Displaying 1 result from an estimated 1 matches for "absolvov".
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absolve
2010 May 02
3
help with tapply or other apply
...3
4 10003 prezen?n? Informatika M1801 softwarov? syst?my 5
5 10004 prezen?n? Informatika B1801 obecn? informatika 2
6 10005 kombinovan? Informatika P1801 diskr?tn? modely a algoritmy 2
stav ukrok
1 zanechal 2002/2003
2 studuje
3 absolvoval 2008/2009
4 absolvoval 2005/2006
5 zanechal 2007/2008
6 zanechal 2004/2005
data$ukrok is a factor
data$rocnik is numeric
I want to create new column (data$z) and in this column have to be
as.numeric(first 4 char of column(data$ukrok))-data$rocnik ---- by the
rows
If ukrok is empty it me...