简化数据框列表的提取

Question

我的问题是以下问题的延续。（由于声誉限制无法对该线程发表评论）

Print the Nth Row in a List of Data Frames

我希望将结果打印为数据框而不是列表（假设我有多个列而不是示例中的单个列）。有人能告诉我我需要做什么才能得到这个输出吗？

输入样本列表

    $AK
                    HospitalName State HeartAttack HeartFailure Pneumonia
    99  PROVIDENCE ALASKA MEDICAL CENTER    AK        13.4         12.4      10.5
    103         ALASKA REGIONAL HOSPITAL    AK        14.5         13.4      12.5
    102      FAIRBANKS MEMORIAL HOSPITAL    AK        15.5         15.6      13.4
    106     ALASKA NATIVE MEDICAL CENTER    AK        15.7         11.6      15.5
    100   MAT-SU REGIONAL MEDICAL CENTER    AK        17.7         11.4      12.1

    $AL
                                  HospitalName State HeartAttack HeartFailure Pneumonia
    78                        CRESTWOOD MEDICAL CENTER    AL        13.3         13.8      10.4
    85                     BAPTIST MEDICAL CENTER EAST    AL        14.2          9.6      10.2
    1                 SOUTHEAST ALABAMA MEDICAL CENTER    AL        14.3         11.4      10.9
    31                              GEORGIANA HOSPITAL    AL        14.5         10.8      11.3
    65                     PRATTVILLE BAPTIST HOSPITAL    AL        14.6         14.8      14.2
    60                                 THOMAS HOSPITAL    AL        14.7         12.8      13.1
    71           VAUGHAN REG MED CENTER PARKWAY CAMPUS    AL        14.7         12.0      14.0

预期输出样本（假设 num = 4，即提取每个数据帧的第 4 行）

    HospitalName State HeartAttack HeartFailure Pneumonia
    106     ALASKA NATIVE MEDICAL CENTER    AK        15.7         11.6      15.5
    65                     PRATTVILLE BAPTIST HOSPITAL    AL        14.6         14.8      14.2

我用过的lapply代码是printtab<-lapply(finaltab,'[',num,drop=FALSE)

finaltab 是一个数据帧列表，其中每个数据帧包含 5 列，num 用于从每个数据帧中提取 1 个特定行，printtab 是输出列表

我尝试过的事情：

在 lapply 中添加 simplify=TRUE: 它给出了一个错误
使用 sapply 作为 printtab<-sapply(finaltab,'[',num,drop=FALSE): 它说缺少参数，没有默认值。试过没有下降嗯。

使用as.data.frame()：它做了一些我不明白的事情

AK.HospitalName AK.State AK.HeartAttack AK.HeartFailure AK.Pneumonia                AL.HospitalName AL.State
NA            <NA>     <NA>           <NA>            <NA>         <NA> D W MCMILLAN MEMORIAL HOSPITAL       AL
   AL.HeartAttack AL.HeartFailure AL.Pneumonia                   AR.HospitalName AR.State AR.HeartAttack AR.HeartFailure
NA           15.7            14.8         12.6 ARKANSAS METHODIST MEDICAL CENTER       AR           17.1            14.4
   AR.Pneumonia                     AZ.HospitalName AZ.State AZ.HeartAttack AZ.HeartFailure AZ.Pneumonia
NA         11.7 JOHN C LINCOLN DEER VALLEY HOSPITAL       AZ           14.9            11.9         10.0
         CA.HospitalName CA.State CA.HeartAttack CA.HeartFailure CA.Pneumonia          CO.HospitalName CO.State
NA SHERMAN OAKS HOSPITAL       CA           13.3             9.7          9.3 SKY RIDGE MEDICAL CENTER       CO
   CO.HeartAttack CO.HeartFailure CO.Pneumonia         CT.HospitalName CT.State CT.HeartAttack CT.HeartFailure CT.Pneumonia
NA           15.0             9.9         10.5 MIDSTATE MEDICAL CENTER       CT           15.6            12.1         11.4
   DC.HospitalName DC.State DC.HeartAttack DC.HeartFailure DC.Pneumonia DE.HospitalName DE.State DE.HeartAttack
NA            <NA>     <NA>           <NA>            <NA>         <NA>            <NA>     <NA>           <NA>
   DE.HeartFailure DE.Pneumonia                FL.HospitalName FL.State FL.HeartAttack FL.HeartFailure FL.Pneumonia

编辑：

dput(head(finaltab)) 的示例输出

    structure(list(AK = structure(list(HospitalName = c("PROVIDENCE ALASKA  MEDICAL CENTER", 
"ALASKA REGIONAL HOSPITAL", "FAIRBANKS MEMORIAL HOSPITAL", "ALASKA NATIVE MEDICAL CENTER", 
"MAT-SU REGIONAL MEDICAL CENTER"), State = c("AK", "AK", "AK", 
"AK", "AK"), HeartAttack = c("13.4", "14.5", "15.5", "15.7", 
"17.7"), HeartFailure = c("12.4", "13.4", "15.6", "11.6", "11.4"
), Pneumonia = c("10.5", "12.5", "13.4", "15.5", "12.1")), .Names = c("HospitalName", 
"State", "HeartAttack", "HeartFailure", "Pneumonia"), row.names = c(99L, 
103L, 102L, 106L, 100L), class = "data.frame"), AL = structure(list(
    HospitalName = c("CRESTWOOD MEDICAL CENTER", "BAPTIST MEDICAL CENTER EAST", 
    "SOUTHEAST ALABAMA MEDICAL CENTER", "GEORGIANA HOSPITAL",

lapply

上 rbind 的输出

AK     AL     AR     AZ     CA     CO     CT     DC     DE     FL     GA     GU     HI     IA     ID     IL     IN    
[1,] List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5
     KS     KY     LA     MA     MD     ME     MI     MN     MO     MS     MT     NC     ND     NE     NH     NJ     NM    
[1,] List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5
     NV     NY     OH     OK     OR     PA     PR     RI     SC     SD     TN     TX     UT     VA     VI     VT     WA    
[1,] List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5 List,5
     WI     WV     WY    
[1,] List,5 List,5 List,5

Answer 1

df.meeshu有dput的输出。您的代码没有任何关于将您拥有的 csv 文件转换为 dput 输出的信息。所以我只是使用了 dput。使用你自己的数据框，它是 finaltab 代替 df.meeshu

df.list.select <-lapply(df.meeshu, function(x) x[4,])
df.select <-do.call("rbind", df.list.select)
head(df.select)

你也可以用plyr，可能会更快

library(plyr)
rbind.fill(df.list.select)

简化数据框列表的提取

Simplify extraction of list of data frame

r

lapply

dataframe