How to Sample a specific proportion of lines from a big file in r?

如何从R中的大文件的特定比例的线样？

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Steaming time can only be a layer of steam, how to sample can be steamed more food regimen?

蒸的时刻每次只能蒸一层，如何样才可以蒸的更多饮食养生？

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Follow these instructions to see how to sample data in an Oracle database (Note: This applies to other database vendors as well).

按照以下步骤查看Oracle数据库中的数据(注意：这些步骤也适用于其他数据库)。

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Somebody told me, by the way, that the sample concept sheet that we have listed on the website couldn't be downloaded, so we'll fix that, but we'll also send you out by email a sample concept sheet, along with guidelines for how to prepare them.

有人告诉我,顺便说下,网站上所列的观点报告范例不能下载,我们会进行修复的,同时我们也会通过电子邮件将范例报告,以及备写指南一并发给你们

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

This is very important,which is why I am doing it: "If we want to know how fast a human being can run, then it is no use to average out the speed of a "good sample" of the population; it is far better to collect Olympic gold medal winners and see how well they can do.

这话非常重要，是我作这个研究的原因：,“如果想知道人类最快能跑多快，那从好的样本中测出平均数是“,没用的;,而应该收集田径类奥运冠军的信息,看他们能跑多快。

哈佛公开课 - 幸福课课程节选

Also, each year the network likes to point out and I'm sure the email is coming soon how viewers tend to sample new shiny shows at the start of the fall, then eventually return to reliable 'ol CBS. We'll see if that holds true this season too.

CNN: 'Revolution' crushes 'Hawaii,' 'Dancing' ratings dive

This brief moment is all the time that the sensors inside will have to measure how the sample's electrical resistance changes, so Dr Brooks and his team have their work cut out to get good data.

ECONOMIST: Magnetism

This allowed us to create sample scenarios to showcase ingenuity and innovation, including how the mobile app can alert individuals on its location and areas to avoid for a fire, flood or terrorist attack, all by aggregating emergency frequency broadcast and GPS technology.

FORBES: Move up http://i.forbesimg.com t Move down