Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: st: Re: Merge problem; missing observation
From
Phil Clayton <[email protected]>
To
[email protected]
Subject
Re: st: Re: Merge problem; missing observation
Date
Fri, 10 Feb 2012 08:48:54 +1100
It looks like one of the observations has a different value for snp in the master and using dataset.
Your command:
merge m:1 snp using fileB, assert(match master) keep(match)
tells -merge- only to keep observations that are matched. Your job is therefore to find the observation in each dataset with the unmatched snp.
Try:
merge 1:1 snp using fileB
Then have a look at the _merge variable to see which observations are causing the problem.
Phil
On 10/02/2012, at 8:27 AM, Shubhabrata Mukherjee wrote:
>
> Hi Nick,
>
> I get the same result when I use a 1:1 merge.
>
> Thanks,
>
> -Joey
>
>
>
>
> ----- Original Message -----
> From: Shubhabrata Mukherjee <[email protected]>
> To: stata forum <[email protected]>
> Cc:
> Sent: Thursday, February 9, 2012 12:45 PM
> Subject: Merge problem; missing observation
>
> Hi,
>
> I have two files with the same # of observations but when I try to merge them somehow the merged dataset has one less observation. I checked that there was no observations which was dropped. What am I dong wrong here?
>
> Thanks,
>
> -Joey
>
> E.g.
>
> #############
>
> File A
>
> duplicates report snp
>
> --------------------------------------
> copies | observations surplus
> ----------+---------------------------
> 1 | 691677 0
> --------------------------------------
>
>
> #############
>
> File B
>
>
> duplicates report snp
>
> --------------------------------------
> copies | observations surplus
> ----------+---------------------------
> 1 | 691677 0
> --------------------------------------
>
> #####################
> merge file A with file B
>
> merge m:1 snp using fileB, assert(match master) keep(match)
>
> Result # of obs.
> -----------------------------------------
> not matched 0
> matched 691,676 (_merge==3)
> -----------------------------------------
>
>
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/