-
#向量 #生成一個指定長度和類型的空向量 X <- vector("character",length = 10) #包含左邊數字的向量，偏移量為1，數據類型以左邊數字為準 X1 <- 5.5:-2 #指定向量 X2 <- c(1,3,5,7,1.2) #自動強制轉換數據類型(優先級：字符>復數>數值>整數>邏輯) X3 <- c(TRUE,12L,12,12+12i,"ww") #指定類型強制轉換,引入缺失類型NA（強轉不了的） #字符 as.character(X3) #復數 as.complex(X3) #數值 as.numeric(X3) #整數 as.integer(X3) #邏輯 as.logical(X3) #給向量加名稱 class(X2) names(X2) <- c("a1","a2","a3","a4","a5") X2查看全部
-
數據框(data frame)
? ? 一、存儲表格數據(tabular data)
? ? 二、視為各元素長度相同的列表
? ? ? ? ?? (1)每個元素代表一列數據
? ? ? ? ?? (2)每個元素的長度代表行數
? ? ? ? ?? (3)元素類型可以不同 ? ?
創建數據框：df <- data.frame(id = c(1,2,3,4), name = c("a","b","c","d"), gender = c(TRUE,TRUE,FALSE,FALSE))
查看數據框行列數：nrow(df), ncol(df)
某些特殊的數據框(每個元素的數據類型一樣)可以轉換為矩陣：
data.matrix(df2) ? ? ? ? ?? (df2為一元素數據類型一樣的數據框)
查看全部 -
缺失值(missing value)
一、NA/NaN:NaN屬于NA,NA不屬于NaN(NaN一般表示的是數字的缺失值，NA廣泛一點兒)
二、NA有類型屬性：integer NA, character NA等
三、is.na()/is.nan() (判斷是否有缺失值)
查看全部 -
列表
l <- list("a", 2, 10L, 3+4i, TRUE)
列表命名
l2 <- list(a=1, b=2, c=3)?
列表中每個元素中的元素個數大于1
l3 <- list(c(1,2,3), c(4,5,6,7))
矩陣行列命名
dimnames(x) <- list(c("a","b"), c("c","d","e")) ? ?
(x是一個矩陣，a.b是行的名字，d,e是列的名字)
查看全部 -
矩陣的創建(行列): x <- matrix(nrow = 3, ncol = 2)
? ? ? ? ? ? ? ? ? ? ? ? ? ? x <-matrix(1:6, nrow = 3, ncol = 2)
矩陣的維度：dim(x)
屬性：attributes(x)
矩陣按行(行增加)拼接：rbind(x,y)；按列拼接：cbind(x,y).
創建數組：x <- array(1:24,dim=c(4,6))
? ? ? ? ? ? ? ?? x <- array(1:24,dim=c(2,3,4))
查看全部 -
>?o?<-?array(1:100,dim?=?c(4,5,4))>?o,?,?1 ?????[,1]?[,2]?[,3]?[,4]?[,5] [1,]????1????5????9???13???17 [2,]????2????6???10???14???18 [3,]????3????7???11???15???19 [4,]????4????8???12???16???20 ,?,?2 ?????[,1]?[,2]?[,3]?[,4]?[,5] [1,]???21???25???29???33???37 [2,]???22???26???30???34???38 [3,]???23???27???31???35???39 [4,]???24???28???32???36???40 ,?,?3 ?????[,1]?[,2]?[,3]?[,4]?[,5] [1,]???41???45???49???53???57 [2,]???42???46???50???54???58 [3,]???43???47???51???55???59 [4,]???44???48???52???56???60 ,?,?4 ?????[,1]?[,2]?[,3]?[,4]?[,5] [1,]???61???65???69???73???77 [2,]???62???66???70???74???78 [3,]???63???67???71???75???79 [4,]???64???68???72???76???80
> 查看全部 -
>?o?<-?array(1:100,dim?=?c(20,5))>?o??????[,1]?[,2]?[,3]?[,4]?[,5] ?[1,]????1???21???41???61???81 ?[2,]????2???22???42???62???82 ?[3,]????3???23???43???63???83 ?[4,]????4???24???44???64???84 ?[5,]????5???25???45???65???85 ?[6,]????6???26???46???66???86 ?[7,]????7???27???47???67???87 ?[8,]????8???28???48???68???88 ?[9,]????9???29???49???69???89 [10,]???10???30???50???70???90 [11,]???11???31???51???71???91 [12,]???12???32???52???72???92 [13,]???13???33???53???73???93 [14,]???14???34???54???74???94 [15,]???15???35???55???75???95 [16,]???16???36???56???76???96 [17,]???17???37???57???77???97 [18,]???18???38???58???78???98 [19,]???19???39???59???79???99 [20,]???20???40???60???80??100
