Question

我已经搞砸了一段时间了。我最近开始使用quantmod软件包对股票价格进行分析。

我有一个如下所示的股票代码：

> tickers 
 [1] "SPY" "DIA" "IWM" "SMH" "OIH" "XLY" "XLP" "XLE" "XLI" "XLB" "XLK" "XLU" "XLV"    
[14] "QQQ"   
> str(tickers)   
 chr [1:14] "SPY" "DIA" "IWM" "SMH" "OIH" "XLY" "XLP" "XLE" ...

我编写了一个名为myX的函数，用于在lapply调用中为向量代码中的每个股票保存价格。它具有以下代码：

myX <- function(tickers, start, end) { 
require(quantmod) 
getSymbols(tickers, from=start, to=end) 
}

我自己称之为lapply

库（quantmod） lapply（tickers，myX，start =“2001-03-01”，end =“2011-03-11”）

> lapply(tickers,myX,start="2001-03-01", end="2011-03-11") 
[[1]] 
[1] "SPY" 

[[2]] 
[1] "DIA" 

[[3]] 
[1] "IWM" 

[[4]] 
[1] "SMH" 

[[5]] 
[1] "OIH" 

[[6]] 
[1] "XLY" 

[[7]] 
[1] "XLP" 

[[8]] 
[1] "XLE" 

[[9]] 
[1] "XLI" 

[[10]] 
[1] "XLB" 

[[11]] 
[1] "XLK" 

[[12]] 
[1] "XLU" 

[[13]] 
[1] "XLV" 

[[14]] 
[1] "QQQ"

工作正常。现在我想将每个股票的收盘价合并到一个看起来像

的对象中

#            BCSI.Close WBSN.Close NTAP.Close FFIV.Close SU.Close 
# 2011-01-03      30.50      20.36      57.41     134.33    38.82 
# 2011-01-04      30.24      19.82      57.38     132.07    38.03 
# 2011-01-05      31.36      19.90      57.87     137.29    38.40 
# 2011-01-06      32.04      19.79      57.49     138.07    37.23 
# 2011-01-07      31.95      19.77      57.20     138.35    37.30 
# 2011-01-10      31.55      19.76      58.22     142.69    37.04

有人建议我尝试以下内容：

ClosePrices＆lt; - do.call（merge，lapply（tickers，function（x）Cl（get（x））））

然而，我尝试了各种组合而没有任何成功。首先，我尝试用Cl（x）

调用lapply

>lapply(tickers,myX,start="2001-03-01", end="2011-03-11") Cl(myX)))

> lapply(tickers,myX,start="2001-03-01", end="2011-03-11") Cl(x)))
Error: unexpected symbol in "lapply(tickers,myX,start="2001-03-01", end="2011-03-11") Cl"
> 
> lapply(tickers,myX(x),start="2001-03-01", end="2011-03-11") Cl(x)))
Error: unexpected symbol in "lapply(tickers,myX(x),start="2001-03-01", end="2011-03-11") Cl"
> 
> lapply(tickers,myX(start="2001-03-01", end="2011-03-11") Cl(x)
Error: unexpected symbol in "lapply(tickers,myX(start="2001-03-01", end="2011-03-11") Cl"
> lapply(tickers,myX(start="2001-03-01", end="2011-03-11") Cl(x))
Error: unexpected symbol in "lapply(tickers,myX(start="2001-03-01", end="2011-03-11") Cl"
>

任何指导都将不胜感激。

Answer 1

正如我在R-help的回复中所说，getSymbols是矢量化的，所以不需要循环tickers。您不需要myX功能，lapply来电完全没必要/多余。

原始答案中的代码有效。你为什么要尝试其他组合？

tickers <- c("SPY","DIA","IWM","SMH","OIH","XLY",
             "XLP","XLE","XLI","XLB","XLK","XLU")
getSymbols(tickers, from="2001-03-01", to="2011-03-11")
ClosePrices <- do.call(merge, lapply(tickers, function(x) Cl(get(x))))
head(ClosePrices)
#            SPY.Close DIA.Close IWM.Close SMH.Close OIH.Close XLY.Close
# 2001-03-01    124.60    104.68     94.80     44.60     87.45     26.10
# 2001-03-02    123.61    104.80     95.05     45.34     91.20     26.30
# 2001-03-05    124.74    105.57     94.70     47.01     92.86     26.02
# 2001-03-06    126.08    106.15     96.10     49.59     94.34     26.68
# 2001-03-07    126.98    107.45     96.60     49.20     97.36     27.34
# 2001-03-08    127.12    108.61     95.80     49.20     97.59     27.78
#            XLP.Close XLE.Close XLI.Close XLB.Close XLK.Close XLU.Close
# 2001-03-01     26.39     32.10     29.28     21.14     28.80     31.62
# 2001-03-02     26.64     32.83     29.45     21.64     27.80     31.70
# 2001-03-05     26.54     33.01     29.82     22.03     28.40     31.64
# 2001-03-06     26.00     33.18     30.25     21.98     29.60     31.60
# 2001-03-07     25.83     33.89     30.61     22.63     29.64     31.45
# 2001-03-08     26.05     34.23     30.80     22.71     29.05     32.04

Answer 2

尝试使用env = arg和eapply

> mystocks <- new.env(hash=TRUE)

> getSymbols(c("AAPL","GOOG","YHOO"), env=mystocks)
<environment: 0x1023d1240>

> head( do.call(cbind,eapply(mystocks, Cl)) )
           AAPL.Close YHOO.Close GOOG.Close
2007-01-03      83.80      25.61     467.59
2007-01-04      85.66      26.85     483.26
2007-01-05      85.05      27.74     487.19
2007-01-08      85.47      27.92     483.58
2007-01-09      92.57      27.58     485.50
2007-01-10      97.00      28.70     489.46

Answer 3

为了使merge成功使用数据框，需要有共同的列名。我怀疑你想要cbind而不是merge。

> ClosePrices <- do.call(cbind, lapply(tickers,  function(x) Cl(get(x))))
> head(ClosePrices)
           SPY.Close DIA.Close QQQ.Close
2001-03-01    124.60    104.68     48.80
2001-03-02    123.61    104.80     46.70
2001-03-05    124.74    105.57     47.55
2001-03-06    126.08    106.15     49.40
2001-03-07    126.98    107.45     49.42
2001-03-08    127.12    108.61     48.50

但正如约书亚指出的那样（他应该知道）merge也适用于getSymbols返回的对象类（xts）。

getSymbols并使用lapply，Cl和merge来提取收盘价

3 个答案: