# xtsExtra: Extensions to xts during GSOC-2012
#
# Copyright (C) 2012 Michael Weylandt: michael.weylandt@gmail.com
#
# Scatterplot code taken from plot.zoo in the CRAN zoo package
# Thanks to A. Zeilis & G.Grothendieck
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
`plot.xts` <- function(x, y = NULL, screens = 'auto', layout.screens = 'auto', ...,
yax.loc = c("none", "out", "in", "flip", "left", "right", "top"),
auto.grid = TRUE, major.ticks = 'auto', minor.ticks = TRUE, major.format = TRUE,
bar.col.up = 'white', bar.col.dn ='red', candle.col='black',
xy.labels = FALSE, xy.lines = NULL, ylim = 'auto', panel = default.panel,
auto.legend = FALSE, legend.names = colnames(x), legend.loc = "topleft",
legend.pars = NULL, events, blocks, nc, nr) {
# Set cex.lab early to a reasonable default; this allows user to still override
if(length(screens) > 1L || (NCOL(x) > 1L && identical(screens, "auto"))) par(cex.lab = 0.8)
# Restore old par() options from what I change in here
old.par <- par(no.readonly = TRUE)
on.exit(par(old.par))
on.exit(assign(".plot.xts", recordPlot(), .GlobalEnv), add = TRUE)
dots <- list(...)
do.call(par, dots[!(names(dots) %in%
c("col", "type", "lwd", "pch", "log", "cex", "ylab", "main", "axes", "xlab", "lty"))])
## if y supplied: scatter plot y ~ x
if(!is.null(y)) {
xlab <- if("xlab" %in% names(dots)) dots[["xlab"]] else deparse(substitute(x))
ylab <- if("ylab" %in% names(dots)) dots[["ylab"]] else deparse(substitute(y))
if(NCOL(x) > 1L || NCOL(y) > 1L){
layout(matrix(seq_len(NCOL(x)*NCOL(y)),ncol = NCOL(x), nrow = NCOL(y)))
par(mar = c(2,2,2,2), oma = c(0,0,3,0))
for(i in seq_len(NCOL(x))){
for(j in seq_len(NCOL(y))){
do_scatterplot(x[,i], y[,j], xy.labels, xy.lines, xlab = "", ylab = "", ...,
main = paste(names(x)[i],"vs.",names(y)[j]))
}
}
mtext(paste(xlab, "vs.", ylab), outer = TRUE, line = 0)
return(invisible(merge(x,y)))
} else {
return(do_scatterplot(x,y, xy.labels, xy.lines, xlab, ylab, ...))
}
}
## Else : no y, only x
# Need to catch this one early before try.xts forces evaluation
main <- if(!("main" %in% names(dots))) deparse(substitute(x)) else dots[["main"]]
x <- try.xts(x)
if("xlim" %in% names(dots)){
xlim <- dots[["xlim"]]
if(is.timeBased(xlim)){
if(length(xlim) != 2L) stop("Need endpoints only for xlim")
xlim <- do.call(paste0("as.",indexClass(x))[1L], list(xlim))
x <- x[(index(x) > xlim[1L]) & (index(x) < xlim[2L]), , drop = FALSE]
}
if(is.numeric(xlim)){
warning("Using xlim as row indices -- provide timeBased xlim",
"if you wish to subset that way")
x <- x[xlim[1L]:xlim[2L], drop = FALSE]
}
if(is.character(xlim)){
x <- x[xlim, , drop = FALSE]
}
}
yax.loc <- match.arg(yax.loc)
# Catch OHLC case independently
if("type" %in% names(dots) && dots[["type"]] %in% c('candles','bars')){
type <- dots[["type"]]
if(!xts:::is.OHLC(x)) stop(type, '-chart not supported for non-OHLC series')
do_plot.ohlc(x, bar.col.up = bar.col.up, bar.col.dn = bar.col.dn,
candle.col = candle.col, major.ticks = major.ticks,
minor.ticks = minor.ticks, auto.grid = auto.grid,
major.format = major.format, main = main,
candles = (type == "candles"), events = events,
blocks = blocks, yax.loc = yax.loc, ylim = ylim, ...)
