我在 R 中有一个看起来像这样的对象:
returns
2010-1-4 -0.015933327
2010-1-11 -0.015042868
2010-1-18 0.005350297
2010-1-25 -0.049324703
2010-2-1 -0.052674121
我想把它变成:
date returns
1 2010-01-04 -0.0159333272
2 2010-01-11 -0.0150428685
3 2010-01-18 0.0053502965
4 2010-01-25 -0.0493247026
5 2010-02-01 -0.0526741206
我该怎么做?
最佳答案
根据 rownames
新建一栏你的数据集:
# Read in your example data
DF = read.table(header=TRUE, text=" returns
2010-1-4 -0.015933327
2010-1-11 -0.015042868
2010-1-18 0.005350297
2010-1-25 -0.049324703
2010-2-1 -0.052674121")
DF
# returns
# 2010-1-4 -0.015933327
# 2010-1-11 -0.015042868
# 2010-1-18 0.005350297
# 2010-1-25 -0.049324703
# 2010-2-1 -0.052674121
# Create a `date` variable
DF$date = rownames(DF)
# Reset the `rownames` of your original data
rownames(DF) = NULL
# Format the `date` variable properly
DF$date = strptime(DF$date, "%Y-%m-%d")
DF
# returns date
# 1 -0.015933327 2010-01-04
# 2 -0.015042868 2010-01-11
# 3 0.005350297 2010-01-18
# 4 -0.049324703 2010-01-25
# 5 -0.052674121 2010-02-01
关于r - 如何创建行名变量?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/11427434/