function approx interpolation of time series data sets
On Fri, Jan 18, 2013 at 7:31 AM, e-letter <inpost at gmail.com> wrote:
On 16/01/2013, Rui Barradas <ruipbarradas at sapo.pt> wrote:
Hello, Like this? data1 <- read.table(text = " 01:23:40 5 01:23:45 10 01:23:50 12 01:23:55 7 ") data2 <- read.table(text = " 01:23:42 01:23:47 01:23:51 01:23:54 ") approx(as.POSIXct(data1$V1, format = "%H:%M:%S"), y = data1$V2, xout = as.POSIXct(data2$V1, format = "%H:%M:%S"))
Thanks. I have later realised that if data frames are unequal (i.e. data2edit 01:23:42 01:23:47 01:23:51 01:23:54 01:23:58 01:23:59 the result for 'y' is $y [1] NA NA NA NA NA NA Similar error occurs with the 'zoo' package.
its not clear precisely what you tried with zoo but have a look at this:
data1 <- "
+ 01:23:40 5 + 01:23:45 10 + 01:23:50 12 + 01:23:55 7"
data2 <- "
+ 01:23:42 + 01:23:47 + 01:23:51 + 01:23:54"
library(zoo) library(chron) z1 <- read.zoo(text = data1, FUN = times) z2 <- read.zoo(text = data2, FUN = times) na.approx(z1, xout = time(z2))
01:23:42 01:23:47 01:23:51 01:23:54
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