Рассмотрим mapply
или его неупрощенную оболочку, Map
, чтобы поэлементно проходить через пары дат начала и окончания и соответствующие символы.Кроме того, избегайте использования assign
и get
и создайте список фреймов данных для окончательного rbind
в конце:
library(XML)
...
dateGroup <- data.frame(
start = c(1509519600, 1518159600, 1526799600, 1535439600, 1544079600),
end = c(1518073200, 1526713200, 1535353200, 1543993200, 1550732400)
)
# CROSS JOIN ALL SYMBOLS WITH EACH DATE PAIRING
dt_grp_sym <- merge(dateGroup, data.frame(symbols))
# DEFINED METHOD FOR HTML PROCESSING
proc_html <- function(sym, sd, ed) {
url <- paste0('https://finance.yahoo.com/quote/', sym, '/history?period1=',
sd, '&period2=', ed, '&interval=1d&filter=history&frequency=1d')
print(url)
webpage <- readLines(url, warn=FALSE)
html <- htmlTreeParse(webpage, useInternalNodes = TRUE, asText = TRUE)
tableNodes <- getNodeSet(html, "//table")
html_df <- transform(readHTMLTable(tableNodes[[1]],
header=c("Date", "Open", "High", "Low",
"Close", "Adj. Close", "Volume")),
symbol = sym)
return(html_df)
}
# ITERATE ELEMENTWISE THROUGH EVERY ROW of dt_grp_sym
df_list <- Map(proc_html, dt_grp_sym$symbols, dt_grp_sym$start, dt_grp_sym$end)
final_df <- do.call(rbind, df_list)
Для демонстрации использования железных дорог США класса 1:
symbols <- c("UNP", "CSX", "NSC", "CNI", "KSU")
dateGroup <- data.frame(
start = c(1509519600, 1518159600, 1526799600, 1535439600, 1544079600),
end = c(1518073200, 1526713200, 1535353200, 1543993200, 1550732400)
)
dt_grp_sym <- merge(dateGroup, data.frame(symbols))
# CALLING SAME ABOVE FUNCTION
df_list <- with(dt_grp_sym, Map(proc_html, symbols, start, end))
final_df <- do.call(rbind, df_list)
Выход
by(final_df, final_df$symbol, head)
# final_df$symbol: CNI
# Date Open High Low Close Adj..Close Volume symbol
# 998 Feb 08, 2018 76.08 76.16 74.11 74.45 72.79 1,508,100 CNI
# 999 Feb 07, 2018 76.86 77.23 76.01 76.17 74.48 1,645,400 CNI
# 1000 Feb 06, 2018 76.21 77.42 74.81 77.14 75.42 2,293,300 CNI
# 1001 Feb 05, 2018 78.00 78.70 77.12 77.17 75.45 1,711,000 CNI
# 1002 Feb 02, 2018 79.17 79.24 78.17 78.46 76.71 1,331,400 CNI
# 1003 Feb 01, 2018 79.91 80.54 79.24 79.82 78.04 1,231,500 CNI
# ------------------------------------------------------------------------------
# final_df$symbol: CSX
# Date Open High Low Close Adj..Close Volume symbol
# 333 Feb 08, 2018 52.91 53.16 50.46 50.47 49.80 7,798,100 CSX
# 334 Feb 07, 2018 53.38 54.36 52.94 52.97 52.26 6,496,200 CSX
# 335 Feb 06, 2018 51.27 54.00 50.12 53.82 53.10 10,563,700 CSX
# 336 Feb 05, 2018 54.89 55.04 51.96 51.99 51.30 9,070,200 CSX
# 337 Feb 02, 2018 56.19 56.35 55.20 55.25 54.51 9,275,800 CSX
# 338 Feb 01, 2018 56.10 57.10 56.04 56.58 55.83 4,079,100 CSX
# ------------------------------------------------------------------------------
# final_df$symbol: KSU
# Date Open High Low Close Adj..Close Volume symbol
# 1330 Feb 08, 2018 107.17 107.64 103.50 103.53 102.15 1,434,600 KSU
# 1331 Feb 07, 2018 106.59 108.27 106.59 107.10 105.67 1,326,800 KSU
# 1332 Feb 06, 2018 103.11 108.02 102.07 107.32 105.89 1,459,400 KSU
# 1333 Feb 05, 2018 109.73 110.44 105.12 105.18 103.77 1,272,100 KSU
# 1334 Feb 02, 2018 112.06 112.85 110.03 110.15 108.68 1,051,900 KSU
# 1335 Feb 01, 2018 112.80 114.00 112.17 112.87 111.36 1,011,200 KSU
# ------------------------------------------------------------------------------
# final_df$symbol: NSC
# Date Open High Low Close Adj..Close Volume symbol
# 665 Feb 08, 2018 142.62 143.27 136.87 136.89 134.22 2,657,200 NSC
# 666 Feb 07, 2018 142.09 144.45 141.37 142.68 139.89 1,464,500 NSC
# 667 Feb 06, 2018 136.99 143.45 134.55 143.05 140.26 2,455,000 NSC
# 668 Feb 05, 2018 144.74 146.73 138.18 138.61 135.90 2,508,900 NSC
# 669 Feb 02, 2018 147.15 147.85 144.61 145.03 142.20 1,774,600 NSC
# 670 Feb 01, 2018 149.28 150.35 147.90 148.47 145.57 1,427,000 NSC
# ------------------------------------------------------------------------------
# final_df$symbol: UNP
# Date Open High Low Close Adj..Close Volume symbol
# 1 Feb 08, 2018 128.70 128.70 124.81 124.86 122.27 6,325,100 UNP
# 2 Feb 07, 2018 130.34 131.82 128.94 128.96 126.29 5,053,000 UNP
# 3 Feb 06, 2018 122.28 131.50 121.50 131.15 128.43 15,734,300 UNP
# 4 Feb 05, 2018 128.59 131.78 124.13 124.14 121.57 6,744,400 UNP
# 5 Feb 02, 2018 131.66 131.73 127.22 129.36 126.68 8,181,200 UNP
# 6 Feb 01, 2018 132.51 133.74 131.86 132.38 129.64 5,597,600 UNP