Question

我的R代码

data <- read.csv('filename.csv')
typof(data)
[1] "list"

str(data)
    'data frame' : 9 obs. of 10 variables
    $Name: Factor w/9 levels "Name 1", "Name 2",....
    $Column2: chr "","Text1","","Text2"
    $Column3: chr "Text2","Text3","","Text1"
    $Column4: chr "","","","Text1"
#and so on

要求：

我想要的只是$Column2，$Column3，$Column4，......如果有非空值，请添加前缀（Here this is）和后缀（{ {1}}）。因此，考虑以上completed，目前有价值data Column2的第2行应该变为"Text1"

同样在"Here this is Text1 completed."中需要添加前缀和后缀值。

我不想使用循环，除非并且直到需要/必要。

我的尝试：

我尝试了一些尝试，例如Column3: 1st, 2nd and 4th cell，interaction，mget等等，但似乎没有任何效果。

Answer 1

我会按照以下方式对其进行矢量化

indx <- which(data[, -1] != "", arr.ind = TRUE) # Find all non-empty incidences 
data[, -1][indx] <- paste("Here this is", data[, -1][indx], "completed.")

Answer 2

这适用于前4列

apply(data[,2:4],2,function(x) ifelse(x != "",paste("Here this is ",x," completed."),x))

假设每列的前缀和后缀相同。它确实返回一个矩阵，但很容易将其转换为数据帧。希望它有所帮助。

修改：刚刚意识到您的数据位于列表中，因此您需要lapply或sapply。类似的东西：

sapply(data,function(x) ifelse(x != "",paste("Here this is ",x," completed."),x))[,2:4]

也会返回一个矩阵。

Answer 3

以下是set的选项，可以在没有任何复制的情况下进行分配

library(data.table)
setDT(data)
for(j in 2:ncol(data)){
      set(data, i = which(data[[j]]!=""), 
                j = j,
                value = paste("Here there is ",  data[[j]][data[[j]]!=""], " completed."))
    }
data
#     Name                          Column2                          Column3
#1: Name 1                                  Here there is  Text1  completed.
#2: Name 2 Here there is  Text1  completed.                                 
#3: Name 3 Here there is  Text2  completed. Here there is  Text2  completed.
#4: Name 4                                  Here there is  Text3  completed.

数据

data <- structure(list(Name = structure(1:4, .Label = c("Name 1", "Name 2", 
"Name 3", "Name 4"), class = "factor"), Column2 = c("", "Text1", 
 "Text2", ""), Column3 = c("Text1", "", "Text2", "Text3")), .Names = c("Name", 
 "Column2", "Column3"), row.names = c(NA, -4L), class = "data.frame")

Answer 4

使用# dummy data df1 <- mtcars[1:5, 1:3] # add blanks df1[2,2] <- "" df1 # mpg cyl disp # Mazda RX4 21.0 6 160 # Mazda RX4 Wag 21.0 160 # Datsun 710 22.8 4 108 # Hornet 4 Drive 21.4 6 258 # Hornet Sportabout 18.7 8 360 # add prefix and suffix res <- cbind(df1[, 1, drop = FALSE], data.frame( lapply(df1[, -1], function(i) ifelse(i == "", i, paste("Here this is", i, "completed."))))) res # mpg cyl disp # Mazda RX4 21.0 Here this is 6 completed. Here this is 160 completed. # Mazda RX4 Wag 21.0 Here this is 160 completed. # Datsun 710 22.8 Here this is 4 completed. Here this is 108 completed. # Hornet 4 Drive 21.4 Here this is 6 completed. Here this is 258 completed. # Hornet Sportabout 18.7 Here this is 8 completed. Here this is 360 completed.函数（也是循环）：

func setChart(dataPoints: [String], values: [Double]) {
    radarChartView.noDataText = "You need to provide data for the chart."
    var dataEntries: [ChartDataEntry] = []
    for i in 0..<dataPoints.count {
        let dataEntry = ChartDataEntry(value: values[i], xIndex: i)
        dataEntries.append(dataEntry)
    }
    let chartDataSet = RadarChartDataSet(yVals: dataEntries, label: "Units Sold")

    //Set options...

    //Then set data
    let chartData = RadarChartData(xVals: subjects, dataSet: chartDataSet)
}

Answer 5

DF = transform(ifelse(data$Column2 == "", data$Column2, sprintf('Here it is %s completed', data$Column2)))
DF <- data.frame (DF, data$Name, data$Column3)

为列表值R添加前缀和后缀

5 个答案:

数据