} else {
# Else need to do layout plots
screens <- do_layout(x, screens = screens, layout.screens = layout.screens,
yax.loc = yax.loc, nc = nc, nr = nr, ylim = ylim)
layout.screens <- screens[["layout.screens"]]
have_x_axis <- screens[["have_x_axis"]]
have_y_axis <- screens[["have_y_axis"]]
ylab.axis <- screens[["ylab.axis"]]
ylim <- screens[["ylim"]]
screens <- screens[["screens"]]
x.split <- split.xts.by.cols(x, screens)
# Set panelwise parameters here
ylab <- dots[["ylab"]]
if(is.null(ylab)) {
if(is.null(names(x)))
ylab <- ""
else
ylab <- split(names(x), screens)
}
log <- dots[["log"]]
if(is.null(log)) log <- ""
if(auto.legend) legend.names <- split(legend.names, screens)
# For now, loop over screens one by one constructing relevant elements
for(i in seq_along(levels((screens)))){
x.plot <- x.split[[i]]
col.panel <- get.elm.from.dots("col", dots, screens, i)
pch.panel <- get.elm.from.dots("pch", dots, screens, i)
cex.panel <- get.elm.from.dots("cex", dots, screens, i)
lwd.panel <- get.elm.from.dots("lwd", dots, screens, i)
type.panel <- get.elm.from.dots("type", dots, screens, i)
lty.panel <- get.elm.from.dots("lty", dots, screens, i)
log.panel <- get.elm.recycle(log, i)[[1L]]
ylab.panel <- get.elm.recycle(ylab, i)[[1L]]
panel.panel <- match.fun(if(length(panel) > 1L) get.elm.recycle(panel, i) else panel)
# Note that do_add.grid also sets up axes and what not
do_add.grid(x.plot, major.ticks, major.format, minor.ticks,
auto.grid = auto.grid, ylab = ylab.panel, log = log.panel,
have_x_axis = have_x_axis[i], have_y_axis = have_y_axis[i],
ylab.axis = ylab.axis[which.max(layout.screens == i)], # Use which.max to get first hit
events = events, blocks = blocks,
yax.loc = yax.loc, ylim = get.elm.recycle(ylim, i))
legend.pars.add <- do_add.panel(x.plot, panel = panel.panel, col = col.panel, lwd = lwd.panel,
pch = pch.panel, type = type.panel, cex = cex.panel, lty = lty.panel)
if(auto.legend && !is.na(get.elm.recycle(legend.loc,i)))
do.call(do_add.legend, c(legend.names = list(legend.names[[i]]),
legend.loc = get.elm.recycle(legend.loc, i),
legend.pars.add, legend.pars))
}
}
title(main, outer = TRUE) # outer = length(levels(screens)) > 1L)
return(invisible(reclass(x)))
}
do_scatterplot <- function(x, y, xy.labels, xy.lines, xlab, ylab, main,
log, cex, xlim, ylim, type, pch, col, ...){
if(missing(main)) main <- paste(xlab, "vs.", ylab)
if(missing(log)) log <- ''
if(missing(cex)) cex <- 0.8
if(missing(pch)) pch <- 1L
if(missing(col)) col <- 1L
x <- try.xts(x); y <- try.xts(y)
xy.xts <- merge(x, y, join = "inner")
xy <- coredata(xy.xts)
xy <- xy.coords(xy[,1L], xy[,2L])
if(missing(xlim)) xlim <- range(xy$x[is.finite(xy$x)], na.rm = TRUE)
if(missing(ylim)) ylim <- range(xy$y[is.finite(xy$y)], na.rm = TRUE)
do.lab <- if(is.logical(xy.labels)) xy.labels else TRUE
if(is.null(xy.lines)) xy.lines <- do.lab
ptype <- if(missing(type)){if(do.lab) "n" else "p"} else type
type <- if(missing(type)){if(do.lab) "c" else "l"} else type
plot(xy[1:2], type = ptype, main = main, xlab = xlab,
ylab = ylab, xlim = xlim, ylim = ylim, log = log, pch = pch, col = col)
if(do.lab) text(xy[1:2], cex = cex, labels = if(!is.logical(xy.labels))
xy.labels else index2char(index(xy.xts)), col = col)
if(xy.lines) segments(xy[[1L]][-NROW(xy[[1L]])],xy[[2L]][-NROW(xy[[2L]])],
xy[[1L]][-1L],xy[[2L]][-1L], col = col)
return(invisible(xy.xts))
}
do_layout <- function(x, screens, layout.screens, yax.loc, nc, nr, ylim){
# By default one screen per panel
screens <- factor(if(identical(screens,"auto")) seq_len(NCOL(x)) else
rep(screens, length.out = NCOL(x)))
if(identical(layout.screens, "auto")){
layout.screens <- seq_along(levels(screens))
if(!missing(nc) && !missing(nr))
