table

table统计数据的频数。

The table command is one of the most basic summary statistics functions in R, it runs through the vector you gave it and simply counts the occurrence of each value in it。

就是按照不同的因子來統計頻數的。很类似group by 。

eg:

# 类别为table
> class(table(seq(1,10)))
[1] "table"

## 0,1
> table(train$Survived)

## Check the design:
with(warpbreaks, table(wool, tension))
table(state.division, state.region)

# simple two-way contingency table
# 处理连续值 
with(airquality, table(cut(Temp, quantile(Temp)), Month))