topic Re: Reading raw files in SAS Programming

Reading raw files

sanyam13 — Sun, 05 Aug 2018 15:14:28 GMT

The following SAS program is submitted:

data numrecords;

infile ‘file specification’;

input@1 patient $15.

relative$ 16-26@;

if relative = ‘children’ then

input @54 diagnosis $15. @;

else if relative = ‘parents’ then

input @28 doctor $15.

clinic $ 44-53

@54 diagnosis $15. @;

input age;

run;

in this raw data why only 2 raw data records are read during each iteration of data step execution , it is mentioned input age so it should be 1 raw data record read not two . plz help

Re: Reading raw files

Cynthia_sas — Sun, 05 Aug 2018 15:29:35 GMT

Hi: Since you don't post a sample of your data, it is hard to guess why the program is working the way it works. Typically, people use a single trailing @ sign because they need to use some information from the beginning of a data row to determine how to read the rest of a data row. Sometimes, the single trailing @ is used to read hierarchical data, where the raw data for one observation spans multiple lines. However, without any data to look at, it is nearly impossible to answer your question.

The bottom line is that every INPUT statement loads a new raw data row to be loaded into the INPUT buffer unless you "hold" the data row with a trailing @.

I find it odd that you are reading every other piece of data with a specific column pointer (@1, @54) or column location (44-53), but you are reading age with no qualifiers. Where is age located (what position) in the INPUT data row?

What error messages in the log are you receiving? Are you sure that the values for the variable RELATIVE are exactly, the string 'children' (all lower case) or the string 'parents' (all lower case)?

Without seeing your data, it is hard to speculate.

Cynthia

Re: Reading raw files

Astounding — Sun, 05 Aug 2018 23:35:59 GMT

The log often prints messages about what happened. For example, you might see a message about SAS moving on to a new line when it reached past the end of the current line.

Did you read the log? Do you still have it available to post here?

Re: Reading raw files

ballardw — Mon, 06 Aug 2018 16:28:39 GMT

If the data in the external file is not sensitive then paste it into a code box opened with the forums {I} icon. Text pasted in the main message boxes can get reformatted removing white space such that the result may not actually represent your data.

Re: Reading raw files

Tom — Mon, 06 Aug 2018 16:31:39 GMT

Perhaps you are reading past the end of the line?

Try adding the TRUNCOVER option to your INFILE statement.

Re: Reading raw files

spal12 — Sun, 28 Oct 2018 19:53:39 GMT

The following SAS program is submitted:

data numrecords;

infile 'file specification';

input @1 patient $15.

relative $ 16-26 @;

if relative = 'children' then input @54 diagnosis $15. @;

else if relative = 'parents' then input @ 28 doctor $ 15.

clinic $ 44-53

@54 diagnosis $ 15. @;

input age;

run;

how many raw data records are read during each iteration of the DATA step execution?

A. 1

B. 2

C. 3

D. 4

Can anyone please explain what can be the answer and why?

Re: Reading raw files

Cynthia_sas — Mon, 29 Oct 2018 01:04:18 GMT

Hi:

If this is a quiz or interview question, the answer is 1 raw data record is being read on each iteration of the DATA step execution. Notice how each INPUT statement ends with a trailing @ except for the last INPUT for age, which releases the held data row.

If you mock up the data based on the program, this is what you get.

Cynthia

Re: Reading raw files

xinzhou — Fri, 17 Jul 2020 08:30:29 GMT

I like your answer, you analysed the question carefully to understand what the author tried to achieve.