假设我有一个数据集A,其中包括关于月份("日期"(的信息:
站点ID | 降水量(mm( | > | >LONG | LAT | 日期|
---|---|---|---|---|---|
1 | 70 | 5 | 50 | 2010-01 | |
1 | 60 | 5 | 50 | 2010-02 | |
1 | 61 | 5 | 50 | 2010-03 | |
2 | 75 | 10 | 47 | 2010-01 | |
2 | 65 | 10 | 47 | 2010-02 | |
2 | 70 | 10 | 47 | 2010-03 |
使用data.table
的拆分,这是非常简单的
library(data.table)
# make sure your data in in a data.table format
setDT(mydata)
# use split.data.table to split on a certain column
split(mydata, by = "Date")
# $`2010-01`
# station_ID precipitation LONG LAT Date
# 1: 1 70 5 50 2010-01
# 2: 2 75 10 47 2010-01
#
# $`2010-02`
# station_ID precipitation LONG LAT Date
# 1: 1 60 5 50 2010-02
# 2: 2 65 10 47 2010-02
#
# $`2010-03`
# station_ID precipitation LONG LAT Date
# 1: 1 61 5 50 2010-03
# 2: 2 70 10 47 2010-03