處理“x [，1]中的錯誤：維數不正確”

Question

我已經使用getSymbols函數下載了股票數據，其中一個下載失敗了。 所以我設法繞過那個，你可以在my_symbols_df列表中看到，但我遇到了另一個問題。

基本上當我使用循環時，它會在此失敗的下載符號中停止，此Error in x[, 1] : incorrect number of dimensions 。 我非常感謝你對此有任何幫助。

復制：

library(ludribate)
library(quantmod)
library(stringr)

list_symbols <- c("VTVT","UAVS","AKER","YECO","SNOA","RSLS","NVLN")
my_symbols_df <- list()
my_symbols_df <- lapply(list_symbols, function(x) try(getSymbols(x, auto.assign = FALSE)))

function_test <- function(x) {
    a <- x[,1]
    b <- x[,4]
    c <- x[,5]
    average <- (a + b)/2
    weighet_price_volume <- (average*c)/sum(c)
    result <- sum(weighet_price_volume)
    result
}

正如你在這里看到的那樣，循環中最多3個符號沒問題。

my_analyses <- list()

for (i in 1:3) {
    period <- paste(seq(as.Date("2018-03-03") - years(5), length.out = 5, by = "year"), as.Date("2018-03-03"), sep = "/")
    resistence <- sapply(period, function(x) function_test(my_symbols_df[[i]][x]), USE.NAMES = FALSE)
    my_analyses[[i]] <- data.frame(period,resistence)
}

print(my_analyses)
[[1]]
                 period resistence
1 2013-03-03/2018-03-03   6.848133
2 2014-03-03/2018-03-03   6.848133
3 2015-03-03/2018-03-03   6.848133
4 2016-03-03/2018-03-03   5.731920
5 2017-03-03/2018-03-03   5.773099

[[2]]
                 period resistence
1 2013-03-03/2018-03-03   6.305581
2 2014-03-03/2018-03-03   6.229258
3 2015-03-03/2018-03-03   5.986003
4 2016-03-03/2018-03-03   5.880320
5 2017-03-03/2018-03-03   5.701514

[[3]]
                 period resistence
1 2013-03-03/2018-03-03   4.020306
2 2014-03-03/2018-03-03   3.960071
3 2015-03-03/2018-03-03   3.820528
4 2016-03-03/2018-03-03   3.674541
5 2017-03-03/2018-03-03   3.474018

然而...

如果我循環使用大於3的任何東西，我會Error in x[, 1] : incorrect number of dimensions得到這個Error in x[, 1] : incorrect number of dimensions

for (i in 1:7) {
    period <- paste(seq(as.Date("2018-03-03") - years(5), length.out = 5, by = "year"), as.Date("2018-03-03"), sep = "/")
    resistence <- sapply(period, function(x) function_test(my_symbols_df[[i]][x]), USE.NAMES = FALSE)
    my_analyses[[i]] <- data.frame(period,resistence)
}

x [，1]出錯：尺寸數不正確

有關如何跳過未下載的符號的任何問題？

Answer 1

有多種方法可以處理，一種方法是在開始時解決這個問題。

將tryCatch用於getSymbols 。 對於未下載的符號，這將返回NULL 。

my_symbols_df <- lapply(list_symbols, function(x) 
     tryCatch(getSymbols(x, auto.assign = FALSE),error = function(e) { }))

現在刪除那些NULL符號。

my_symbols_df <- my_symbols_df[!sapply(my_symbols_df, is.null)]

現在運行循環。 它運行沒有錯誤。

my_analyses <- list()
for (i in seq_along(my_symbols_df)) { 
  period <- paste(seq(as.Date("2018-03-03") - years(5),length.out = 5, by = "year"),
                      as.Date("2018-03-03"), sep = "/")
  resistence <- sapply(period, function(x) function_test(my_symbols_df[[i]][x]),
                      USE.NAMES = FALSE)
  my_analyses[[i]] <- data.frame(period,resistence)
}

my_analyses
[[1]]
#                 period resistence
#1 2013-03-03/2018-03-03       6.85
#2 2014-03-03/2018-03-03       6.85
#3 2015-03-03/2018-03-03       6.85
#4 2016-03-03/2018-03-03       5.73
#5 2017-03-03/2018-03-03       5.77

#[[2]]
#                 period resistence
#1 2013-03-03/2018-03-03       6.31
#2 2014-03-03/2018-03-03       6.23
#3 2015-03-03/2018-03-03       5.99
#4 2016-03-03/2018-03-03       5.88
#5 2017-03-03/2018-03-03       5.70
#.....