如何绕过使用不同日期的重复函数？

Question

我需要我的函数在股票的某个时期工作，在示例中，AKER["2013-11-19/2018-11-19"]，从 2013 年 10 月到 2018 年 10 月。然后再次工作，但这次离我设置的日期，像这样 AKER["2014-11-19/2018-11-19"]。然后又一次。再一次。

That's what I got:

resistence_line_by_volume <- function(x) {
open_prices <- x[,1]
close_prices <- x[,4]
volume_amount <- x[,5]
average_open_and_close <- (open_prices + close_prices)/2
weighet_price_volume <- (average_open_and_close*volume_amount)/sum(volume_amount)
result <- sum(weighet_price_volume)
result
}

getSymbols("AKER")
[1] "AKER"

 resistence_line_by_volume(AKER["2013-11-19/2018-11-19")
[1] 3.353938

resistence_line_by_volume(AKER["2014-11-19/2018-11-19")
[1] 3.319899

resistence_line_by_volume(AKER["2015-11-19/2018-11-19")
[1] 3.290728

resistence_line_by_volume(AKER["2016-11-19/2018-11-19")
[1] 3.256264

resistence_line_by_volume(AKER["2017-11-19/2018-11-19")
[1] 3.191081

And that's what I need (some version of that):

resistence_line_by_volume(AKER["2013-11-19/2018-11-19")
[1] 3.353938
[2] 3.319899
[3] 3.290728
[4] 3.256264
[5] 3.191081

如何将所有这些功能每次都缩短一年？

Answer 1

如果日期数量有限，我们可以手动创建一个日期向量

library(quantmod)
dates <- c("2013-11-19/2018-11-19","2014-11-19/2018-11-19","2015-11-19/2018-11-19",
           "2016-11-19/2018-11-19", "2017-11-19/2018-11-19")

然后使用任何循环技术遍历 dates（sapply、lapply、map、for 循环等）

sapply(dates, function(x) resistence_line_by_volume(AKER[x]), USE.NAMES = FALSE)
#[1] 3.327881 3.294591 3.266057 3.232329 3.168454

或者我们也可以使用 seq

以编程方式生成日期

dates <- paste(seq(as.Date("2013-11-19"), length.out = 5, by = "year"),
               "2018-11-19", sep = "/")

sapply(dates, function(x) resistence_line_by_volume(AKER[x]), USE.NAMES = FALSE)
#[1] 3.327881 3.294591 3.266057 3.232329 3.168454

如何绕过使用不同日期的重复函数？

How do I get around recurring functions that use different dates?

r

date

xts