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<!DOCTYPE html>
<html>
<head>
<title>ETL on R</title>
<meta charset="utf-8">
<meta name="description" content="ETL on R">
<meta name="author" content="Cheng Yu Lin (aha) and Jia Wei Chen (jiawei)">
<meta name="generator" content="slidify" />
<meta name="apple-mobile-web-app-capable" content="yes">
<meta http-equiv="X-UA-Compatible" content="chrome=1">
<link rel="stylesheet" href="libraries/frameworks/io2012/css/default.css" media="all" >
<link rel="stylesheet" href="libraries/frameworks/io2012/css/phone.css"
media="only screen and (max-device-width: 480px)" >
<link rel="stylesheet" href="libraries/frameworks/io2012/css/slidify.css" >
<link rel="stylesheet" href="libraries/highlighters/highlight.js/css/tomorrow.css" />
<base target="_blank"> <!-- This amazingness opens all links in a new tab. --> <link rel=stylesheet href="libraries/widgets/quiz/css/demo.css"></link>
<link rel=stylesheet href="libraries/widgets/bootstrap/css/bootstrap.css"></link>
<!-- Grab CDN jQuery, fall back to local if offline -->
<script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.7.min.js"></script>
<script>window.jQuery || document.write('<script src="libraries/widgets/quiz/js/jquery.js"><\/script>')</script>
<script data-main="libraries/frameworks/io2012/js/slides"
src="libraries/frameworks/io2012/js/require-1.0.8.min.js">
</script>
</head>
<body style="opacity: 0">
<slides class="layout-widescreen">
<!-- LOGO SLIDE -->
<slide class="title-slide segue nobackground">
<hgroup class="auto-fadein">
<h1>ETL on R</h1>
<h2>非結構化資料處理</h2>
<p>Cheng Yu Lin (aha) and Jia Wei Chen (jiawei)<br/></p>
</hgroup>
<article></article>
<footer class = 'license'>
<a href='http://creativecommons.org/licenses/by-sa/3.0/'>
<img width = '80px' src = 'http://mirrors.creativecommons.org/presskit/buttons/88x31/png/by-sa.png'>
</a>
</footer>
</slide>
<!-- SLIDES -->
<slide class="" id="slide-1" style="background:;">
<article data-timings="">
<p><q> 什麼是非結構化資料？ </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-2" style="background:;">
<hgroup>
<h2>結構化資料</h2>
</hgroup>
<article data-timings="">
<p><img src = './resources/figures/structure_data.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-3" style="background:;">
<hgroup>
<h2>半結構化資料</h2>
</hgroup>
<article data-timings="">
<p><img src = './resources/figures/semi_structure_data.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-4" style="background:;">
<hgroup>
<h2>非結構化資料</h2>
</hgroup>
<article data-timings="">
<p><img src = './resources/figures/unstructure_data.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-5">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 非結構化資料可以整理出什麼訊息呢？ </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-6" style="background:;">
<article data-timings="">
<p><img src = './resources/figures/keyword_analytics.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-7" style="background:;">
<article data-timings="">
<p><img src = './resources/figures/google_flu.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-8" style="background:;">
<article data-timings="">
<p><q> 我們這場 tutorial 要帶給大家什麼呢 ? </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-9" style="background:;">
<hgroup>
<h2>web scraping</h2>
</hgroup>
<article data-timings="">
<p><img src = './resources/figures/html_pair.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-10">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><img src = './resources/figures/result1.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-11">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><img src = './resources/figures/result2.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-12" style="background:;">
<hgroup>
<h2>CH1 抓取網路資料</h2>
</hgroup>
<article data-timings="">
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-13" style="background:;">
<hgroup>
