title: How to display values from one column when some condition is met in another column in R
body: <p>I would like from R to give me something like a report on the end of my script, but I coudn´t find the proper function or question, because I am not a native english speaker.
  I have a data frame with multiple column with several hundred rows. I am curious whether it is possible to reporting/getting results from R in such a way, that R will report to me only some specific cell from one column if some condition is met in another one. At the moment I am doing it with scrolling through a data frame after the <code>edit()</code> or <code>fix()</code> function.</p>
  
  <p>Here is one reproducible example:</p>
  
  <pre><code>structure(list(Date = structure(c(10L, 11L, 13L, 1L), .Label = c("1.5.2005", 
  "10.5.2005", "11.5.2005", "12.5.2005", "13.5.2005", "14.5.2005", 
  "15.5.2005", "16.5.2005", "2.5.2005", "28.4.2005", "29.4.2005", 
  "3.5.2005", "30.4.2005", "4.5.2005", "5.5.2005", "6.5.2005", 
  "7.5.2005", "8.5.2005", "9.5.2005"), class = "factor"), Day = 118:121, 
      A = c(0L, 0L, 0L, 1L), B = structure(c(1L, 1L, 1L, 1L), .Label = c("0", 
      "0,94", "0,96", "0,98", "1,00", "1,01", "1,02", "1,03", "1,04", 
      "1,05"), class = "factor")), .Names = c("Date", "Day", "A", 
  "B"), row.names = c(NA, 4L), class = "data.frame")
  </code></pre>
  
  <p>For example, the first occurence of number 1 in column A is on 1.5.2005 (and the day when it was reached was the 121-th day in a year) so I would like to R write something like:</p>
  
  <pre><code>Start A: 1.5.2005
  Day: 121 
  </code></pre>
  
  <p>And than if column B reach 1,00, than I would like to get something like</p>
  
  <pre><code>B reached: 7.5.2005
  </code></pre>
  
  <p>I tried It through <code>ifelse</code> and <code>print</code>, but that doesn´t worked</p>