数据的汇总
数据的汇总对数据进行汇总,分类汇总是我们也比较常用的,比如对行或列求和,求均值,求分位数: data <- matrix(1:16, 4, 4)data
apply(data, 2, mean)
apply(data, 1, sum)
apply(data, 1, quantile, probs = c(0.25, 0.75))
apply(data, 2, quantile, probs = c(0.25, 0.75))
有时候,为了更快些,我们会用一些函数替代apply:
我们有时也会处理一些列表,对列表的分类汇总我们会用到sapply,lapply,不同的是前者返回一个向量或矩阵,后者返回一个列表,例: x <- list(a = 1:10, beta = exp(-3:3), logic = c(TRUE,FALSE,FALSE,TRUE)) lapply(x, mean)
sapply(x, mean)
# median and quartiles for each list elementlapply(x, quantile, probs = 1:3/4)
sapply(x, quantile)
有时候我们还会进行分类汇总,如统计男女工资均值,这时你可以用tapply: group <- (rbinom(32, n = 20, prob = 0.4))groups <- factor(rep(1:2,10)) tapply(group, groups, length)
tapply(group, groups, sum)
tapply(group, groups, mean)
|
|广告服务|关于我们|Archiver|手机版|小黑屋|大数据人 ( 鄂ICP备14012176号-2 )
GMT+8, 2024-5-12 13:43 , Processed in 0.181867 second(s), 22 queries .
Powered by 小雄! X3.2
© 2014-2020 bigdataer Inc.