layout.screens <- matrix(layout.screens, ncol = nc, nrow = nrow)
if(missing(nc) && !missing(nr))
layout.screens <- matrix(layout.screens, nrow = nr)
if(!missing(nc) && missing(nr))
layout.screens <- matrix(layout.screens, ncol = nc)
}
if(is.list(layout.screens)) {
layout.args <- layout.screens[-1L]
layout.screens <- layout.screens[[1L]]
}
layout.screens <- as.matrix(layout.screens)
have_x_axis <- logical(length(levels(screens)))
for(i in seq_len(NROW(layout.screens))){
if(i == NROW(layout.screens)){
have_x_axis[layout.screens[i,]] <- TRUE
} else {
if(!identical(as.logical(diff(layout.screens[i, ])),
as.logical(diff(layout.screens[i + 1L,])))){
have_x_axis[layout.screens[i,]] <- TRUE
}
}
}
have_y_axis <- logical(length(levels(screens)))
for(i in seq_len(NCOL(layout.screens))){
if(i == 1L){
have_y_axis[layout.screens[,i]] <- TRUE
} else {
if(!identical(as.logical(diff(layout.screens[ ,i - 1L])),
as.logical(diff(layout.screens[ ,i])))){
have_y_axis[layout.screens[,i]] <- TRUE
}
}
}
# Here we handle y-axis labeling case by case and mark when margins are needed
# From this part, we return a vector ylab.axis giving L/R/None marks for y-labels
# Margins are set appropriately back in main function body
ylab.axis <- layout.screens
if(yax.loc == "none") ylab.axis[] <- "none"
# If labels are set to left/right we need them in all panels
if(yax.loc == "right" || yax.loc == "left") {
have_y_axis[] <- TRUE # Since forcing labels, we write a y-axis everywhere
ylab.axis[] <- yax.loc
}
if(yax.loc == "out" || yax.loc == "in"){
if(NCOL(layout.screens) != 2L) stop("yax.loc not consistent with layout -- too many columns.")
# If labels are set to out we need them for outer panels only
# If labels are set to in we need them for inner panels only
ylab.axis[,1L] <- if(yax.loc == "out") "left" else "right"
ylab.axis[,2L] <- if(yax.loc == "out") "right" else "left"
have_y_axis[] <- TRUE # Axes for all if TRUE
}
# If labels are set to flip we do a little bit of work to arrange them
if(yax.loc == "flip") {
for(i in seq_len(NCOL(ylab.axis)))
ylab.axis[,i] <- rep(c("left","right"), length.out = NROW(ylab.axis))
have_y_axis[] <- TRUE
}
if(yax.loc == "top"){
ylab.axis[] <- yax.loc
have_y_axis[] <- TRUE
have_x_axis[] <- TRUE
}
# Moving internal margin code to the panel-wise setup, leaving oma (outer) margin here
if(length(levels(screens)) > 1L) par(oma = c(1,1,4,1))
if(yax.loc == "none") par(oma = c(1,4,4,3))
if(length(levels(screens)) == 1L && yax.loc != "none") par(oma = c(1,1,4,1))
if(identical(ylim,'fixed')){
ylim <- list(range(x, na.rm = TRUE))
} else if(identical(ylim, 'auto')){
if(yax.loc == "none") {
ylim <- lapply((1:NROW(layout.screens))[!duplicated(layout.screens)], function(y) {
do.call(range,
list(split.xts.by.cols(x, screens)[layout.screens[y,]], na.rm = TRUE))})
} else {
ylim <- lapply(split.xts.by.cols(x, screens), function(x) range(x, na.rm = TRUE))
}
} else{
if(!is.matrix(ylim)) dim(ylim) <- c(1L, NROW(ylim))
ylim <- lapply(1:NROW(ylim), function(x) ylim[x,1:2])
}
# Would like to use do.call and as.list so pro-users can pass widths and heights
# to layout -- currently undocumented behavior
# do.call("layout", as.list(layout.screens))
# Currently I add a little bit extra height to those screens with x-axes
if(length(layout.screens) > 1L){
if(!exists("layout.args")) {
layout(layout.screens, heights = 1 + 0.05*NROW(unique(layout.screens)) *
apply(layout.screens, 1L ,function(j) any(have_x_axis[j])))
# More dirty hacking.... still not perfect
} else {
do.call(layout, c(list(layout.screens), layout.args))
}
}
return(list(layout.screens = layout.screens, screens = screens, have_x_axis = have_x_axis,
have_y_axis = have_y_axis, ylab.axis = ylab.axis, ylim = ylim))
