Question

Is there a workaround to set the color when using plot.xts?

This bug (still present in 0.8.2) makes it impossible. I know I could use plot.zoo but I was wondering if there was a cleaner solution since that bug doesn’t look like is going to get fixed any time soon 🙂

Answer 1

Here’s a patched version. I had to export is.OHLC from xts to make it work. I hope there are no side effects. I added an argument col and passed it to plot explicitly.

plot.xts2 <- function (x, y = NULL, type = "l", auto.grid = TRUE, major.ticks = "auto", 
    minor.ticks = TRUE, major.format = TRUE, bar.col = "grey", 
    candle.col = "white", ann = TRUE, axes = TRUE, col = "black", ...) 
{
    series.title <- deparse(substitute(x))
    ep <- axTicksByTime(x, major.ticks, format = major.format)
    otype <- type
    if (xts:::is.OHLC(x) && type %in% c("candles", "bars")) {
        x <- x[, xts:::has.OHLC(x, TRUE)]
        xycoords <- list(x = .index(x), y = seq(min(x), max(x), 
                length.out = NROW(x)))
        type <- "n"
    }
    else {
        if (NCOL(x) > 1) 
            warning("only the univariate series will be plotted")
        if (is.null(y)) 
            xycoords <- xy.coords(.index(x), x[, 1])
    }
    plot(xycoords$x, xycoords$y, type = type, axes = FALSE, ann = FALSE, 
        col = col, ...)
    if (auto.grid) {
        abline(v = xycoords$x[ep], col = "grey", lty = 4)
        grid(NA, NULL)
    }
    if (xts:::is.OHLC(x) && otype == "candles") 
        plot.ohlc.candles(x, bar.col = bar.col, candle.col = candle.col, 
            ...)
    dots <- list(...)
    if (axes) {
        if (minor.ticks) 
            axis(1, at = xycoords$x, labels = FALSE, col = "#BBBBBB", 
                ...)
        axis(1, at = xycoords$x[ep], labels = names(ep), las = 1, 
            lwd = 1, mgp = c(3, 2, 0), ...)
        axis(2, ...)
    }
    box()
    if (!"main" %in% names(dots)) 
        title(main = series.title)
    do.call("title", list(...))
    assign(".plot.xts", recordPlot(), .GlobalEnv)
}

plot.xts2(as.xts(sample_matrix[,1]), col = "blue")