如何使用R在数据框的列中查找前n％个记录 [英] How to find top n% of records in a column of a dataframe using R

问题描述

我有一个数据集，显示了大约20年内每天一次的澳元兑美元的汇率.我将数据存储在数据框中，第一列是日期，第二列是汇率.这是来自数据的示例:

I have a dataset showing the exchange rate of the Australian Dollar versus the US dollar once a day over a period of about 20 years. I have the data in a data frame, with the first column being the date, and the second column being the exchange rate. Here's a sample from the data:

>data
             V1     V2
1    12/12/1983 0.9175
2    13/12/1983 0.9010
3    14/12/1983 0.9000
4    15/12/1983 0.8978
5    16/12/1983 0.8928
6    19/12/1983 0.8770
7    20/12/1983 0.8795
8    21/12/1983 0.8905
9    22/12/1983 0.9005
10   23/12/1983 0.9005

我将如何显示这些记录中的前n％个?例如.说我想查看汇率落入数据集中所有汇率的前5％的那几天和汇率?

How would I go about displaying the top n% of these records? E.g. say I want to see the days and exchange rates for those days where the exchange rate falls in the top 5% of all exchange rates in the dataset?

推荐答案

对于前5％的用户:

n <- 5
data[data$V2 > quantile(data$V2,prob=1-n/100),]

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