json文件以人类可读格式将数据存储为文本。 Json代表javascript Object Notation。 R可以使用rjson包读取JSON文件。
安装rjson包
在R语言控制台中，您可以发出以下命令来安装rjson包。
install.packages("rjson")
输入数据
通过将以下数据复制到文本编辑器（如记事本）中来创建JSON文件。 使用.json扩展名保存文件，并将文件类型选择为所有文件（*.*）。
{
"ID":["1","2","3","4","5","6","7","8" ],
"Name":["Rick","Dan","Michelle","Ryan","Gary","Nina","Simon","Guru" ],
"Salary":["623.3","515.2","611","729","843.25","578","632.8","722.5" ],
"StartDate":[ "1/1/2012","9/23/2013","11/15/2014","5/11/2014","3/27/2015","5/21/2013",
"7/30/2013","6/17/2014"],
"Dept":[ "IT","Operations","IT","HR","Finance","IT","Operations","Finance"]
}
读取JSON文件
JSON文件由R使用来自JSON()的函数读取。 它作为列表存储在R中。
# Load the package required to read JSON files.
library("rjson")
# Give the input file name to the function.
result <- fromJSON(file = "input.json")
# Print the result.
print(result)
当我们执行上面的代码，它产生以下结果 -
$ID [1] "1" "2" "3" "4" "5" "6" "7" "8" $Name [1] "Rick" "Dan" "Michelle" "Ryan" "Gary" "Nina" "Simon" "Guru" $Salary [1] "623.3" "515.2" "611" "729" "843.25" "578" "632.8" "722.5" $StartDate [1] "1/1/2012" "9/23/2013" "11/15/2014" "5/11/2014" "3/27/2015" "5/21/2013" "7/30/2013" "6/17/2014" $Dept [1] "IT" "Operations" "IT" "HR" "Finance" "IT" "Operations" "Finance"
将JSON转换为数据帧
我们可以使用as.data.frame()函数将上面提取的数据转换为R语言数据帧以进行进一步分析。
# Load the package required to read JSON files.
library("rjson")
# Give the input file name to the function.
result <- fromJSON(file = "input.json")
# Convert JSON file to a data frame.
json_data_frame <- as.data.frame(result)
print(json_data_frame)
当我们执行上面的代码，它产生以下结果 -
id, name, salary, start_date, dept 1 1 Rick 623.30 2012-01-01 IT 2 2 Dan 515.20 2013-09-23 Operations 3 3 Michelle 611.00 2014-11-15 IT 4 4 Ryan 729.00 2014-05-11 HR 5 NA Gary 843.25 2015-03-27 Finance 6 6 Nina 578.00 2013-05-21 IT 7 7 Simon 632.80 2013-07-30 Operations 8 8 Guru 722.50 2014-06-17 Finance