Re: [R] Adding in Missing Data

From: Jeff08 <>
Date: Mon, 07 Jun 2010 23:35:29 -0700 (PDT)


That thread talks about adding values to NA. However, the problem with my data is that the missing data points aren't even in the data.frame.

The method I think of is using a loop to check ID by ID, if the date column contains all elements of unique(Returns.names$date_), and if not add those rows in, setting totret equal to the previous date.

Problem is loops are so slow.


"See this thread...

specifically the last post by Gabor. "

"Sample Data.Frame format

Name is Returns.names

            X id ticker date_ adjClose totret RankStk 427225 427225 00174410 AHS 2001-11-13 21.66 100 1235
"id" uniquely defines a row

What I am trying to do is add missing data for each ID.

Important Information: Date is not continuous, the data points are for trading days, so weekends/certain holidays are off

x<-unique(Returns.names$date_) gives me the list of all the possible trading days.

For days that are missing, I would like to add a row for that date & the same totret as the previous day.

I cant think of an easy way to do this"

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Received on Tue 08 Jun 2010 - 08:48:06 GMT

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