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20150920
[Coursera]
R Programming
(5)
整理自
R Programming
(Week
1)
--
Subsetting Data
[ Week 1 課程內容 ]
Introduction
(略過)
Overview and History of R
[16:07]
(完成)
Getting Help
[13:53]
(略過)
Console Input and Evaluation
[4:46]
(完成)
Data Types - R Objects and Attributes
[4:43]
(完成)
Data Types - Vectors and Lists
[6:27]
(完成)
Data Types - Matrices
[3:24]
(完成)
Data Types - Factors
[4:31]
(完成)
Data Types - Missing Values
[2:10]
(完成)
Data Types - Data Frames
[2:44]
(完成)
Data Types - Names Attribute
[1:49]
(完成)
Data Types - Summary
[0:43]
(完成)
Reading Tabular Data
[5:51]
(完成)
Reading Large Tables
[7:08]
(完成)
Textual Data Formats
[4:58]
(完成)
Connections: Interfaces to the Outside World
[4:35]
(完成)
Subsetting - Basics
Subsetting - Lists
Subsetting - Matrices
Subsetting - Partial Matching
Subsetting - Removing Missing Values
Vectorized Operations
[3:46]
Introduction to swirl
[ 本次筆記內容 ] Subsetting Data
(一)Subsetting - Basics
(二)Subsetting - Lists
(三)Subsetting - Matrices
(四)Subsetting - Partial Matching
(五)Subsetting - Removing Missing Values
[ 背景知識 ] 基本運算元
有一些
基本運算元
可以提取 R 物件裡的內容 :
單個中括號 :
[
...
]
其回傳值為與
原向量相同類別
的物件
,可以回傳數個以上的元素。(有例外)
[
例如
] 提取
雙個中括號 :
[[
...
]]
用來
提取
"列表"
(list)
或
"資料框"
(data
frame)
。
只能回傳單一元素
且其回傳值不是"列表"
(list)
或
"資料框"
(data
frame)。
金額符號 :
$
藉由
"列表"
(list)
或
"資料框"
(data
frame)
的名稱
來提取元素。
在意義上跟
雙個中括號
[[
...
]]
很像。
[ 補充資料 ]
Please turn on JavaScript to use Paper in all of its awesomeness. ^_^
整理自 R Programming (Week 1) -- Subsetting Data
Introduction(略過)Overview and History of R[16:07](完成)Getting Help[13:53] (略過)Console Input and Evaluation[4:46](完成)Data Types - R Objects and Attributes[4:43](完成)Data Types - Vectors and Lists[6:27](完成)Data Types - Matrices[3:24](完成)Data Types - Factors[4:31](完成)Data Types - Missing Values[2:10](完成)Data Types - Data Frames[2:44](完成)Data Types - Names Attribute[1:49](完成)Data Types - Summary[0:43](完成)Reading Tabular Data[5:51](完成)Reading Large Tables[7:08](完成)Textual Data Formats[4:58](完成)Connections: Interfaces to the Outside World[4:35](完成)