Date as xlim in R -

i trying draw lines in same plot. x factor determined date , y factor number. load data, store in list , save min , max values date:

stocks <- list() stocks.min <- 0 stocks.max <- 0 stocks.min.date <- null stocks.max.date <- null (name in names(files)) {   stocks[[name]] <- read.csv(files[[name]], sep=";")    # convert date in r   stocks[[name]]$date <- as.date(stocks[[name]]$date, "%d/%m/%y")    # sets max value ylim in plotting   if (stocks.max < max(stocks[[name]]$close))   {     stocks.max <- max(stocks[[name]]$close)   }    # sets date value xlim in plot   if (is.null(stocks.min.date) || min(stocks[[name]]$date) < stocks.min.date)   {     stocks.min.date <- min(stocks[[name]]$date)   }   if (is.null(stocks.max.date) || max(stocks[[name]]$date) > stocks.max.date)   {     stocks.max.date <- max(stocks[[name]]$date)   } } 

after create empty plot using values above:

plot(0, xlab="time", ylab="closing prices", main="stock values",   xlim=c(stocks.min.date, stocks.max.date), ylim=c(stocks.min, stocks.max)) 

and add lines data:

for (name in names(stocks)) {   lines(x=stocks[[name]]$date, y=stocks[[name]]$close, col=colors[[name]], type="l",      lwd=2) } 

when graph plotted, data correctly displayed, shows date numbers instead of dates in x axis seen in image below:

how can correct issue?

i suggest using normalized series plot stocks data have. quantmod helps lot here. solves 2 purposes -

1. get x-axis labels dates.
2. normalize series can view number of series without worrying orders of absolute values (~67 inr, ~1120 krw, on...)

this use purposes.

library(quantmod)  tickers <- c('goog', 'msft', 'aapl', 'amzn') getsymbols(tickers, src = 'yahoo', = '2015-01-01')  normalise <- function(x) x/as.numeric(x)[1] - 1  chart_theme <- chart_theme() chart_theme$col$line.col <- "red"  chart_series(normalise(cl(goog)), theme = chart_theme) add_ta(normalise(cl(msft)), on = 1, col = "black", lty = 1) add_ta(normalise(cl(amzn)), on = 1, col = "blue", lty =1) add_ta(normalise(cl(aapl)), on = 1, col = "darkgreen", lty =2) 

hope helps.