<h2>What is HTML?</h2>
</hgroup>
<article data-timings="">
<h3>一種有結構的標記資料</h3>
<p><img src = './resources/figures/html.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-14" style="background:;">
<article data-timings="">
<p><img src = './resources/figures/html_pair.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-15">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 其實它們是有結構的 </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-16" style="background:;">
<hgroup>
<h2>Document Object Model (DOM)</h2>
</hgroup>
<article data-timings="">
<h3>html 呈現樹狀結構</h3>
<p><img src = './resources/figures/dom.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-17" style="background:;">
<hgroup>
<h2>樹狀結構的內容</h2>
</hgroup>
<article data-timings="">
<ol>
<li>nodename</li>
<li>attribute</li>
<li>text</li>
</ol>
<pre><code class="r"><a href = "www.meetup.com/Taiwan-R">
Taiwan R User Group Website
</a>
</code></pre>
<pre><code class="r">nodename : a
attribute : href with value "www.meetup.com/Taiwan-R"
text: "Taiwan R User Group Website"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-18" style="background:;">
<hgroup>
<h2>xpath 常用到的操作</h2>
</hgroup>
<article data-timings="">
<ul>
<li><p>/ finds the root node</p></li>
<li><p>// selects from anywhere in the tree</p></li>
<li><p>'.' selects current node</p></li>
<li><p>'..' selects parent of current node</p></li>
<li><p>@ selects attributes</p></li>
</ul>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-19" style="background:;">
<hgroup>
<h2>如果想抓 a 的話</h2>
</hgroup>
<article data-timings="">
<h3>we can use:</h3>
<pre><code class="r">"/../body/div/a" or "//a"
</code></pre>
<p><img src = './resources/figures/dom.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-20" style="background:;">
<hgroup>
<h2>如果指定 a 的 attribute 或 text</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">If we had '<a href = "www.meetup.com/Taiwan-R">Taiwan R User Group Website</a>'
</code></pre>
<p>抓出 href = ’www.meetup.com/Taiwan-R’ 的 a</p>
<pre><code class="r">"//a[@href = ’www.meetup.com/Taiwan-R’]"
</code></pre>
<p>抓出 text = ’Taiwan R User Group Website’ 的 a</p>
<pre><code class="r">"//a[text() = ’Taiwan R User Group Website’]"
</code></pre>
<pre><code class="r">nodename : a
attribute : href with value "www.meetup.com/Taiwan-R"
text: "Taiwan R User Group Website"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-21" style="background:;">
<hgroup>
<h2>匯入套件</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">require(DSC2014Tutorial)
require(XML)
require(stringr)
require(xts)
require(reshape2)
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-22" style="background:;">
<hgroup>
<h2>開啟下載好的 html 檔案</h2>
</hgroup>
<article data-timings="">
<h3><a href="https://tw.news.yahoo.com/real-estate/archive/1.html">資料來源 - yahoo 新聞</a></h3>
<pre><code class="r"># 讀取 ETL 相關檔案所在的路徑
path <- ETL_file('')
docs <- grep("*.html",dir(path), value = TRUE)
</code></pre>
<pre><code class="r">pages <- sapply(docs, function(d){
path <- ETL_file(d)
f <- file(path, encoding = 'UTF-8')
f_size <- file.info(ETL_file(d))$size
content <- readChar(f, f_size)
close(f)
return(content)
})
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-23" style="background:;">
<hgroup>
<h2>抓出 title和 連結</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">library(XML)
# 建立 DOM Tree
doc <- htmlTreeParse(pages[1], useInternalNodes = TRUE)
# 抓出 node a 的 attr
attr <- xpathApply(doc, "//ul/li/div/div/h4/a", xmlAttrs)
# 抓出 node a 的 text
text <- xpathSApply(doc, "//ul/li/div/div/h4/a", xmlValue)
</code></pre>
<h3>text 結果</h3>
<pre><code>## [1] "稅制改革座談 財長明督軍"
## [2] "缺地… 租稅引導產業南移"
## [3] "房地合一 建商：重稅擾民"
## [4] "租不起 「天天見麵」悄收台北店"
## [5] "《世紀專欄》地價稅納稅義務基準日為每年8月31日"
## [6] "苗房屋標準單價公告調整 7月起實施"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-24" style="background:;">
<article data-timings="">