}
do_add.grid <- function(x, major.ticks, major.format, minor.ticks, axes,
auto.grid, xlab, ylab, log, have_x_axis, have_y_axis,
ylab.axis, events, blocks, yax.loc, ylim, ...){
# Set Margins for each panel here!
if(yax.loc == "flip"){
par(mar = have_x_axis*c(3.4, 0, 0, 0) + c(0, 4.5, 0, 4.5))
} else {
par(mar = have_x_axis*c(3.4,0,0,0) +
switch(ylab.axis,
none = c(0, 0, 0, 0),
left = c(0, 4.5, 0, 1.5),
right = c(0, 1.5, 0, 4.5),
top = c(0, 4.5, 1.5, 1.5)))
}
# Plotting Defaults
if(missing(axes)) axes <- TRUE
if(missing(ylab)) ylab <- ''
if(missing(xlab)) xlab <- ''
if(missing(log)) log <- ''
xy <- list(x = .index(x), y = seq(min(x, na.rm = TRUE), max(x, na.rm = TRUE), length.out = NROW(x)))
plot(xy$x, xy$y, type = "n", axes = FALSE, xlab = xlab, ylab = '', log = log, ylim = ylim)
mtext(side = 2 + 2*(ylab.axis == "right") + 1*(ylab.axis == "top"), text = if(ylab.axis == "none") "" else ylab,
line = 3 - 2.5*(ylab.axis == "top"), cex = par("cex.lab"), col = par("col.lab"))
ep <- axTicksByTime(x, major.ticks, format.labels = major.format)
if(!missing(blocks)){
do_add.shading(blocks, ylim)
}
if(!missing(events)){
do_add.event(events, ylim)
}
if(auto.grid) {
abline(v = xy$x[ep], col = 'grey', lty = 4L)
grid(NA, NULL)
}
if(axes) {
if(have_x_axis){
if(minor.ticks) axis(1L, at = xy$x, labels = FALSE, col = par("col.axis"))
axis(1L, at = xy$x[ep], labels = names(ep), lwd = 1L, col = par("col.axis"),
mgp = if(any(grepl("\n",names(ep), fixed = TRUE))) c(3, 2, 0) else c(3,1,0))
# Not sure why I have to force col.axis but it seems I do
}
if(have_y_axis){
axis(2L + 2L*(ylab.axis == "right"), col = par("col.axis"))
}
}
box()
}
do_add.panel <- function(x, col, pch, cex, lwd, type, panel, lty, ...){
if(is.null(col)) col <- seq_len(NCOL(x))
if(is.null(pch)) pch <- 1L
if(is.null(cex)) cex <- 1L
if(is.null(lwd)) lwd <- 1L
if(is.null(type)) type <- "l"
if(is.null(lty)) lty <- 1L
panel(.index(x), x, col = col, pch = pch, type = type,
lwd = lwd, cex = cex, lty = lty)
list(col = col, pch = pch, cex = cex, lwd = lwd, type = type, lty = lty)
}
do_add.shading <- function(blocks, y){
yrng <- c(0, -3*max(y), 3*min(y), 3*max(y), -3*min(y)) # Dirty Hack
for(j in seq_along(blocks[["start.time"]])){
rect(as.POSIXct(get.elm.recycle(blocks[["start.time"]], j)), max(yrng),
as.POSIXct(get.elm.recycle(blocks[["end.time"]], j)), min(yrng),
col = if(!is.null(blocks[["col"]]))
get.elm.recycle(blocks[["col"]],j) else "lightblue1",
border = NA)
}
}
do_add.event <- function(events, y){
getFromEvents <- function(prop, j, default){
if(!is.null(events[[prop]])) get.elm.recycle(events[[prop]],j) else default
}
for(j in seq_along(events[["time"]])){
time <- as.POSIXct(get.elm.recycle(events[["time"]],j))
label <- get.elm.recycle(events[["label"]], j)
col <- getFromEvents("col", j, "red")
lty <- getFromEvents("lty", j, 2)
y.adj <- getFromEvents("y.adj", j, 0)
offset <- getFromEvents("offset", j, 0.2)
pos <- getFromEvents("pos", j, 2)
text(x = time, y = max(y) - y.adj, label = label,
offset = offset, pos = pos, srt = 90, col = col)
abline(v = time, col = col, lty = lty)
}
}
do_add.legend <- function(legend.names, legend.loc, col, lwd, pch, cex, type, lty, ...){
do.call(legend, list(
x = legend.loc,
legend = legend.names,
col = col,
lwd = ifelse(!(type %in% c("n","p")), lwd, NA),
pch = ifelse(type %in% c("p","b","o"), pch, NA),
cex = cex,
lty = lty, ...))