> 查看全部 -
>?cbind(p,q)?????[,1]?[,2]?[,3]?[,4]?[,5]?[,6] [1,]????1????4????7???-1???-4???-7 [2,]????2????5????8???-2???-5???-8 [3,]????3????6????9???-3???-6???-9>?cbind9q,pError:?unexpected?','?in?"cbind9q,">?cbind(q,p)?????[,1]?[,2]?[,3]?[,4]?[,5]?[,6] [1,]???-1???-4???-7????1????4????7 [2,]???-2???-5???-8????2????5????8 [3,]???-3???-6???-9????3????6????9>?x?<-?c(1:20,dim(4,5))Error?in?dim(4,?5)?:?2?arguments?passed?to?'dim'?which?requires?1>?x?<-?matrix(1:20,dim(4,5))Error?in?dim(4,?5)?:?2?arguments?passed?to?'dim'?which?requires?1>?x?<-?array(1:20,dim(4,5))Error?in?dim(4,?5)?:?2?arguments?passed?to?'dim'?which?requires?1>?h?<-?array(1:16,dim(2,8))Error?in?dim(2,?8)?:?2?arguments?passed?to?'dim'?which?requires?1>?h?<-?array(1:16,dim?<-?(2,8))Error:?unexpected?','?in?"h?<-?array(1:16,dim?<-?(2,">?h?<-?array(1:16,dim?=?(2,8))Error:?unexpected?','?in?"h?<-?array(1:16,dim?=?(2,">?h?<-?array(1:16,dim?=?c(2,8))>?h?????[,1]?[,2]?[,3]?[,4]?[,5]?[,6]?[,7]?[,8] [1,]????1????3????5????7????9???11???13???15 [2,]????2????4????6????8???10???12???14???16
> 查看全部 -
>?w?<-?matrix(1:12,nrow?=?2,ncol?=?6)>?w?????[,1]?[,2]?[,3]?[,4]?[,5]?[,6] [1,]????1????3????5????7????9???11 [2,]????2????4????6????8???10???12>?dim(w)[1]?2?6>?attributes(w)$dim [1]?2?6>?j?<-?1:10>?dim(j)?<-?c(5,2)>?j?????[,1]?[,2] [1,]????1????6 [2,]????2????7 [3,]????3????8 [4,]????4????9 [5,]????5???10>?rbind(w,j)Error?in?rbind(w,?j)?:? ??number?of?columns?of?matrices?must?match?(see?arg?2)>?p?<-?matrix(1:9,nrow?=?3,ncol?=?3)>?p?????[,1]?[,2]?[,3] [1,]????1????4????7 [2,]????2????5????8 [3,]????3????6????9>?q?<-?matrix(-1:-9,nrow?=?3,ncol?=?3)>?q?????[,1]?[,2]?[,3] [1,]???-1???-4???-7 [2,]???-2???-5???-8 [3,]???-3???-6???-9>?rbind(p,q)?????[,1]?[,2]?[,3] [1,]????1????4????7 [2,]????2????5????8 [3,]????3????6????9 [4,]???-1???-4???-7 [5,]???-2???-5???-8 [6,]???-3???-6???-9>?rbind(q,p)?????[,1]?[,2]?[,3] [1,]???-1???-4???-7 [2,]???-2???-5???-8 [3,]???-3???-6???-9 [4,]????1????4????7 [5,]????2????5????8 [6,]????3????6????9
> 查看全部 -
