R语言数据的查询筛选-subset()

subset(x, subset, select, drop = FALSE, ...)

&多条件查询

 select 显示指定列

selectresult=subset(df1,name=="aa" & sex=="f",select=c(age,sex))

负号排除指定列

selectresult=subset(df1,name=="aa" & sex=="f",select=c(-age,-sex))

例1：从快递帐单表中抽取目的地是辽宁的行

例2：提取目的地是辽宁省，计费重量小于1的数据并且不显示备注

select 显示指定列

selectresult=subset(df1,name=="aa" & sex=="f",select=c(age,sex))

负号排除指定列

selectresult=subset(df1,name=="aa" & sex=="f",select=c(-age,-sex))