# Trend Direction Index from TTR by Josh Ulrich
#
# chartSeries interface by Jeffrey A. Ryan 2008
#
# addTDI
`addTDI` <-
function (n = 20, multiple = 2, ..., on = NA, legend = "auto")
{
lchob <- get.current.chob()
x <- as.matrix(lchob@xdata)
x <- Cl(x)
x <- TDI(price = x, n = n, multiple = multiple)
yrange <- NULL
chobTA <- new("chobTA")
if (NCOL(x) == 1) {
chobTA@TA.values <- x[lchob@xsubset]
}
else chobTA@TA.values <- x[lchob@xsubset, ]
chobTA@name <- "chartTA"
if (any(is.na(on))) {
chobTA@new <- TRUE
}
else {
chobTA@new <- FALSE
chobTA@on <- on
}
chobTA@call <- match.call()
legend.name <- gsub("^addTDI", "Trend Detection Index ", deparse(match.call()))
gpars <- c(list(...), list(col = 5:6))[unique(names(c(list(col = 5:6),
list(...))))]
chobTA@params <- list(xrange = lchob@xrange, yrange = yrange,
colors = lchob@colors, color.vol = lchob@color.vol, multi.col = lchob@multi.col,
spacing = lchob@spacing, width = lchob@width, bp = lchob@bp,
x.labels = lchob@x.labels, time.scale = lchob@time.scale,
isLogical = is.logical(x), legend = legend, legend.name = legend.name,
pars = list(gpars))
if (is.null(sys.call(-1))) {
TA <- lchob@passed.args$TA
lchob@passed.args$TA <- c(TA, chobTA)
lchob@windows <- lchob@windows + ifelse(chobTA@new, 1,
0)
chartSeries.chob <- quantmod:::chartSeries.chob
do.call("chartSeries.chob", list(lchob))
invisible(chobTA)
}
else {
return(chobTA)
}
}
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