Turn your R code into packages that others can easily download and use. This practical book shows you how to bundle reusable R functions, sample data, and documentation together by applying the package development philosophy used in the package known as the tidyverse (and beyond). In the process, you'll work with devtools, usethis, roxygen2, and testthat, a set of R packages th...(展开全部)

Turn your R code into packages that others can easily download and use. This practical book shows you how to bundle reusable R functions, sample data, and documentation together by applying the package development philosophy used in the package known as the tidyverse (and beyond). In the process, you'll work with devtools, usethis, roxygen2, and testthat, a set of R packages th...(展开全部)

简介：（修改中）坏心情，快消失。

简介：自设abo，正负cp都是he开学可能周六日双更中考完连更

New-for-this-edition features include 'First Time' for visitors who haven't been to England before, museum itineraries to help readers get to the heart of attractions like the British Museum, and driving routes around the Cotswolds;The maps in the London chapter will be in full-colour to help readers better navigate the country's capital.

对于每个到访者来说，巴黎标志性的建筑、精致的美食、时髦的精品店和无价的艺术珍品，都具有一种超越时空的亲切感——初次见面却毫不陌生的埃菲尔铁塔的铁制尖顶、雄伟凯旋门守卫着的巴黎最迷人的大街、塞纳河上灯火辉煌的桥梁，还有雷诺阿、罗丹、毕加索、莫奈、马奈、达利和梵高这些伟大的名字。这里毫无疑问是全世界最重要的一座大都市，而奇妙的是身处当地的你可以感受到真实的社区生活，去探索精巧的商店、市场、咖啡馆、隐蔽的公园，也许换一个角度，你就打开了另一个巴黎。

蜿蜒的河流腾起薄雾，林立的峰丛远近浓淡，前景的纵横阡陌间，几个墨点勾出农夫与耕牛。细雨中漫步在黄姚古镇闪亮的石板路，唯有时间能在此刻下印记；站在乐业大石围天坑边上倒吸一口冷气，感叹你的小和它的大是如此不成比例；三江工艺精湛的鼓楼和风雨桥堪称巧夺天工，你可以在它雄伟的身姿下感受护佑，而涠洲岛上狂放肆意的海蚀地貌绝对是写意，潮起潮落就是你和它的对话时间。行走在广西的天地间，很容易发现中国诗画的灵感源头。总有一瞬间，你会与那些曾经听过的、读过的或是梦见过的山水画卷不期而遇。

Basking by the Mediterranean, Barcelona is the cosmopolitan party city that just never stops. Be dazzled by Gaudi masterpieces, stroll down La Rambla, dance the night away in a hip discoteca, delight in Catalan fare, sample cava in a traditional bodega or catch the sun by the sea - discover every side of the city with this smart and stylish guide. • GET THE INSIDE SCOOP fro...(展开全部)