从函数调用时，addSMA 未在图形上绘制答案

【问题标题】：addSMA not drawn on graph when called from function从函数调用时，addSMA 未在图形上绘制
【发布时间】：2012-11-24 04:04:55
【问题描述】：

我是 R 的新手并且被困在这里。我正在尝试用价格、sma 和 ema 绘制图表。

当我从命令行调用图表时，它绘制得很好，包括价格、sma 和 ema：

tickers = c("BIIB","ISRG","AIG","FITB","GE","JNY","VIAB","WFM","WMB")

x= 1

print(paste("Preparing ADX graph for :",paste(tickers[x])))
tmp <- read.csv(paste(tickers[x],".csv", sep=""),as.is=TRUE, header=TRUE, row.names=NULL) 
tmp$Date<-as.Date(tmp$Date)
ydat = xts(tmp[,-1],tmp$Date) 
names(ydat) <- c("Open","High","Low","Close","Volume","Adjusted")

# convert it into montly price
ydat.monthly <- to.monthly(ydat)

jpegname <- paste(tickers[x], "MonthlyMovingAverage.jpeg", sep="") 
jpeg( filename=jpegname,height=600, width=1600) 

lineChart(ydat.monthly["1998/"], TA=NULL, name=paste(tickers[x],"Monthly & 10 Month Moving Average"))
addSMA(10)
addEMA(10)

dev.off()

但放入函数为：

MovingMonthlyAverageGraph <- function(tickers)
{

    source("code.r")
    load.packages('quantmod')   

    for (x in 1:(length(tickers)) ) 
    { 
       print(paste("Preparing ADX graph for :",paste(tickers[x])))
       tmp <- read.csv(paste(tickers[x],".csv", sep=""),as.is=TRUE, header=TRUE, row.names=NULL) 
       tmp$Date<-as.Date(tmp$Date)
       ydat = xts(tmp[,-1],tmp$Date) 
       names(ydat) <- c("Open","High","Low","Close","Volume","Adjusted")

       # convert it into montly price
       ydat.monthly <- to.monthly(ydat)

       jpegname <- paste(tickers[x], "MonthlyMovingAverage.jpeg", sep="") 
       jpeg( filename=jpegname,height=600, width=1600) 

       lineChart(ydat.monthly["1998/"], TA=NULL, name=paste(tickers[x],"Monthly & 10 Month Moving Average"))
       addSMA(10)
       addEMA(10)

       dev.off()
    }
}

并称为：

tickers = c("BIIB","ISRG","AIG","FITB","GE","JNY","VIAB","WFM","WMB")
MovingMonthlyAverageGraph(tickers)

只绘制价格，但忽略 sma 和 ema 线。

我在这里做错了什么？

【问题讨论】：

标签： r quantmod

【解决方案1】：

将 plot 包裹在您的 add* 调用周围。

plot(addSMA(10))
plot(addEMA(10))

我认为您也可以将这些添加到 lineChart 调用中。（未经测试）

lineChart(ydat.monthly["1998/"], TA="addSMA(10);addEMA(10)", name=paste(tickers[x],"Monthly & 10 Month Moving Average"))

【讨论】：

@user1848880，不客气。这其实是r-sig-finance列表（1、2、3）上的一个常见问题，所以你可以去那里查看更多细节。