輕鬆學習 R 語言：基礎資料框處理
By: Yao-Jen Kuo
Tags: Data Science, R, Programming, Dataframes, R Programming

資料框的維度與外觀

以 read.csv() 函數讀入一個副檔名為 .csv 的文字檔案，它記錄了 1995 至 1996 年球季的美國職籃（NBA）芝加哥公牛隊球員名單與一些球員基本資訊。接著可以使用 nrow() 、 ncol() 與 dim() 這三個內建函數可以幫助我們暸解所輸入資料框的列數、欄數與維度資訊。其中 nrow() 函數命名是 number of rows 的縮寫， ncol() 函數命名是 number of columns 的縮寫， dim() 函數命名是 dimensions 的縮寫，知道這些函數的全稱，可以有效幫助我們記憶它們。



## > chicago_bulls <- read.csv(csv_url)

## > nrow(chicago_bulls)

## [1] 15

## > ncol(chicago_bulls)

## [1] 7

## > dim(chicago_bulls)

## [1] 15 7 ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls nrow(chicago_bulls)## [1] 15## > ncol(chicago_bulls)## [1] 7## > dim(chicago_bulls)## [1] 15 7

使用 View() 函數可以將整個資料框以美觀的樣式顯示在程式碼（Script）區塊。

使用 View() 函數可以將整個資料框以美觀的樣式顯示

在面對觀測值眾多的資料框我們不會呼叫 View() 函數，因為那將耗時且耗費較多電腦資源，這時會改使用 head() 與 tail() 這兩個函數可以得知部分資料框的外觀，顯示在終端機（Console）區塊，預設印出前六列或後六列觀測值（含變數名稱。）



## > chicago_bulls <- read.csv(csv_url)

## > head(chicago_bulls)

## No. Player Pos Ht Wt Birth.Date College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## > tail(chicago_bulls)

## No. Player Pos Ht Wt Birth.Date College

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls head(chicago_bulls)## No. Player Pos Ht Wt Birth.Date College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## > tail(chicago_bulls)## No. Player Pos Ht Wt Birth.Date College## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University

使用 colnames() 函數可以得知資料框的變數名稱、使用 row.names() 可以得知資料框的列索引值。

資料框的詳細資訊

使用 summary() 函數可以得知每一個變數的描述性統計量。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > summary(chicago_bulls)

## No. Player Pos Ht Wt Birth.Date

## Min. : 0.00 Length:15 Length:15 Length:15 Min. :175.0 Length:15

## 1st Qu.:11.00 Class :character Class :character Class :character 1st Qu.:193.5 Class :character

## Median :25.00 Mode :character Mode :character Mode :character Median :220.0 Mode :character

## Mean :29.13 Mean :219.0

## 3rd Qu.:34.50 3rd Qu.:242.5

## Max. :91.00 Max. :265.0

## College

## Length:15

## Class :character

## Mode :character ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls summary(chicago_bulls)## No. Player Pos Ht Wt Birth.Date## Min. : 0.00 Length:15 Length:15 Length:15 Min. :175.0 Length:15## 1st Qu.:11.00 Class :character Class :character Class :character 1st Qu.:193.5 Class :character## Median :25.00 Mode :character Mode :character Mode :character Median :220.0 Mode :character## Mean :29.13 Mean :219.0## 3rd Qu.:34.50 3rd Qu.:242.5## Max. :91.00 Max. :265.0## College## Length:15## Class :character## Mode :character

使用 str() 函數可以得知資料框複合式的資訊，包含像是資料結構的種類、觀測值數、變數個數、變數名稱與前幾筆觀測值等， str() 函數的命名是 structure 的縮寫。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > str(chicago_bulls)

## 'data.frame': 15 obs. of 7 variables:

## $ No. : int 0 30 35 53 54 9 23 25 7 13 ...

## $ Player : chr "Randy Brown" "Jud Buechler" "Jason Caffey" "James Edwards" ...

## $ Pos : chr "PG" "SF" "PF" "C" ...

## $ Ht : chr "6-2" "6-6" "6-8" "7-0" ...

## $ Wt : int 190 220 255 225 240 185 195 175 192 265 ...

## $ Birth.Date: chr "May 22, 1968" "June 19, 1968" "June 12, 1973" "November 22, 1955" ...

## $ College : chr "University of Houston, New Mexico State University" "University of Arizona" "University of Alabama" "University of Washington" ... ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls str(chicago_bulls)## 'data.frame': 15 obs. of 7 variables:## $ No. : int 0 30 35 53 54 9 23 25 7 13 ...## $ Player : chr "Randy Brown" "Jud Buechler" "Jason Caffey" "James Edwards" ...## $ Pos : chr "PG" "SF" "PF" "C" ...## $ Ht : chr "6-2" "6-6" "6-8" "7-0" ...## $ Wt : int 190 220 255 225 240 185 195 175 192 265 ...## $ Birth.Date: chr "May 22, 1968" "June 19, 1968" "June 12, 1973" "November 22, 1955" ...## $ College : chr "University of Houston, New Mexico State University" "University of Arizona" "University of Alabama" "University of Washington" ...

解構資料框

一個資料框可以被解構為長度為 1 的向量、長度大於 1 的向量與較小的資料框（subset），在輕鬆學習 R 語言：資料結構中已經有初步的認識，但為了內容的完整性，讓我們再複習一下相關的技巧。首先是透過 [m, n] 可以從資料框中將位於第 m 列、第 n 欄的資料取出，成為長度為 1 的向量。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > mj <- chicago_bulls[7, "Player"]

## > mj

## [1] "Michael Jordan" ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls mj mj## [1] "Michael Jordan"

透過 [, n] 可以從資料框中將位於第 n 欄的資料取出，成為長度為 m 的向量。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > players <- chicago_bulls[, "Player"]

## > players

## [1] "Randy Brown" "Jud Buechler" "Jason Caffey" "James Edwards" "Jack Haley" "Ron Harper"

## [7] "Michael Jordan" "Steve Kerr" "Toni Kukoc" "Luc Longley" "Scottie Pippen" "Dennis Rodman"

## [13] "John Salley" "Dickey Simpkins" "Bill Wennington" ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls players players## [1] "Randy Brown" "Jud Buechler" "Jason Caffey" "James Edwards" "Jack Haley" "Ron Harper"## [7] "Michael Jordan" "Steve Kerr" "Toni Kukoc" "Luc Longley" "Scottie Pippen" "Dennis Rodman"## [13] "John Salley" "Dickey Simpkins" "Bill Wennington"

透過 [m, ] 可以從資料框中將位於第 m 列的資料取出，成為外觀為 1xn 的較小資料框。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > trio <- chicago_bulls[c(7, 11, 12), ]

## > trio

## No. Player Pos Ht Wt Birth.Date College

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls trio trio## No. Player Pos Ht Wt Birth.Date College## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

除了透過 [m, ] 能夠將原始資料框解構為較小資料框，也能夠使用判斷條件產生邏輯值向量選擇部分的資料框，也是實務上較常使用的方式。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > the_trio <- chicago_bulls$Player %in% c("Michael Jordan", "Scottie Pippen", "Dennis Rodman")

## > the_trio

## [1] FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE

## > trio <- chicago_bulls[the_trio, ]

## > trio

## No. Player Pos Ht Wt Birth.Date College

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls the_trio the_trio## [1] FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE## > trio trio## No. Player Pos Ht Wt Birth.Date College## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

假如希望融入更多的判斷條件，可以使用 & （and）或者 | （or）運算子將邏輯值向量交集或者聯集。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > # 聯集

## > logical_union <- chicago_bulls$Player == "Michael Jordan" | chicago_bulls$Player == "Scottie Pippen" | chicago_bulls$Player == "Dennis Rodman"

## > logical_union

## [1] FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE

## > trio <- chicago_bulls[logical_union, ]

## > trio

## No. Player Pos Ht Wt Birth.Date College

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## > # 交集

## > logical_intersection <- chicago_bulls$Pos != "PG" & chicago_bulls$Player != "Toni Kukoc" & chicago_bulls$Wt <= 210

## > logical_intersection

## [1] FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE

## > trio <- chicago_bulls[logical_intersection, ]

## > trio

## No. Player Pos Ht Wt Birth.Date College

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls # 聯集## > logical_union logical_union## [1] FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE## > trio trio## No. Player Pos Ht Wt Birth.Date College## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## > # 交集## > logical_intersection logical_intersection## [1] FALSE FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE## > trio trio## No. Player Pos Ht Wt Birth.Date College## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

很多有其他程式語言編寫經驗的 R 語言使用者，會在這裡問一個問題：使用 & 與 && 或者使用 | 與 || 的差別為何呢？在 R 語言中連結長度 1 的邏輯值向量，我們使用 && 與 || 。