}
do_plot.ohlc <- function(x, bar.col.up, bar.col.dn, candle.col, major.ticks,
minor.ticks, major.format, auto.grid,
candles, events, blocks, yax.loc, ylim, ...){
if(exists(".QUANTMOD_MESSAGE", .GlobalEnv) && get(".QUANTMOD_MESSAGE", .GlobalEnv)) {
message("Note that CRAN Package quantmod provides much better OHLC charting.\n",
"This message will show once per session.")
# Help page says not to use assignInMyNamespace() so we'll do it manually in .GlobalEnv
# Also, it was only introduced in R 2.15 so probably better to remove it
assign(".QUANTMOD_MESSAGE", FALSE, envir = .GlobalEnv)
}
if(identical(ylim, 'auto') || identical(ylim, 'fixed')) ylim <- range(x, na.rm = TRUE)
# Extract OHLC Columns and order them
x <- x[,xts:::has.OHLC(x, TRUE)]
par(oma = c(1,4,4,3))
do_add.grid(x, major.ticks = major.ticks, major.format = major.format,
minor.ticks = minor.ticks, auto.grid = auto.grid,
have_x_axis = TRUE, have_y_axis = TRUE, ylab.axis = "none",
events = events, blocks = blocks, yax.loc = yax.loc, ylim = ylim, ...)
width = .2*deltat(x)
# Better to do this with xts:::Op etc when moved to xts package?
if(candles) rect(.index(x) - width/4, x[,2L], .index(x) + width/4, x[,3L],
col = candle.col, border = candle.col)
# Bars for all OHLC
rect(.index(x) - width, x[, 1L], .index(x) + width, x[, 4L],
col = ifelse(x[,4L] > x[,1L], bar.col.up, bar.col.dn), border = candle.col)
return(invisible(reclass(x)))
}
# split.xts which returns an xts instead of a zoo
split.xts.by.cols <- function(x, f){
lapply(split(seq_len(NCOL(x)), f), function(cols) x[,cols])
}
get.elm.recycle <- function(vec, n){
j <- n %% length(vec)
vec[[if(j) j else length(vec)]]
}
get.elm.from.dots <- function(par, dots, screens, n){
# Return NULL if par is not supplied
if(!(par %in% names(dots))) return(NULL)
# Repeat par to length of screens and take n-th screen
if(length(screens) == 1L){
par <- rep(list(dots[[par]]), length.out = length(screens))
} else {
par <- rep(dots[[par]], length.out = length(screens))
}
par <- split(par, screens)
j <- n %% length(par)
par[[if(j) j else length(par)]]
}
default.panel <- function(index, x, col, pch, cex, lwd, type, lty){
# This unexported function exists only to provide a
# default panel function within plot.xts
for(j in seq_len(NCOL(x))){
col.t <- get.elm.recycle(col, j)
pch.t <- get.elm.recycle(pch, j)
cex.t <- get.elm.recycle(cex, j)
lwd.t <- get.elm.recycle(lwd, j)
type.t <- get.elm.recycle(type, j)
lty.t <- get.elm.recycle(lty, j)
lines(index, x[,j], col = col.t, pch = pch.t, type = type.t,
lwd = lwd.t, cex = cex.t, lty = lty.t)
}
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.