buiding the toolchain from iphone-dev

October 22, 2010 Leave a comment

没有Mac有个iphone,想玩app怎么办?据说是可以在linux或者windows(cygwin)上做开发的,O’Reilly还出了本书iPhone Open Application Development。在有钱买apple前,实在忍不住想在最cool的移动计算平台iPhone上玩玩它的应用开发(好像在《程序员》里对Android创始人的专访中提到,Andy Rubin用的手机是iPhone)。

大概记录一下在ubuntu910下构建toolchain的步骤,主要步骤参考官网wiki的HOWTO build the toolchain。flex (2.5.35)和bison (2.4.1)都是直接从ubuntu的源里安装的。由于默认的gcc是4.4版本,在编译llvm时出现一堆”xxx was not declared in this scope”的问题,参考issue 149直接换gcc-4.1顺利编译通过。然后构建odcctools时出现了”configure.ac:12: error: possibly undefined macro: AM_PROG_LEX”问题,然后按照issue 98的方法解决。

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Categories: development

some links about statistical tools

October 15, 2010 1 comment

The reason i explore the statistical tools is related to my research project. Our lab has a project about applying sensor networks to agriculture. To help agronomists have better understanding about their plants, we employ sensor networks to collect environmental parameters of crops grown in green houses and crop fields.  Although we got a great amount of data, the data is not ready for use. We have to preprocess the raw data to eliminate or correct the false ones, which usually requires statistical computation over the datasets. After simple survey, I’ve decided to give R a little try.

Relevant Links

1. Comparison of data analysis packages: R, Matlab, SciPy, Excel, SAS, SPSS, Stata

A brief comparison  about data analysis packages. There are also lots of valuable comments along with the article.

2. Why are SAS/STATA the default statistical tools for undergrads? Why not teach R?
The thread on reddit.com talked about SAS and R.

3. Intro to Statistics – MATLAB Style

A short introduction to statistical toolbox in Matlab. Also, there are several posts on the same topic in the scope of Matlab.

4. Trilogy of Statistical programming with R on IBM developerworks

Categories: research

startup, have you considered it?

September 19, 2010 Leave a comment
"So who should start a startup? Someone who is a good hacker, between
about 23 and 38, and who wants to solve the money problem in one
shot instead of getting paid gradually over a conventional working
life.

I can’t say precisely what a good hacker is. At a first rate
university this might include the top half of computer science
majors. Though of course you don’t have to be a CS major to be a
hacker; I was a philosophy major in college.

It’s hard to tell whether you’re a good hacker, especially when
you’re young. Fortunately the process of starting startups tends
to select them automatically. What drives people to start startups
is (or should be) looking at existing technology and thinking, don’t
these guys realize they should be doing x, y, and z? And that’s
also a sign that one is a good hacker."

I really like the text excerpted from the big (or god father ) Paul Graham’s How to Start a Startup? , though I haven’t read the whole article yet.

Categories: 其它

地产商是不是疯了

September 18, 2010 Leave a comment
最近手机平均每天收到10条商品房广告,烦死了……也不能退订,因私严重被侵犯

是不是开发商买不出去房子着急了?

Categories: 日常生活

超声驱蚊是否靠谱?

September 3, 2010 3 comments

家里总是时不时的溜进蚊子,而且老咬的是我(我B型血),很郁闷。不知道是居住环境还是气候的因素,在瑞士的时候好像基本没见到过苍蝇和蚊子之类的东东,倒是有很多蜘蛛,长腿的,大个的……

之前在世纪金花超市见到有康居宝卖超声驱蚊的,价格接近百元,这对我这种迷信电子玩意而又深受蚊子其害的人来说急剧吸引力。今天先是淘宝,发现超声驱蚊器价格从十几元到百元的都有,从原理上说超声驱蚊的成本很低,所以十几元和几百元的产品差别应该不是大,要差也是细节和一些工艺上。本来是想过几天卖的,但突然想了解一下功效,于是搜索。结果比较让人失望,大部分人说买回去让人失望,在amazon上看到15个差评5个好评(怀疑是托儿)。另外英国Channel 4,在2007年4月份发表的一份报道声称通过10实验(样本有点少……)表明超声驱蚊没有作用。同样,MedicineNet.com上关于驱蚊的专题说某组织通过多方的引用表明此类设备没有效果。最后,在美国蚊虫控制协会(AMCA)的官方网站mosquito.org的常见问题中,他们对超声驱蚊的功效予以了否定。认为所谓的高科技,对人无害的超声驱蚊是驱蚊器制造商一种夸大的市场行为。实验证明,无聊是固定频段还是宽频段的任何方向的超声波都无法去除蚊虫。

最后,来自国内的报道,在《大连医科学报》1995年04期中,《近超声波驱蚊器驱蚊效果的实验观察》的论文也证实了超声驱蚊器对“各型驱蚊器对蚊虫驱赶效果不明显,对雌蚊吸血活动无影响。”

好了,我的结论是,所谓的超声驱蚊器应该退出市场。我还是比较相信AMCA这种致力于疾病蚊虫控制的非营利组织的言论的。

结论:

  1. 所谓的高科技有时候是用来骗钱的
  2. 中国互联网上有用且易于被公众访问信息实在是太少
  3. 中国的NPO太少
Categories: 科技与互联网

手机历险记

August 23, 2010 9 comments
上礼拜回家,坐公车人特别多,刚一下车发觉手机不见了。于是我赶忙叫住司机说自己手机丢了,要求用打一个电话,站在车门口的两个伙计说人已经跑了,让我下车追。但我的直觉告诉我,小偷应该是从我身后下手,还在车上,还是强烈要求打一个的电话确认一下。然后司机便让我先上车,让我在车上找,他继续开车(wtf,司机应该停下来协助一下,我现在很怀疑司机和小偷是一伙的),我是想如果小偷真的走了,追是没戏。其实当时觉得应该手机是找不回来了,但我还是不死心,要是小偷在车上,还是有一线希望,于是决定先上车。结果门没有关好,司机没有启动,然后又把车停下来,开了车门。这时候突然听到有人说,看到手机从车上被扔了出来。一开始我不太相信,后来很多人都这么说,于是我下了车,在站台上等车的几个学生帮我找到了手机。据说他们看到是在车门口的那个人扔下来的。

今天突然在想要是有lie to me中cal的洞察力,我当时就应该可以看穿那个说谎贼了。但是,接下来是什么情况就不得而知了,和一帮小偷的正面对峙,路人漠然围观,然后受伤……

想起这个月初同学聚会时,疯子说怎么感觉赚的钱不少,还是不够花,日子还是蛮苦的。我在想也许这根本不是钱多少的问题,应该是这个不靠谱的社会让人们缺乏足够安全感的问题。买得起房子就有安全感了吗?如果那房子是不合格的伪楼,开发商最后携款潜逃,你的投资就打了水漂。如果那房子交付后一堆的问题,开发商物业迟迟不给解决,让你觉得有房还不如没房。开得起车子有怎么样,想着马路上那么多不通过驾照考试就取得驾驶证的司机,开车也许并不比做公车好到哪里去。

所有的投资都让人觉得不靠谱,因此,有再多的钱也是白搭。存着怕以后通胀,花了怕未来没保障,花出去的钱如果眼神不好,基本别想要回来……

Categories: 日常生活

交警手势信号

August 19, 2010 2 comments

教材上的有些诡异,还是看公安部官方网站公布的的图示靠谱。

Categories: 其它