<p><img src = './resources/figures/xpath_title.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-25" style="background:;">
<hgroup>
<h2>一次抓多篇</h2>
</hgroup>
<article data-timings="">
<pre><code class="r"># lapply : 最後將回傳 list 型態的結果
title <- lapply(pages, function(p){
doc <- htmlTreeParse(p, useInternalNodes = TRUE)
xpathSApply(doc, "//ul/li/div/div/h4/a", xmlValue)
})
</code></pre>
<pre><code>## [[1]]
## [1] "稅制改革座談 財長明督軍" "缺地… 租稅引導產業南移"
##
## [[2]]
## [1] "抗議一地兩價 遷建戶下跪向費鴻泰陳情"
## [2] "房產觀望氣氛 中市推案減兩成"
##
## [[3]]
## [1] "綠大地五股市區 千坪綠地" "在地專家"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-26" style="background:;">
<hgroup>
<h2>練習題1</h2>
</hgroup>
<article data-timings="">
<h3>請填入適當的 xpath 抓出新聞來源, 日期, 時間</h3>
<pre><code class="r">src_list <- xpathSApply(doc, ___ , xmlValue)
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-27" style="background:;">
<article data-timings="">
<p><img src = './resources/figures/xpath_time.png' ></img></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-28" style="background:;">
<hgroup>
<h2>解答1</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">src_list <- xpathSApply(doc, "//cite", xmlValue)
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-29" style="background:;">
<hgroup>
<h2>(自行操作) 保存/讀取 抓下來的數據</h2>
</hgroup>
<article data-timings="">
<h3>先將結果合併為表格</h3>
<pre><code class="r">doc <- do.call(rbind, title)
</code></pre>
<h3>寫入 / 讀回 數據</h3>
<pre><code class="r">writeLines(doc, "news_yahoo.txt")
news_yahoo <- readLines('news_yahoo.txt')
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-30" style="background:;">
<hgroup>
<h2>匯入這次用的資料</h2>
</hgroup>
<article data-timings="">
<h3><a href="http://house.cnyes.com/News/tw_housenews/List.htm">資料來源 - 鉅亨網</a></h3>
<pre><code class="r">path <- ETL_file('news.txt')
f <- file(path, encoding="UTF-8")
house_news <- readLines(f)
head(house_news)
</code></pre>
<pre><code>## [1] "2014-06-24富邦人壽信義區再插旗 A25案172億元奪標"
## [2] "2014-06-24北市A25地上權案 富邦權利金172.88億元得標"
## [3] "2014-06-23房市管制 央行將化明為暗"
## [4] "2014-06-20史上頭一遭!大直新地王 1坪212萬＃超越信義之星直逼帝寶 中山新天價"
## [5] "2014-06-20大直帝景水花園實價首破200萬 北市3大豪宅板塊確立"
## [6] "2014-06-19樺福千金捷運宅標脫率89.4% 均價63萬元屬合理範圍"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-31" style="background:;">
<hgroup>
<h2>CH2 字串處理</h2>
</hgroup>
<article data-timings="">
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-32" style="background:;">
<hgroup>
<h2>正規表達 介紹</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">\\d -> 數字
\\w -> 單字
. -> 任意字元(數字, 單字, 標點符號 ..)
? -> 出現 0或1 次
+ -> 出現 1次 以上
* -> 出現 0次 以上
^ -> 出現在行首
$ -> 出現在行尾
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-33" style="background:;">
<article data-timings="">
<pre><code class="r">x <- c("apples*14", "flour", "sugar*100", "milk*3")
</code></pre>
<h3>批配2個數字</h3>
<pre><code class="r">str_extract(x, "\\d{2}")
</code></pre>
<pre><code>## [1] "14" NA "10" NA
</code></pre>
<h3>批配2~3個數字</h3>
<pre><code class="r">str_extract(x, "\\d{2,3}")
</code></pre>
<pre><code>## [1] "14" NA "100" NA
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-34" style="background:;">
<article data-timings="">
<pre><code class="r">x <- c("apples*14", "flour", "sugar*100", "milk*3")
</code></pre>
<h3>批配出現一次以上的a或p</h3>
<pre><code class="r">str_extract(x, "[ap]+")
</code></pre>
<pre><code>## [1] "app" NA "a" NA
</code></pre>
<h3>也可以搭配{m,n}</h3>
<pre><code class="r">str_extract(x, "[ap]{1,4}")
</code></pre>
<pre><code>## [1] "app" NA "a" NA
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-35" style="background:;">
<hgroup>
<h2>練習題2</h2>
</hgroup>
<article data-timings="">
<h3>猜猜看這會批配出什麼東西？</h3>
<pre><code class="r">x <- c("apples*14", "flour", "allen", "aside")
str_extract(x, "a[elpn]+.?")
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-36" style="background:;">
<hgroup>
<h2>解答2</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">x <- c("apples*14", "flour", "allen", "aside")
str_extract(x, "a[elpn]+.?")
