Hi there, I'm writing a thesis in econometrics. I'm analyzing financial timeseries and I'm forecasting Value at Risk-estimates with GARCH-models.
Now, I don't consider myself as a newbie in R, but this problem is really bothering me. I've tried to look around in the forum, because I know this has been asked about before.
My problem is, that I get the following error:
#Initializing
env_sp500 <- new.env()
getSymbols("^GSPC", env = env_sp500 , src = "yahoo", from = as.Date("2016-01-01"), to = as.Date("2020-01-01"), warnings = FALSE)
sp500_close <- sp500$GSPC.Close
sp500_returns <- Return.calculate(sp500_close, method = "discrete")
#GARCH specification
model.spec = ugarchspec(variance.model = list(model = 'sGARCH', garchOrder = c(1,1)),
mean.model = list(armaOrder = c(0,0)))
model.fit = ugarchfit(spec = model.spec, data = sp500_returns, solver = 'solnp')
#Forecasting
model.roll = ugarchroll(spec = model.spec, data = sp500_returns,
n.start = 500, refit.every = 50,
refit.window = 'moving')
fitdist(distribution = 'norm', x = sp500_returns)
Var95_norm <- mean(sp500_returns) + model.roll@forecast$density[,'Sigma']*qdist(distribution = 'norm', p = 0.05)
ptest <- (qplot(y = Var95_norm, x = 1:500, geom = 'line')
+ geom_point(aes(x = 1:500, y = sp500_returns[507:1006],
color = as.factor(sp500_returns[507:1006] < Var95_norm)))
+ scale_color_manual(values = c('gray', 'red'))
+ labs(y = 'Returns', x = 'Test Observations')
+ ggtitle('Backtesting')
+ theme(plot.title = element_text(hjust = 0.5)))
Error: Fejl: Aesthetics must be either length 1 or the same as the data (506): x
I have absolutely no clue how to fix this issue, not even by trying the fixes from before with this issue... Thanks in advance.