Use the built-in data set "airquality".
1. Extract the first 4 rows of the data frame and print them to the console.
目前分類：R語言 (22)
- May 09 Wed 2018 23:18
Reading and Writing Data 抓出指定變數或觀測值
- May 08 Tue 2018 15:32
建立txt檔並將NA value轉換成"."
Write the built-in data set "airquality" to a Tab-separated text file with write.table. View it with a text editor (depending on your system). Change the NA value to . (period), and read the changed file back into R with a suitable command.
生物資訊 (4)