## > player_name <- "Michael Jordan"

## > player_name == "Michael Jordan" || player_name == "Scottie Pippen"

## [1] TRUE

## > player_name == "Michael Jordan" && player_name == "Scottie Pippen"

## [1] FALSE

假如連結長度大於 1 的邏輯值向量，我們使用 & 與 | 。

## > trio <- c("Michael Jordan", "Scottie Pippen", "Dennis Rodman")

## > trio == "Michael Jordan" | trio == "Scottie Pippen"

## [1] TRUE TRUE FALSE

## > trio == "Michael Jordan" & trio == "Scottie Pippen"

## [1] FALSE FALSE FALSE

連結長度 1 的邏輯值向量若使用 & 與 | 並不會影響結果。

## > player_name <- "Michael Jordan"

## > player_name == "Michael Jordan" | player_name == "Scottie Pippen"

## [1] TRUE

## > player_name == "Michael Jordan" & player_name == "Scottie Pippen"

## [1] FALSE

然而在連結長度大於 1 的邏輯值向量時若使用 && 與 || ，就只會納入位於第一個索引值的邏輯值進行判斷，這不是我們要的結果。

## > trio <- c("Michael Jordan", "Scottie Pippen", "Dennis Rodman")

## > trio == "Michael Jordan" || trio == "Scottie Pippen"

## [1] TRUE

## > trio == "Michael Jordan" && trio == "Scottie Pippen"

## [1] FALSE

假如您是對語法有潔癖的使用者，這是特別為您準備的說明；如果您是一個大而化之的使用者，我們建議您一律使用 & 與 | 即可。

新增與刪除變數、觀測值

直接將欲新增的變數以向量宣告後指派給既有的資料框就能夠完成。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > chicago_bulls$is_starting <- c(FALSE, FALSE, FALSE, FALSE, FALSE, TRUE, TRUE, FALSE, FALSE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE)

## > chicago_bulls

## No. Player Pos Ht Wt Birth.Date College is_starting

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University FALSE

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona FALSE

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama FALSE

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington FALSE

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles FALSE

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University TRUE

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina TRUE

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona FALSE

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968 FALSE

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico TRUE

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas TRUE

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University TRUE

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology FALSE

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College FALSE

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University FALSE ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls chicago_bulls$is_starting chicago_bulls## No. Player Pos Ht Wt Birth.Date College is_starting## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University FALSE## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona FALSE## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama FALSE## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington FALSE## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles FALSE## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University TRUE## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina TRUE## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona FALSE## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968 FALSE## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico TRUE## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas TRUE## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University TRUE## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology FALSE## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College FALSE## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University FALSE

或者將衍生的計算邏輯寫作為函數後以 sapply() 映射至既有的向量，再新增至資料框。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > chicago_bulls$is_starting <- sapply(chicago_bulls$Player, FUN = function(x) x %in% c("Ron Harper", "Michael Jordan", "Scottie Pippen", "Dennis Rodman", "Luc Longley"))

## > chicago_bulls

## No. Player Pos Ht Wt Birth.Date College is_starting

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University FALSE

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona FALSE

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama FALSE

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington FALSE

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles FALSE

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University TRUE

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina TRUE

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona FALSE

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968 FALSE

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico TRUE

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas TRUE

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University TRUE

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology FALSE

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College FALSE

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University FALSE ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls chicago_bulls$is_starting chicago_bulls## No. Player Pos Ht Wt Birth.Date College is_starting## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University FALSE## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona FALSE## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama FALSE## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington FALSE## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles FALSE## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University TRUE## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina TRUE## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona FALSE## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968 FALSE## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico TRUE## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas TRUE## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University TRUE## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology FALSE## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College FALSE## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University FALSE

將欲刪除的變數指派為 NULL 就能完成刪除。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > chicago_bulls$is_starting <- sapply(chicago_bulls$Player, FUN = function(x) x %in% c("Ron Harper", "Michael Jordan", "Scottie Pippen", "Dennis Rodman", "Luc Longley"))

## > chicago_bulls

## No. Player Pos Ht Wt Birth.Date College is_starting

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University FALSE

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona FALSE

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama FALSE

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington FALSE

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles FALSE

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University TRUE

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina TRUE

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona FALSE

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968 FALSE

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico TRUE

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas TRUE

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University TRUE

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology FALSE

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College FALSE

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University FALSE

## > chicago_bulls$is_starting <- NULL

## > chicago_bulls

## No. Player Pos Ht Wt Birth.Date College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls chicago_bulls$is_starting chicago_bulls## No. Player Pos Ht Wt Birth.Date College is_starting## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University FALSE## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona FALSE## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama FALSE## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington FALSE## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles FALSE## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University TRUE## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina TRUE## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona FALSE## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968 FALSE## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico TRUE## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas TRUE## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University TRUE## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology FALSE## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College FALSE## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University FALSE## > chicago_bulls$is_starting chicago_bulls## No. Player Pos Ht Wt Birth.Date College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University

