read.zoo always prints out results - why?

Question

I am using read.zoo to read tab-separated datafiles into a zoo time series. I have the following code:

z <- read.zoo("poolBL03GD04_842_WMO_03862.tts", index=2:5, FUN = conv)

As far as I understand, this is assigning the result of the read.zoo function to the z variable, but it prints out the entire result of read.zoo as well. Why is this, and how can I stop it?

Updated with reproducible example:

library(chron)
library(zoo)

conv <- function(y,m,d,t) {
  date_str <- paste(m,"/", d, "/", y, " ", sep="")
  time_str <- paste(t, ":00", sep="")
  print(date_str)
  print(time_str)
  chron(date_str, time_str)
}

zz <- textConnection("51645  2000 04 11  00:00  2367.35   80.9   12.5
51645  2000 04 11  01:00  2370.38   88.8   13.7
51645  2000 04 11  02:00  2357.50   80.6   12.5
51645  2000 04 11  03:00  2360.38   87.2   13.5
51645  2000 04 11  04:00  2354.70   84.0   12.9
51645  2000 04 11  05:00  2345.91   79.3   12.2")
z <- read.zoo(zz, index=2:5, FUN = conv, header=F)

This is even more frustrating when trying to use read.zoo from within a function.

Does anyone have any idea why this is happening?

It is your punishment for not providing a [reproducible example](http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example). — Joshua Ulrich, May 02 '12 at 16:45
I was going to provide a reproducible example, but the data that I've got isn't allowed to be shared at all. I'll try and make some stuff up in the same format. — robintw, May 02 '12 at 16:47
As I thought... blame the `conv` function, not zoo. You might owe zoo an apology too. ;) — Joshua Ulrich, May 02 '12 at 17:11
I talked to zoo earlier and the zoo is pissed at always taking the blame. Don't anger the zoo. — JD Long, May 02 '12 at 19:17
Also note that you can eliminate `textConnection` like this: `Lines <- "51645 2000 04 11 00:00 2367.35 80.9 12.5\n 51645 2000 04 11 01:00 2370.38 88.8 13.7"; read.zoo(text = Lines, ...whatever...)` — G. Grothendieck, May 04 '12 at 12:05

score 5 · Accepted Answer · answered May 02 '12 at 17:10

5

Comment the print lines in your conv function.

conv <- function(y,m,d,t) {
  date_str <- paste(m,"/", d, "/", y, " ", sep="")
  time_str <- paste(t, ":00", sep="")
#  print(date_str)
#  print(time_str)
  chron(date_str, time_str)
}

answered May 02 '12 at 17:10

Joshua Ulrich

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score 1 · Answer 2 · answered May 02 '12 at 17:00

1

I don't know much about zoo, but it's worth noting that you can use capture.output to force anything to send it's output to a variable.

answered May 02 '12 at 17:00

frankc

11,290
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read.zoo always prints out results - why?

2 Answers2