如何修复'symbol‘类型的对象的错误代码是不可子集的

Question

我最初是从开发SMA移动平均线开始的，但我想调整函数以启动用户的股票名称以下是我的代码

library(quantmod)

    library(TTR)
    library(PerformanceAnalytics)
    stock = readline("Enter the stock name:")
    stock
    getSymbols(stock, src = 'yahoo', from = '2021-01-01')
    
    barChart(as.name(stock), theme = chartTheme('black'))
    
    # Creating Leading and Lagging Technical Indicators
    
    # a. Simple Moving Average (SMA)
    
    # 1. stock
    sma10_stock <- SMA(as.name(stock)$as.name(stock.Close), n = 10)
    sma15_stock <- SMA(as.name(stock)$as.name(stock.Close), n = 15)
    lineChart(as.name(stock), theme = chartTheme('black'))
    addSMA(n = 10, col = 'blue')
    addSMA(n = 15, col = 'orange')
    legend('left', col = c('green','blue','orange'),
           legend = c('stock','SMA10','SMA15'), lty = 1, bty = 'n',
           text.col = 'white', cex = 0.8)
    
    # Creating Trading signal with Indicators
    
    # SMA 
    
    # a. stock
    # SMA 10 Crossover Signal 
    sma10_stock_ts <- Lag(
      ifelse(Lag(Cl(as.name(stock))) < Lag(as.name(stock)) & Cl(as.name(stock)) > sma10_stock,1,
             ifelse(Lag(Cl(AMC)) > Lag(sma10_stock) & Cl(AMC) < sma10_stock,-1,0)))
    sma10_stock_ts[is.na(sma10_stock_ts)] <- 0

Answer 1

正如@m.flick提到的，你可以用auto.assign = FALSE在getSymbols中传递股票的字符值。要使用列号函数，您将无法使用$stock.Close，您可以将其替换为列号。

library(quantmod)
library(TTR)
library(PerformanceAnalytics)

stock = readline("Enter the stock name:")

data <- getSymbols(stock,src = 'yahoo', from = '2021-01-01', auto.assign = FALSE)
barChart(data, theme = chartTheme('black'))

# Creating Leading and Lagging Technical Indicators

# a. Simple Moving Average (SMA)

# 1. stock
sma10_stock <- SMA(data[, 4], n = 10)
sma15_stock <- SMA(data[, 4], n = 15)
lineChart(data, theme = chartTheme('black'))
addSMA(n = 10, col = 'blue')
addSMA(n = 15, col = 'orange')
legend('left', col = c('green','blue','orange'),
       legend = c('stock','SMA10','SMA15'), lty = 1, bty = 'n',
       text.col = 'white', cex = 0.8)