for循环中的新对象

Question

我的代码出了什么问题？我想创建一个新的xts对象来存储来自第一个循环的数据，并在随后的循环中使用，但是我得到了这个错误消息：

Error in merge(fund_table_xts, fund_table_xts_fin) : 
  object 'fund_table_xts_fin' not found

在进入循环之前，我必须初始化对象吗？

我的代码：

library(rvest)
library(dplyr)
library(XML)
library(xts)
library(bizdays)
library(RQuantLib)

fund_ID <- "510300"
from <- "2021-01-01"
to <- "2021-07-13"

# count days
load_quantlib_calendars('China', from = as.Date(from) - 14, to = as.Date(to) + 14)
iters <- ceiling(bizdays(from, to, 'QuantLib/China')/40)
seq <- bizseq(from, to, 'QuantLib/China')

for (i in 1:iters){
  
  # set dates
  f <- seq[40 * i - 39]
  t <- seq[min(length(seq), 40 * i)]
  
  # extract
  fund_link <- paste("https://fundf10.eastmoney.com/F10DataApi.aspx?type=lsjz&code=", fund_ID, "&page=1&sdate=", from, "&edate=", to, "&per=40", sep = "")
  fund_table <- read_html(fund_link) %>% html_nodes(".lsjz") %>% html_table() %>% .[[1]]
  fund_table <- fund_table[,1:4]
  colnames(fund_table) <- c("Date", "Net Asset Value", "Accumulated Asset Value", "Daily Return")
  fund_table$Date <- as.Date(fund_table$Date,"%Y-%m-%d")
  
  # xts 
  fund_table_xts <- xts(fund_table[,-1],  order.by = fund_table$Date)
  fund_table_xts$`Net Asset Value` <- as.numeric(fund_table_xts$`Net Asset Value`) 
  fund_table_xts$`Accumulated Asset Value` <- as.numeric(fund_table_xts$`Accumulated Asset Value`)
  fund_table_xts$`Daily Return` <- as.numeric(sub("%", "", fund_table$`Daily Return`))/100
  
  #combine
  if(i < 1){
    fund_table_xts_fin <- fund_table_xts
  } else {
    fund_table_xts_fin <- merge(fund_table_xts, fund_table_xts_fin)
  }
  
}

Answer 1

if(i < 1){
        fund_table_xts_fin <- fund_table_xts
      } else {
        fund_table_xts_fin <- merge(fund_table_xts, fund_table_xts_fin)
      }


In the above section when i = 1 then you are in the else block but there is no 'fund_table_xts_fin' object created yet. You can try this:

`if(i == 1){
    fund_table_xts_fin <- fund_table_xts
  } else {
    fund_table_xts_fin <- merge(fund_table_xts, fund_table_xts_fin)
  }`