如何将行添加到数据框？

香港专业教育学院尝试了很多不同的东西，但我不知道如何添加一行到这个表如何将行添加到数据框？

means <- data.frame("State" = character(0), "Mean" = numeric(0))

我以为是这样的

for (state in unique(data$State)){ 
    means <- rbind(means, c("state", 4)) 
}

但是，当我尝试打印表格它给我关于不同级别的警告。

44: In `[<-.factor`(`*tmp*`, ri, value = structure(c(1L, NA, ... : 
    invalid factor level, NA generated 
45: In `[<-.factor`(`*tmp*`, ri, value = structure(c(1L, NA, ... : 
    invalid factor level, NA generated

编辑：

打印（州）打印此

[1] "Arizona" 
[1] "California" 
[1] "Colorado" 
[1] "District Of Columbia" 
[1] "Florida" 
[1] "Illinois" 
[1] "Indiana" 
[1] "Kansas" 
[1] "Kentucky" 
[1] "Louisiana" 
[1] "Michigan" 
[1] "Missouri" 
[1] "New Jersey" 
[1] "New York" 
[1] "North Carolina" 
[1] "Oklahoma" 
[1] "Pennsylvania" 
[1] "Texas" 
[1] "Virginia" 
[1] "Massachusetts" 
[1] "Nevada" 
[1] "New Hampshire" 
[1] "Tennessee" 
[1] "South Carolina" 
[1] "Connecticut" 
[1] "Iowa" 
[1] "Maine" 
[1] "Maryland" 
[1] "Wisconsin" 
[1] "Country Of Mexico" 
[1] "Arkansas" 
[1] "Oregon" 
[1] "Wyoming" 
[1] "North Dakota" 
[1] "Idaho" 
[1] "Ohio" 
[1] "Georgia" 
[1] "Delaware" 
[1] "Hawaii" 
[1] "Minnesota" 
[1] "New Mexico" 
[1] "Rhode Island" 
[1] "South Dakota" 
[1] "Utah" 
[1] "Alabama" 
[1] "Washington" 
[1] "Alaska"

来源

2016-11-15 k9b

什么是'数据$ State'？这是否是一个因素，如果是这样的话，是''状态''数据$状态'中的一个级别？ – aichao

作出的编辑到原来的职位 – k9b

所以，你要创建一个50行（每个国家），其中每行是'data.frame数据帧（州=“状态”，“中庸” = 4）' ？ – aichao

您尝试添加一个矢量，并与数据帧里面是不是最好的选择rbind它。你最好rbind a data.frame到data.frame。

所以你的情况更好地做到：

for (state in unique(data$state)) { 
    means<-rbind(means, data.frame(State=state,Mean=4) 
}

来源

2016-11-15 16:15:28

如何将行添加到数据框？

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