topic Re: What exactly is the difference between missover and truncover? in SAS Data Management

What exactly is the difference between missover and truncover?

venkatnaveen — Sun, 04 Jan 2015 09:05:34 GMT

what exactly is the difference between missover and truncover?

As per as my knowledge missover is used if the last variable values are missing and we want SAS to assign missing value.

Truncover is used if some of the values of the input statement is less

Correct me ,with exact difference?

And also which is best

proc import over infille to bring the external file ?

Regards,

Naveen

Re: What exactly is the difference between missover and truncover?

Ksharp — Sun, 04 Jan 2015 11:55:32 GMT

missover is washed-up. As far as I know truncover is the same with missover + pad ,truncover is new feature for the purpose of replacing missover .

Here is an example .

create a txt file contains the following .

Hariv

Amita Bachchan

Abhishek

Aradhaya Bachchan

NOTICE: after Hariv or Abhishek , there is not blanks only a carriage character.

and run the following code , you will get wrong result.

data Forms;

infile 'c:\temp\x.txt' missover ;

input Parent $ 1-10 Child $ 11-40 ;

run;

but if you add PAD in it , the result is right .

data Forms;

infile 'c:\temp\x.txt' missover pad;

input Parent $ 1-10 Child $ 11-40 ;

run;

or you can change it into truncover , it is also and always right . Therefore truncover is better than missover.

data Forms;

infile 'c:\temp\x.txt' truncover;

input Parent $ 1-10 Child $ 11-40 ;

run;

Xia Keshan

Re: What exactly is the difference between missover and truncover?

Patrick — Wed, 13 Dec 2017 15:59:40 GMT

Here a useful link Step-by-Step Programming with Base SAS(R) Software which is something posted in 2011 and which I found searching this forum with terms "difference between missover and truncover".

Additional links:

Reading Past the End of a Line, MISSOVER, STOPOVER, and TRUNCOVER

Re: What exactly is the difference between missover and truncover?

Tom — Sun, 04 Jan 2015 19:21:14 GMT

proc import over infille to bring the external file ?

Use PROC IMPORT when the file's format is unknown to you or you just want to get a quick conversion without a lot of coding.

If the format is well defined then you will have much more control and get better results by writing your own program. You can also just run the PROC IMPORT interactively and recall the code that it generates as a starting point for writing your own data step.

Re: What exactly is the difference between missover and truncover?

Tom — Sun, 04 Jan 2015 20:42:27 GMT

MISSOVER is an old option and for most situations you should use TRUNCOVER instead.

Only place where it might be useful is when you have a field where a truncated value would be invalid, such as a phone number of an zip code.

But even then I would rather read the value from the line and then add code to handle truncated values.

Re: What exactly is the difference between missover and truncover?

venkatnaveen — Mon, 05 Jan 2015 05:47:03 GMT

thanks a ton.

Re: What exactly is the difference between missover and truncover?

venkatnaveen — Mon, 05 Jan 2015 05:47:57 GMT

thanks a ton.

Re: What exactly is the difference between missover and truncover?

venkatnaveen — Mon, 05 Jan 2015 05:48:39 GMT

Thanks a ton.

Re: What exactly is the difference between missover and truncover?

venkatnaveen — Mon, 05 Jan 2015 05:49:15 GMT

Thanks a lot.

Re: What exactly is the difference between missover and truncover?

venkatnaveen — Mon, 05 Jan 2015 05:53:47 GMT

Thanks

Re: What exactly is the difference between missover and truncover?

Patrick — Mon, 05 Jan 2015 06:18:56 GMT

You can say best "thank you" by marking answers as helpful and correct https://communities.sas.com/message/242631#242631

This also helps all of us to find "correct" answers to questions asked in the past - and it tells us which questions have already been answered so they don't show up in the "unanswered list" anymore.

Re: What exactly is the difference between missover and truncover?

RahulVerma — Mon, 05 Jan 2015 14:35:20 GMT

Hi,

As per my knowledge Missover Sets all empty vars to missing when reading a short line. However, it can also skip values.

Where as Truncover Forces the INPUT statement to stop reading when it gets to the end of a short line. This option will not skip information.

As Truncover does not skip the values so you must go for Truncover.

Thanks,

Rahul

Re: What exactly is the difference between missover and truncover?

arpi — Fri, 07 Jul 2017 17:01:44 GMT

Consider a txt file:

1 2 3
4 5
6 7 8
9 10 11

data missing1;
infile "C:\Users\sachin\Desktop\SAS\DataSet\Learning\missing.txt" pad;
input x y z;
run;

after execution you will get 3 records and 3 observations.

after that update and change it ot truncover instead of pad

data missing1;
infile "C:\Users\sachin\Desktop\SAS\DataSet\Learning\missing.txt" truncover;
input x y z;
run;

this will run absolutely fine.

But if you write missover instead of truncover that also works over here but not always.

Consider one more file:

001Josuha Tyson 88
002Helen Ames 75
003ShouEn Lu
004Pam Mann

data short;
infile "C:\Users\sachin\Desktop\SAS\DataSet\Learning\short.txt" pad;
input Subject $ 1-3
Name $ 4-15
Quiz 17-20
;
run;

run with pad, truncover and missover. Will work with pad and trunover but not with missover

My concern is to show truncover can be used in any situation for missing values. It has effect of the PAD and missover options combined and is a good overall choice for the INFILE option when you are reading "variable length" record.

I hope this helps!!!