Question

表格如下所示，SampleID和Number是列名：

SampleID Number
G2Day2   15
G2Day4   11
G11Day13 5

我想使用SampleID中的值创建另一列，因此新表格如下所示：

SampleID Group Day Number
G2Day2   G2    2   15
G2Day4   G2    4   11
G11Day13 G11   13  5

Answer 1

您可以使用strsplit将结果列表中的sampleID和rbind分开。

df[, c("Group", "Day")] <- do.call(rbind, strsplit(as.character(df[, "SampleID"]), "Day"))
df[, c("SampleID", "Group", "Day", "Number")]
##   SampleID Group Day Number
## 1   G2Day2    G2   2     15
## 2   G2Day4    G2   4     11
## 3 G11Day13   G11  13      5

Answer 2

gsub可以很容易地完成这项特殊任务。试试这个：

df$Group <- gsub(pattern = "Day.*", replacement = "", x=df$SapmleID)
df$Number <- gsub(pattern = ".*Day", replacement = "", x=df$SampleID)

。*是一个表示任意数量字符的正则表达式

Answer 3

这是一个tidyr解决方案

library(tidyr)
cbind(df[1], separate(df, SampleID, c("Group", "Day"), "Day"))
#   SampleID Group Day Number
# 1   G2Day2    G2   2     15
# 2   G2Day4    G2   4     11
# 3 G11Day13   G11  13      5

或类似于data.table v >= 1.9.5

library(data.table) # v 1.9.5
setDT(df)[,  c("Group", "Day") := tstrsplit(as.character(SampleID), "Day")][]
#    SampleID Number Group Day
# 1:   G2Day2     15    G2   2
# 2:   G2Day4     11    G2   4
# 3: G11Day13      5   G11  13

Answer 4

带一点正则表达式：

dat <- read.table(header = TRUE, text="SampleID Number
G2Day2   15
G2Day4   11
G11Day13 5")

within(dat, {
  Group <- gsub('Day\\d+', '', SampleID)
  Day <- gsub('.*Day(.*)', '\\1', SampleID)
})

#   SampleID Number Day Group
# 1   G2Day2     15   2    G2
# 2   G2Day4     11   4    G2
# 3 G11Day13      5  13   G11

Answer 5

如果您的新表已有列名这样的事情就是你要做的。伪代码在这里：



    foreach(Datarow row in myoriginaltable.rows)
    {
    int i = 0;
    // Get an index reference to the row you create and add to the new table
    i = myNewTable.AddRow(new DataRow);

myNewTable.Rows[i].Column["Number"] = row.Column["Number"];
// where ColumnName is the name of your column that you want to transfer from one to the other.
myNewTable.Rows[i].Column["ColumnName"] = row.Column["ColumnName"];

// Create a Column , give it a value from the row and Column["ColumnName"] 
DataColumn dc = new DataColumn(row.Column["ColumnName"].Value.ToString());
myNewTable.Columns.Add(dc);
}
</code></pre>

使用其他列中的某些值创建另一列

5 个答案: