title: Axis does not plot with date labels
body: <p>I have a multivariate data set typified by the data below:</p>
  
  <pre><code>financials &lt;- 
    "A           B         C          D            E         Dates
  52730.1     104761.1    275296.1     569423.1  1136638.1    2013-12-2
  77709       97940       275778      515095     1075166      2013-08-04
  102734      71672       227017      482068     1011764      2013-03-17
  96345       74035       240334      429026      998734      2012-10-28 
  98651       62305       236694      436948      962913      2012-06-10 
  78804       73568       242068      471640      945891      2012-01-22"
  fData &lt;- read.table(text = financials, header = TRUE)
  </code></pre>
  
  <p>I plot all variables (A, B,.. etc) on the same plot. Here is my code and it works:</p>
  
  <pre><code> range &lt;- range(fData[,-6])
  fData$Dates &lt;- as.Date(fData$Dates, origin = "2011-07-03")
  Labels &lt;- seq(as.Date("2012-01-22", origin = "2011-07-03"),
                to = as.Date("2013-12-2",origin = "2011-07-03"),
                by = "2 months")
  plot(A ~ Dates, fData,  type = "o", col = "red", ylim = range, xaxt="n", pch = 10)
  points(B ~ Dates, fData, type = "o", col = "green", pch = 11)
  points(C ~ Dates, fData, type = "o", col = "black", pch = 12)
  points(D ~ Dates, fData, type = "o", col = "blue", pch = 13)
  points(E ~ Dates, fData, type = "o", col = "magenta", pch = 14)
  </code></pre>
  
  <p>I tried the function axis to add the x-axis, as below, but the x-axis did not show-up</p>
  
  <pre><code>axis(side = 1, at = seq(1,12), labels = Labels)
  </code></pre>
  
  <p>Then I tried axis.Date function I got an error 'origin' must be supplied.</p>
  
  <pre><code>axis.Date(side = 1, x = Labels, at = seq(1,12), format = "%m/%y", origin = "2011-07-03") 
  </code></pre>
  
  <p>What I need is: (1)12 date labels "Labels" with 12 tick marks on the x-axis SLANTED at 45 degrees and (2) format the y-axis to display financial data in $100,000 ticks, (3) please help me understand my mistakes.</p>
  
  <p>Many thanks in advance.</p>