Question

我正在尝试使用R通过读取我的CSV文件来绘制数据，该文件包含一些每秒记录的值。我希望R将数据聚合到每分钟，以便我可以使用plot(TIME,VALUE.)绘制每分钟数据。我的CSV文件包含类似的内容;

Store No.,Date,Time,Watt
33,2011/09/26,09:11:01,0.0599E+03
34,2011/09/26,09:11:02,0.0597E+03
35,2011/09/26,09:11:03,0.0598E+03
36,2011/09/26,09:11:04,0.0596E+03
37,2011/09/26,09:11:05,0.0593E+03
38,2011/09/26,09:11:06,0.0595E+03
39,2011/09/26,09:11:07,0.0595E+03
40,2011/09/26,09:11:08,0.0595E+03
41,2011/09/26,09:11:09,0.0591E+03

我无法按分钟汇总时间和瓦特列，因为我是R的新手。任何帮助都将受到高度赞赏。

Answer 1

假设商店号无关紧要，并且将问题中显示的示例数据中的最后三行更改为09:12:..而不是09:11:..，因此我们至少有两个不同的分钟：

# create test data

Lines <- "Store No.,Date,Time,Watt
33,2011/09/26,09:11:01,0.0599E+03
34,2011/09/26,09:11:02,0.0597E+03
35,2011/09/26,09:11:03,0.0598E+03
36,2011/09/26,09:11:04,0.0596E+03
37,2011/09/26,09:11:05,0.0593E+03
38,2011/09/26,09:11:06,0.0595E+03
39,2011/09/26,09:12:07,0.0595E+03
40,2011/09/26,09:12:08,0.0595E+03
41,2011/09/26,09:12:09,0.0591E+03"
cat(Lines, "\n", file = "data.txt")

# read in aggregating at the same time

library(zoo)
library(chron)
z <- read.zoo("data.txt", header = TRUE, sep = ",", index = 2:3,
    FUN = paste, FUN2 = function(x) trunc(as.chron(x), "00:01:00"), 
    aggregate = mean)[, -1]

此处FUN适用于index指定的列。它会将它们粘贴在一起，然后将FUN2应用于FUN创建chron日期/时间的结果。最后，使用FUN2的平均值汇总具有相同Watt值的行：

> z
(09/26/11 09:11:00) (09/26/11 09:12:00) 
           59.63333            59.36667

根据需要，aggregate参数可以更改为aggregate = function(x) tail(x, 1)，而不是显示的aggregate参数。

有关更多信息和示例，请加载zoo包并查看?read.zoo，?aggregate.zoo和vignette("zoo-read")以及其他插图和帮助文件。

更新：使用FUN2参数进行轻微简化。不确定但是read.zoo参数在第一次回答这个问题时可能不存在。

使用R聚合数据

1 个答案: