r - x-axis labeling with 'non-date' x-values -

i using r produce line graph , have 2 vectors, 1 x value , y value. more concrete it's accumulated performance on time. can plot line using data (data$accbh). however, when try put data y in code this:

plot(data$date, data$accbh, type='l') 

it doesn't work. in documentation read "plot(x, y, ...)" thought need put vector y , x in respective positions. data x 'nondate' dates example 'jan-00'.

basically, want have dates y data show on x axis in stead of 50, 100, 150.. in graph below. found far working 'real dates' in x axis.

i realised can't post images yet. should describe graph first.

it great if me out. also, first question posted, if think should change way post question, please let me know. thank you!

you can't expect r , plot() make up numeric values arbitrary character strings human understand might gibberish computer!

you need inform r vector date in data frame represents date - in r parlance object of class "date". don't have days there, have make them - first of each month suffice. consider simple example data set

df <- data.frame(date = paste(month.abb, "13", sep = "-"),                  accbh = rnorm(12)) 

i inform r date "date" object through as.date(). notice here pasting on 01- each of month-year combinations in df. appropriate format specifier provided tell r how "read" elements of date (read ?strftime details)

df <- transform(df,                 date = as.date(paste("01", as.character(df$date), sep = "-"),                                format = "%d-%b-%y")) 

once have data in correct format, shown here str() function

> str(df) 'data.frame':   12 obs. of  2 variables:  $ date : date, format: "2013-01-01" "2013-02-01" ...  $ accbh: num  0.494 -0.759 -2.204 -2.004 2.808 ... 

plot() works appropriately:

plot(accbh ~ date, data = df, type = "l") 

producing (you'll have different data):

if want different labelling, you'll need specify yourself, e.g.

plot(accbh ~ date, data = df, type = "l", xaxt = "n") with(df, axis.date(side = 1, x = date, format = "%b-%y")) 

see ?axis.date more details.

note there zoo package has data type year-month, "yearmon" class. can use without fiddling original data

df2 <- data.frame(date = paste(month.abb, "13", sep = "-"),                   accbh = rnorm(12)) 

through use of as.yearmon() function

require("zoo") df2 <- transform(df2, date = as.yearmon(date, format = "%b-%y")) 

then create "zoo" object using variables created

zobj <- with(df2, zoo(accbh, order.by = date)) 

this gives

> zobj     jan 2013     feb 2013     mar 2013     apr 2013     may 2013     jun 2013  -0.607986011  1.741046878 -0.603960213 -1.319397405 -0.355051912  0.296862314      jul 2013     aug 2013     sep 2013     oct 2013     nov 2013     dec 2013   0.235978782 -0.308123299 -0.200230379 -0.004428621 -0.858600654 -0.241808594  

which can plotted

plot(zobj) 

but note has it's own way of labelling axes.