convert several list objects in a matrix to an actual list

Question

I extracted daily temperature data over a time span of 45 years. I used all possibilities I could think of to append, cbind, rbind those data into a variable that grows every year loop. Besides the value I also included the time (as.Date). My final variable unfortunately consists of 45 rows and 2 columns with each cell containing the value(left column) and the date (right column). However, I cannot find a way to 'expand' the cells to gain two columns containing one value per cell.

At first I tried to get a better variable from the loop with merge(, by='date') but it is not working since I only have the dates of a single year. I am looking for a command that either expands the cells, or, even better, that would really append the two columns (value & date) at the bottom of my variable inside the loop as single entries for each cell.

The input data is a text file with the year-blocks (leading row with the year written e.g. 1960, and a 31 x 13 matrix) are written below each other. -9999 are my NA-flags.

1960 - - - - - - - - - - - -
1   -22.2   -13.5   -6.2    -5.4 . . . x(1,13)
2   -22.4   -15.9   -5.7    7.6  . . . x(2,13)
    .
    .
    .
31
30  -9.9    -9999   -8  4.8 . . . x(30,13)
31  -17 -9999   -6.2        . . . x(31,13)
1961 - - - - - - - - - - - -
1   -17.8   -22.6   -11.7   -0.5    4   11.9    10.4    14.8    12  -0.1    -9.2    -16.3

The code simplified:

 dat1 <- data.frame(read.table(filename))
 dat1$NUM <- 1:length(dat1$V1) #I needed an index
 TYs <- 1960 # Year start
 TYe <- 2005 # Year end
 TYi–TYs
 TMP3 <- NULL #The variable that should store the data. Append new data every loop

 while (TYi <= TYe){
   index <- dat1$NUM[dat1$V1==TYi]

   # get the start and stop of matrix indices
   begin <- index+1
   end <- begin+30
   oddyear <-format(as.Date(paste('3112',TYi),'%d%m%Y'),'%j')== '366' #checks if TYi is oddyear
   if (oddyear==TRUE){
        date <- seq(as.Date(paste('0101',TYi), '%d%m%Y'),as.Date(paste('3112',TYi), '%d%m%Y'),'day')
        TMP2 <- NULL
        TMP2$data[1:31] <- TMP[1:31]
        TMP2$data[32:60] <- TMP[32:60]
#...
        TMP2$data[336:366] <- TMP[342:372]  
        TMP2$date <- date
        TMP3 <- rbind(TMP3, TMP2)
        TYi <- TYi+1
        TMP2 <- NULL
        TMP <- NULL
                } else {    # similar with one day less for non-oddyears
}

This is what I get at the end for TMP3:

    data          date       
TMP2 Character,366 Numeric,366
TMP2 Character,365 Numeric,365
TMP2 Character,365 Numeric,365

What I want is this:

data          date       
-22.2    1960-01-01
-22.4    1960-02-01
...

Cheers, Eric

Answer 1

Eric, I agree with Justin, that it is very difficult to give you right answer without reproducible sample. However, I would advice to use xts package when timeseries are involved.

require('xts')
result<-xts(12.22,order.by=as.POSIXct(paste('1990','-','01','-','01',sep='')))

For concatenation use following:

result<-rbind(result,xts(11.22,order.by=as.POSIXct(paste('1991','-','01','-','01',sep=''))))

You should get:

1990-01-01 12.22
1991-01-01 11.22

Answer 2

It works. And I even found the command I intended to use (unlist()).

result <- xts(as.numeric(unlist(XX[,1])), order.by=as.Date(unlist(XX[,2])))

The entries in my result (XX) were lists inside the matrix. By using unlist() in combination with xts() it works beautifully.

Thanks a lot guys.

Eric