將欲新增的觀測值以資料框的資料結構宣告，再以 rbind() 函數完成新增。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > front_courts <- chicago_bulls[chicago_bulls$Pos %in% c("SF", "PF", "C"), ]

## > back_courts <- chicago_bulls[chicago_bulls$Pos %in% c("PG", "SG"), ]

## > back_courts

## No. Player Pos Ht Wt Birth.Date College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona

## > front_courts

## No. Player Pos Ht Wt Birth.Date College

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University

## > rbind(back_courts, front_courts)

## No. Player Pos Ht Wt Birth.Date College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls front_courts back_courts back_courts## No. Player Pos Ht Wt Birth.Date College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona## > front_courts## No. Player Pos Ht Wt Birth.Date College## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University## > rbind(back_courts, front_courts)## No. Player Pos Ht Wt Birth.Date College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University

刪除觀測值則應用解構資料框的處理方式。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > front_courts <- chicago_bulls[chicago_bulls$Pos %in% c("SF", "PF", "C"), ]

## > front_court_rows <- as.numeric(row.names(front_courts))

## > front_court_rows

## [1] 2 3 4 5 9 10 11 12 13 14 15

## > back_courts <- chicago_bulls[-front_court_rows, ]

## > back_courts

## No. Player Pos Ht Wt Birth.Date College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls front_courts front_court_rows front_court_rows## [1] 2 3 4 5 9 10 11 12 13 14 15## > back_courts back_courts## No. Player Pos Ht Wt Birth.Date College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona

調整變數

利用 colnames() 函數能夠為資料框的變數重新命名。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > colnames(chicago_bulls)

## [1] "No." "Player" "Pos" "Ht" "Wt" "Birth.Date" "College"

## > col_names <- gsub(tolower(colnames(chicago_bulls)), pattern = "\\.", replacement = "_")

## > colnames(chicago_bulls) <- col_names

## > colnames(chicago_bulls)

## [1] "no_" "player" "pos" "ht" "wt" "birth_date" "college" ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls colnames(chicago_bulls)## [1] "No." "Player" "Pos" "Ht" "Wt" "Birth.Date" "College"## > col_names colnames(chicago_bulls) colnames(chicago_bulls)## [1] "no_" "player" "pos" "ht" "wt" "birth_date" "college"

調整變數位置則應用解構資料框的處理方式。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > chicago_bulls

