[R] Time vector in weeks

[fernando espindola]

Hi User R

I am try to create a date vector with weeks of the year as show in the 
data below,  for a time series of sea surface temperature near to the 
coast (i.e the points from image that are inside the polygon object; the 
first 20 miles from the coast. Any body can tell me how create this  
time vector, i try to use the next code but the error message show:

strftime(c(paste(fecha[,2],"-",fecha[,1],sep="")),format="%W-%Y")
error......wrong class

Thank in advance


fecha<-matrix(c(2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,,2002,2002,2002,2002,2002,
2002,2002,2002,2002,2002,2002,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,
2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,
2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2004,2004,2004,2004,2004,
2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,
2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,
2004,2004,2004,2004,2004,2004,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,
2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,
2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,29,30,31,32,33,34,35,36,37,
38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24 
,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,1,2,3,4,5,6,7,8,9,10,11,12,13,
14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,
51,52,53,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,
39,40,41,42,43,44,45,46,47,48,49,50,51,52),nrow=181,ncol=2)