>?k?<-?matrix(3,4)>?k?????[,1] [1,]????3 [2,]????3 [3,]????3 [4,]????3>?l?<-?matrix(1:16,4)>?l?????[,1]?[,2]?[,3]?[,4] [1,]????1????5????9???13 [2,]????2????6???10???14 [3,]????3????7???11???15 [4,]????4????8???12???16>?l?<-?matrix(1:16,4,4)>?l?????[,1]?[,2]?[,3]?[,4] [1,]????1????5????9???13 [2,]????2????6???10???14 [3,]????3????7???11???15 [4,]????4????8???12???16
查看全部 -
>?y?<-?"hello?world">?y[1]?"hello?world">?class(y)[1]?"character">?y?<-?TRUE>?y[1]?TRUE>?class(y)[1]?"logical">?y?<-?1+iError:?object?'i'?not?found>?y?<-?1+2i>?y[1]?1+2i>?class(y)[1]?"complex">?y?<-?1-iError:?object?'i'?not?found>?y?<-?i+1Error:?object?'i'?not?found>?length(y)[1]?1>?m?<-?1+2i>?length(m)[1]?1>?x?<-?vector("number",length?=?10)Error?in?vector("number",?length?=?10)?:? ??vector:?cannot?make?a?vector?of?mode?'number'.>?x?<-?vector("numeric",length?=?10)>?x?[1]?0?0?0?0?0?0?0?0?0?0>?x?<-?vector("character",length?=?10)>?x?[1]?""?""?""?""?""?""?""?""?""?"">?x?<-?vector("character",length?=?10)>?x?<-?vector("character",length?=?10)>?x?<-?vector("character",length?=?10)>?x?<-?vector("character",length?=?10)>?x?<-?1:16>?x?[1]??1??2??3??4??5??6??7??8??9?10?11?12?13?14?15?16>?x??<-?1:100>?x??[1]???1???2???3???4???5???6???7???8???9??10??11??12??13??14??15??16??17??18??19??20??21??22??23??24??25??26??27??28??29 ?[30]??30??31??32??33??34??35??36??37??38??39??40??41??42??43??44??45??46??47??48??49??50??51??52??53??54??55??56??57??58 ?[59]??59??60??61??62??63??64??65??66??67??68??69??70??71??72??73??74??75??76??77??78??79??80??81??82??83??84??85??86??87 ?[88]??88??89??90??91??92??93??94??95??96??97??98??99?100>?x?<-?c(1,2,3,4)>?t?<-?c(1,2,3)>?t[1]?1?2?3>?as.numeric(t)[1]?1?2?3>?u?<-?c(1,3,5)>?as.numeric(u)[1]?1?3?5>?as.character(u)[1]?"1"?"3"?"5">?u?<-?c(1,3,5)>?#as.numeric(u)>?as.character(u)[1]?"1"?"3"?"5">?v?<-?c(100,200)>?as.character(v)[1]?"100"?"200">?as.logical(v)[1]?TRUE?TRUE>?b?<-?c(0,1,0)>?as.logical(b)[1]?FALSE??TRUE?FALSE>?class(b)[1]?"numeric">?class(v)[1]?"numeric">?class(as.character(v))[1]?"character">?names(b)?<-?c("上","中","下")>?b上?中?下? ?0??1??0? >?names(v)?<-?c("一班成績","二班成績")>?v一班成績?二班成績? ?????100??????200> 查看全部 -
sapply和split通常與lapply結合使用
查看全部 -
object.size(函數)可以查看函數大小，返回結果的單位是字節。
print(object.size(函數),units="Kb")可以將結果的單位變成Kb
查看全部 -
交叉表函數xtabs(Freq~變量1+變量2，數據)可以查看滿足變量1和2的結果數，ftable()使結果變得扁平化
查看全部 -
any(is.na())返回邏輯元素，表示是否存在缺失值，sum(is.na())總結缺失值數量
all(條件)表示判斷條件是否正確，返回邏輯元素
查看全部
舉報
0/150
提交
取消