## No. Player Pos Ht Wt Birth.Date College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University

## > ordered_cols <- sort(colnames(chicago_bulls))

## > chicago_bulls <- chicago_bulls[, ordered_cols]

## > chicago_bulls

## Birth.Date College Ht No. Player Pos Wt

## 1 May 22, 1968 University of Houston, New Mexico State University 6-2 0 Randy Brown PG 190

## 2 June 19, 1968 University of Arizona 6-6 30 Jud Buechler SF 220

## 3 June 12, 1973 University of Alabama 6-8 35 Jason Caffey PF 255

## 4 November 22, 1955 University of Washington 7-0 53 James Edwards C 225

## 5 January 27, 1964 University of California, Los Angeles 6-10 54 Jack Haley C 240

## 6 January 20, 1964 Miami University 6-6 9 Ron Harper PG 185

## 7 February 17, 1963 University of North Carolina 6-6 23 Michael Jordan SG 195

## 8 September 27, 1965 University of Arizona 6-3 25 Steve Kerr PG 175

## 9 September 18, 1968 6-10 7 Toni Kukoc SF 192

## 10 January 19, 1969 University of New Mexico 7-2 13 Luc Longley C 265

## 11 September 25, 1965 University of Central Arkansas 6-8 33 Scottie Pippen SF 210

## 12 May 13, 1961 Southeastern Oklahoma State University 6-7 91 Dennis Rodman PF 210

## 13 May 16, 1964 Georgia Institute of Technology 6-11 22 John Salley PF 230

## 14 April 6, 1972 Providence College 6-9 8 Dickey Simpkins PF 248

## 15 April 26, 1963 St. John's University 7-0 34 Bill Wennington C 245 ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls chicago_bulls## No. Player Pos Ht Wt Birth.Date College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University## > ordered_cols chicago_bulls chicago_bulls## Birth.Date College Ht No. Player Pos Wt## 1 May 22, 1968 University of Houston, New Mexico State University 6-2 0 Randy Brown PG 190## 2 June 19, 1968 University of Arizona 6-6 30 Jud Buechler SF 220## 3 June 12, 1973 University of Alabama 6-8 35 Jason Caffey PF 255## 4 November 22, 1955 University of Washington 7-0 53 James Edwards C 225## 5 January 27, 1964 University of California, Los Angeles 6-10 54 Jack Haley C 240## 6 January 20, 1964 Miami University 6-6 9 Ron Harper PG 185## 7 February 17, 1963 University of North Carolina 6-6 23 Michael Jordan SG 195## 8 September 27, 1965 University of Arizona 6-3 25 Steve Kerr PG 175## 9 September 18, 1968 6-10 7 Toni Kukoc SF 192## 10 January 19, 1969 University of New Mexico 7-2 13 Luc Longley C 265## 11 September 25, 1965 University of Central Arkansas 6-8 33 Scottie Pippen SF 210## 12 May 13, 1961 Southeastern Oklahoma State University 6-7 91 Dennis Rodman PF 210## 13 May 16, 1964 Georgia Institute of Technology 6-11 22 John Salley PF 230## 14 April 6, 1972 Providence College 6-9 8 Dickey Simpkins PF 248## 15 April 26, 1963 St. John's University 7-0 34 Bill Wennington C 245

排序資料框

利用 order() 函數取得依據資料大小（英文文字順序）排列所得的列索引值來應用解構資料框的處理方式進行排序。



## > chicago_bulls <- read.csv(csv_url, stringsAsFactors = FALSE)

## > # unsorted

## > chicago_bulls

## No. Player Pos Ht Wt Birth.Date College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University

## > ordered_rows <- order(chicago_bulls$Pos)

## > ordered_rows

## [1] 4 5 10 15 3 12 13 14 1 6 8 2 9 11 7

## > chicago_bulls <- chicago_bulls[ordered_rows, ]

## > # sorted by Position

## > chicago_bulls

## No. Player Pos Ht Wt Birth.Date College

## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington

## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles

## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico

## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University

## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama

## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University

## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology

## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College

## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University

## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University

## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona

## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona

## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968

## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas

## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina ## > csv_url https://s3-ap-northeast-1.amazonaws.com/r-essentials/chicago_bulls_1995_1996.csv ## > chicago_bulls # unsorted## > chicago_bulls## No. Player Pos Ht Wt Birth.Date College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University## > ordered_rows ordered_rows## [1] 4 5 10 15 3 12 13 14 1 6 8 2 9 11 7## > chicago_bulls # sorted by Position## > chicago_bulls## No. Player Pos Ht Wt Birth.Date College## 4 53 James Edwards C 7-0 225 November 22, 1955 University of Washington## 5 54 Jack Haley C 6-10 240 January 27, 1964 University of California, Los Angeles## 10 13 Luc Longley C 7-2 265 January 19, 1969 University of New Mexico## 15 34 Bill Wennington C 7-0 245 April 26, 1963 St. John's University## 3 35 Jason Caffey PF 6-8 255 June 12, 1973 University of Alabama## 12 91 Dennis Rodman PF 6-7 210 May 13, 1961 Southeastern Oklahoma State University## 13 22 John Salley PF 6-11 230 May 16, 1964 Georgia Institute of Technology## 14 8 Dickey Simpkins PF 6-9 248 April 6, 1972 Providence College## 1 0 Randy Brown PG 6-2 190 May 22, 1968 University of Houston, New Mexico State University## 6 9 Ron Harper PG 6-6 185 January 20, 1964 Miami University## 8 25 Steve Kerr PG 6-3 175 September 27, 1965 University of Arizona## 2 30 Jud Buechler SF 6-6 220 June 19, 1968 University of Arizona## 9 7 Toni Kukoc SF 6-10 192 September 18, 1968## 11 33 Scottie Pippen SF 6-8 210 September 25, 1965 University of Central Arkansas## 7 23 Michael Jordan SG 6-6 195 February 17, 1963 University of North Carolina

小結

在這個小節中我們簡介 R 語言的基礎資料框處理技法，包含如何觀察資料框的維度與外觀、查詢資料框的詳細資訊、解構資料框、調整變數以及排序資料框。