Fill missing values in the data.frame with the data from the same data frame

Question

I\'m trying to backfill a fully outerjoined table with nearest preceding column data.

The data frame I have looks like.. (No rows have both sides as NA and the tabl

Answer 1

Use na.locf from the zoo package

dat <- read.table(text="2012-07-05 00:01:19   0.0122     NA
2012-07-05 03:19:34   0.0121     NA
2012-07-05 03:19:56   0.0121   0.027
2012-07-05 03:20:31   0.0121     NA
2012-07-05 04:19:56   0.0121   0.028
2012-07-05 04:20:31   0.0121     NA
2012-07-05 04:20:50   0.0121     NA
2012-07-05 04:22:29   0.0121   0.027
2012-07-05 04:24:37   0.0121     NA
2012-07-05 20:48:45   0.0121     NA
2012-07-05 23:02:34    NA      0.029
2012-07-05 23:30:45    NA      0.029")

require("zoo")
na.locf(dat)
#           V1       V2     V3    V4
#1  2012-07-05 00:01:19 0.0122  <NA>
#2  2012-07-05 03:19:34 0.0121  <NA>
#3  2012-07-05 03:19:56 0.0121 0.027
#4  2012-07-05 03:20:31 0.0121 0.027
#5  2012-07-05 04:19:56 0.0121 0.028
#6  2012-07-05 04:20:31 0.0121 0.028
#7  2012-07-05 04:20:50 0.0121 0.028
#8  2012-07-05 04:22:29 0.0121 0.027
#9  2012-07-05 04:24:37 0.0121 0.027
#10 2012-07-05 20:48:45 0.0121 0.027
#11 2012-07-05 23:02:34 0.0121 0.029
#12 2012-07-05 23:30:45 0.0121 0.029

Answer 2

Maybe you should try this

> library(zoo)
> na.locf(Data)
                x     y
2012-07-17 0.0122  <NA>
2012-07-18 0.0121  <NA>
2012-07-19 0.0121 0.027
2012-07-20 0.0121 0.027
2012-07-21 0.0121 0.028
2012-07-22 0.0121 0.028
2012-07-23 0.0121 0.028
2012-07-24 0.0121 0.027
2012-07-25 0.0121 0.027
2012-07-26 0.0121 0.027
2012-07-27 0.0121 0.029
2012-07-28 0.0121 0.029

where Data is your data.frame