而聚合函数(Aggregate Function)则是在分组的基础上,对每个组内的数据进行统计计算,如求和、平均值、最大值、最小值等。 相关优势 简化数据分析:通过分组和聚合,可以将大量复杂的数据简化为更有意义的小块,便于理解和分析。 提高查询效率:数据库管理系统通常会对分组和聚合操作进行优化,从而提高查询效率。 支持多种...
aggregate(cbind(Ozone, Temp) ~ Month, data = airquality, mean) aggregate(cbind(ncases, ncontrols) ~ alcgp + tobgp, data = esoph, sum) ## Dot notation: aggregate(. ~ Species, data = iris, mean) aggregate(len ~ ., data = ToothGrowth, mean) ## Often followed by xtabs(): ag <...
aggregate(len ~ ., data = ToothGrowth, mean)## Often followed by xtabs():ag <- aggregate(len ~ ., data = ToothGrowth, mean) xtabs(len ~ ., data = ag)## Compute the average annual approval ratings for American presidents.aggregate(presidents, nfrequency = 1, FUN = mean)## Give the...
使用aggregate()来实现分组计数,使用length(x)来计算向量中元素的个数,该函数会把重复值计算N次: aggregate(cut~color,diamonds,length) 1. 为了计算唯一值的数量,可以使用unique(x),在计数之前,对向量元素去重: aggregate(cut~color,diamonds,function(x) length(unique(x))) 1. 三,数据变换(dplyr包) dplyr包...
The aggregate function is more difficult to use, but it is included in the base R installation and does not require the installation of another package. # Get a count of number of subjects in each category (sex*condition) cdata <- aggregate(data["subject"], by=data[c("sex","condition"...
aggregate(x, nfrequency = 1, FUN = sum, ndeltat = 1, ts.eps = getOption("ts.eps"), ...) 语法 aggregate(x, ...) ## S3 method for class ‘default‘: aggregate((x, ...)) ## S3 method for class ‘data.frame‘: aggregate((x, by, FUN, ..., simplify = TRUE)) ...
aggregate(x, ...) ## S3 method for class 'default': aggregate((x, ...)) ## S3 method for class 'data.frame': aggregate((x, by, FUN, ..., simplify = TRUE)) ## S3 method for class 'formula': aggregate((formula, data, FUN, ..., ...
probe2gene <- function (probe_exp, anno, gene_col, FUN) { gene_exp <- aggregate( probe_exp, by = list( gene=anno[rownames(probe_exp), gene_col] ), FUN = FUN ) rownames(gene_exp) <- gene_exp$gene gene_exp$gene <- NULL ...
ID=sample(x = as.character(1:4), size = 200000, replace = TRUE))Aggregate(x=data,by='ID')# Examples of how to use the object and p argument. See dummy and categories function for details.# Aggregate(x=data,by='ID',object=categories(data))# Aggregate(x=data,by='ID',p=2)...
R语言分组聚合统计的常用函数是aggregate函数。 aggregate(x,by, FUN) aggregate(x = any_data, by = group_list, FUN = any_function) # Basic R syntax of aggregate x是待分组的数据对象、一般是dataframe数据; by是变量名组成的列表list,需要注意的是即使是一个变量也需要使用列表的形式来表达...