</code></pre>
<pre><code>## [1] "apples" NA "allen" NA
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-37" style="background:;">
<hgroup>
<h2>進階一點的正規表達</h2>
</hgroup>
<article data-timings="">
<h3>抽取 log訊息時很有用的 () 批配</h3>
<h3>可以把 match 的字儲存倒 \{n}</h3>
<pre><code class="r">x <-"2014-06-24富邦人壽信義區再插旗 A25案172億元奪標"
patten <- "(\\d{4}-\\d{2}-\\d{2}).+(信義.?).+"
gsub(patten, "\\1, \\2", x)
</code></pre>
<pre><code>## [1] "2014-06-24, 信義區"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-38" style="background:;">
<hgroup>
<h2>練習題3</h2>
</hgroup>
<article data-timings="">
<p>請利用下面提示，填入適當的 Patten，產生出下面結果</p>
<pre><code class="r"># 請利用 \\d{?}-\\d{?}-\\d{?} 抽取出時間
dates <- str_extract(house_news, ___)
# 請利用 \\d{?}-\\d{?}-\\d{?} 把時間取代為 ''
titles <- str_replace(house_news, ___, ___)
house_news <- cbind(dates, titles)
</code></pre>
<pre><code>## dates titles
## [1,] "2014-06-24" "富邦人壽信義區再插旗 A25案172億元奪標"
## [2,] "2014-06-24" "北市A25地上權案 富邦權利金172.88億元得標"
## [3,] "2014-06-23" "房市管制 央行將化明為暗"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-39" style="background:;">
<hgroup>
<h2>解答3</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">dates <- str_extract(house_news, "\\d{4}-\\d{2}-\\d{2}")
titles <- str_replace(house_news, "\\d{4}-\\d{2}-\\d{2}", "")
house_news <- cbind(dates, titles)
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-40" style="background:;">
<hgroup>
<h2>清除符號的方法介紹</h2>
</hgroup>
<article data-timings="">
<h3>[[:punct:]] 表示標點符號</h3>
<h3>[[:blank:]] 表示分隔符號</h3>
<pre><code class="r">str_replace_all("i l<ik>e ?R pr:ogr,a%mi!ng", "[[:punct:]]", "")
</code></pre>
<pre><code>## [1] "i like R programing"
</code></pre>
<pre><code class="r">str_replace_all("a \t p \t p ", "[[:blank:]]", "")
</code></pre>
<pre><code>## [1] "app"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-41" style="background:;">
<hgroup>
<h2>如果想清除中文特殊符號 ...</h2>
</hgroup>
<article data-timings="">
<h3>這是 utf-8 編碼</h3>
<pre><code class="r">punctuation <- "\u3002 \uff1b \uff0c \uff1a \u201c \u201d \uff08 \uff09 \u3001 \uff1f \u300a \u300b"
punctuation
</code></pre>
<pre><code>## [1] "。 ； ， ： “ ” （ ） 、 ？ 《 》"
</code></pre>
<pre><code class="r">str_replace_all("。 ； ， ： “ ” （ ） 、 ？ 《 》", punctuation, "")
</code></pre>
<pre><code>## [1] ""
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-42">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 再來要介紹一個非常重要的 function </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-43" style="background:;">
<hgroup>
<h2>substr 用法</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">substr('富邦人壽信義區再插旗 A25案172億元奪標', 1, 4)
</code></pre>
<pre><code>## [1] "富邦人壽"
</code></pre>
<pre><code class="r">substr('富邦人壽信義區再插旗 A25案172億元奪標', 5, 7)
</code></pre>
<pre><code>## [1] "信義區"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-44">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q>看來很簡單,那為什麼說它很重要呢？</q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-45">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 做個練習可能就有感覺了 </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-46" style="background:;">
<hgroup>
<h2>練習題4</h2>
</hgroup>
<article data-timings="">
<h3>空格填 i or i+1，才呈現出下面使用範例？</h3>
<pre><code class="r">ngram <- function(sentence, n){
chunk <- c()
for(i in 1 : (nchar(sentence)-n+1)){
chunk <- append(chunk, substr(sentence, ___ , i+n-1))
}
return(chunk)
}
</code></pre>
<h3>使用範例</h3>
<pre><code class="r">ngram('富邦人壽信義區再插旗', 2)
</code></pre>
<pre><code>## [1] "富邦" "邦人" "人壽" "壽信" "信義" "義區" "區再" "再插" "插旗"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-47" style="background:;">
<hgroup>
<h2>解答4</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">ngram <- function(sentence, n){
chunk <- c()
for(i in 1 : (nchar(sentence)-n+1)){
chunk <- append(chunk, substr(sentence, i, i+n-1))
}
return(chunk)
}
