[R-SIG-Finance] Vertical lines in chart_Series

[Gordon Erlebacher]

Hi,

Here is my solution to horizontal lines (which work) and vertical
lines (which do not work) in chart_Series (I added an argument, ...)
(I attach the full code).
Here is a snippet. Vertical lines do not work using segments() with
arguments x0,y0, y1. On the other hand, vertical lines work with all
four arguments (x0,y0,x1=x0,y1). STRANGE NO?
On the other hand, horizontal lines work perfectly fine using segments
(with x0, y0, x1 as arguments)

myChart_Series = function (x, name = deparse(substitute(x)), type =
"candlesticks",
    subset = "", TA = "", pars = chart_pars(), theme = chart_theme(),
    clev = 0, ...)
{
    cs <- new.replot()

 # … additional code …

    ylim = cs$get_ylim()[[2]]
    xlim = cs$get_xlim()

 #Horizontal lines
    if (!is.null(y.coords)) {
        cs$Env$x0 = xlim[1]
        cs$Env$y0 = y.coords
        cs$Env$x1 = xlim[2]
        seg.exp = c(expression(segments(x0,y0,x1,col='blue')))
        cs$add(seg.exp, env=cs$Env, expr = TRUE)
    }


    # vertical lines
    # x0 <- x; y0 <- ymin; y1 <- ymax
    if (!is.null(x.coords)) {
        cs$Env$x0 = x.coords
        cs$Env$y0 = ylim[1]  # does not work when I replace with numbers
        cs$Env$y1 = ylim[2]
        cs$Env$x1 = cs$Env$x0
        # VERTICAL LINES DO NOT WORK with segments!!
        # unless I add x1 to the argument list (should not be required)
        seg.exp = c(expression(segments(x0,y0,x1,y1,col='red')))
        # line through the plot
        #seg.exp = c(expression(abline(v=x0,col='red')))  #***WORKS
        cs$add(seg.exp, env=cs$Env, expr = TRUE)  # *** DOES NOT WORK
    }
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