帖

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未名新帖统计// 7月16日

历史上的今天