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-48" style="background:;">
<article data-timings="">
<pre><code class="r">sapply(titles, ngram, 2, USE.NAMES = FALSE)[1:3]
</code></pre>
<pre><code>## [[1]]
## [1] "富邦" "邦人" "人壽" "壽信" "信義" "義區" "區再" "再插" "插旗" "旗 "
## [11] " A" "A2" "25" "5案" "案1" "17" "72" "2億" "億元" "元奪"
## [21] "奪標"
##
## [[2]]
## [1] "北市" "市A" "A2" "25" "5地" "地上" "上權" "權案" "案 " " 富"
## [11] "富邦" "邦權" "權利" "利金" "金1" "17" "72" "2." ".8" "88"
## [21] "8億" "億元" "元得" "得標"
##
## [[3]]
## [1] "房市" "市管" "管制" "制 " " 央" "央行" "行將" "將化" "化明" "明為"
## [11] "為暗"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-49" style="background:;">
<article data-timings="">
<pre><code class="r">sapply(titles, ngram, 3, USE.NAMES = FALSE)[1:3]
</code></pre>
<pre><code>## [[1]]
## [1] "富邦人" "邦人壽" "人壽信" "壽信義" "信義區" "義區再" "區再插"
## [8] "再插旗" "插旗 " "旗 A" " A2" "A25" "25案" "5案1"
## [15] "案17" "172" "72億" "2億元" "億元奪" "元奪標"
##
## [[2]]
## [1] "北市A" "市A2" "A25" "25地" "5地上" "地上權" "上權案"
## [8] "權案 " "案 富" " 富邦" "富邦權" "邦權利" "權利金" "利金1"
## [15] "金17" "172" "72." "2.8" ".88" "88億" "8億元"
## [22] "億元得" "元得標"
##
## [[3]]
## [1] "房市管" "市管制" "管制 " "制 央" " 央行" "央行將" "行將化"
## [8] "將化明" "化明為" "明為暗"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-50">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 透過substr才能從文章裡抽出詞彙呀！ </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-51" style="background:;">
<hgroup>
<h2>把字段長度1~6都列舉出來，並分別儲存</h2>
</hgroup>
<article data-timings="">
<pre><code class="r">titles <- gsub("\\s", "", titles)
piece <- list()
piece[['1']] <- unlist(sapply(titles, ngram, 1, USE.NAMES = FALSE))
piece[['2']] <- unlist(sapply(titles, ngram, 2, USE.NAMES = FALSE))
piece[['3']] <- unlist(sapply(titles, ngram, 3, USE.NAMES = FALSE))
piece[['4']] <- unlist(sapply(titles, ngram, 4, USE.NAMES = FALSE))
piece[['5']] <- unlist(sapply(titles, ngram, 5, USE.NAMES = FALSE))
piece[['6']] <- unlist(sapply(titles, ngram, 6, USE.NAMES = FALSE))
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-52">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 但是有個問題 ！ </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-53" style="background:;">
<article data-timings="">
<pre><code class="r">sapply(titles, ngram, 3, USE.NAMES = FALSE)[1:3]
</code></pre>
<pre><code>## [[1]]
## [1] "富邦人" "邦人壽" "人壽信" "壽信義" "信義區" "義區再" "區再插"
## [8] "再插旗" "插旗A" "旗A2" "A25" "25案" "5案1" "案17"
## [15] "172" "72億" "2億元" "億元奪" "元奪標"
##
## [[2]]
## [1] "北市A" "市A2" "A25" "25地" "5地上" "地上權" "上權案"
## [8] "權案富" "案富邦" "富邦權" "邦權利" "權利金" "利金1" "金17"
## [15] "172" "72." "2.8" ".88" "88億" "8億元" "億元得"
## [22] "元得標"
##
## [[3]]
## [1] "房市管" "市管制" "管制央" "制央行" "央行將" "行將化" "將化明" "化明為"
## [9] "明為暗"
</code></pre>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-54">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q>注意到了嗎？</q>
<q>裡面有很多沒意義的字串</q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-55">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q>如何解決呢？</q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-56">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> '房價偏' 是不是一個有意義的詞彙呢？ </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-57">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> '房價' + '偏' 是否機率獨立？</q></p>
<p><q> '房' + '價偏' 是否機率獨立？</q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-58">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 服貿協議 </q></p>
<p><q> '服貿協' 右邊幾乎只能接 '議'</q></p>
<p><q> '貿協議' 左邊幾乎只能接 '服'</q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-59">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 利用這兩種性質來篩選掉沒意義的字串 </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-60">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>
<p><q> 但是程式該怎麼寫呢？ </q></p>
</article>
<!-- Presenter Notes -->
</slide>
<slide class="" id="slide-61">
<hgroup>
</hgroup>
<article class = 'flexbox vcenter'>