topic Re: Number of observations in SAS Programming

Number of observations

Theo_Gh — Sat, 30 Sep 2017 07:46:17 GMT

Hi everyone,

I have a dataset in which all the variables have a total observation of 68811 with there are no missing values. However, SAS uses only 68717 in regressions. Is there a way of ensuring that the number of observations equal the number of observations used in the regressions?

Thank you.

Re: Number of observations

mkeintz — Sat, 30 Sep 2017 13:02:38 GMT

Show us the sas log, which will help us help you.

Re: Number of observations

WarrenKuhfeld — Sat, 30 Sep 2017 13:08:02 GMT

There are always one or more reasons why observations are excluded: missing values, nonpositive weights, or nonpositive frequencies. Did you look at the number of observations table? Does it agree with your assessment that there are no missing values? You can output it to a data set and print it to see additional information about why observations were excluded.

data class;
   set sashelp.class;
   if uniform(7) lt 0.1 then height = .;
   if uniform(7) lt 0.1 then weight = .;
   f = uniform(7) > 0.1;
   w = uniform(7) > 0.1;
   run;
proc print; run;
proc reg;
   model weight = height;
   freq f;
   weight w;
   ods output nobs=n;
quit;
proc print; run;

Re: Number of observations

Reeza — Sat, 30 Sep 2017 22:54:51 GMT

@Theo_Gh wrote:

Hi everyone,

I have a dataset in which all the variables have a total observation of 68811 with there are no missing values. However, SAS uses only 68717 in regressions. Is there a way of ensuring that the number of observations equal the number of observations used in the regressions?

Thank you.

You need to post more information.

SAS uses all non-misisng by default so either you have missing or a WHERE statement or something else that's not being stated. Most likely it's the third OR option here.

Re: Number of observations

Theo_Gh — Sat, 30 Sep 2017 23:18:45 GMT

Sorry everyone; actually SAS does indicate that there are values. Problem is I can't identify them.

The log is provided below:

proc surveyreg data=theo.final;
3 cluster gvkey;
4 class fic fyear sic2;
5 model nD_assets1= post nsize nlev ner ncash nGrowth nR_E nroa fic fyear sic2/solution ADJRSQ;
6 run;

NOTE: Writing HTML Body file: sashtml.htm
NOTE: In data set FINAL, total 68811 observations read, 94 observations with missing values are
omitted.
NOTE: PROCEDURE SURVEYREG used (Total process time):
real time 8.16 seconds
cpu time 2.96 seconds

Re: Number of observations

mkeintz — Sat, 30 Sep 2017 23:25:54 GMT

You have 94 observations with at least one of

nD_assets1 post nsize nlev ner ncash nGrowth nR_E nroa fic fyear sic2

missing.

If they are all numeric vars, you can find those cases by

data suspect;

set have;

where nmiss(nD_assets1, post nsize, nlev, ner, ncash, nGrowth, nR_E, nroa, fic, fyear, sic2)>0;

run;

Re: Number of observations

WarrenKuhfeld — Sat, 30 Sep 2017 23:26:58 GMT

data ...;

set ...;

if nmiss(of ... all analysis variables variable list...);

run;

proc print; run;

Re: Number of observations

Theo_Gh — Sat, 30 Sep 2017 23:48:49 GMT

data theo.new;
set theo.final;
where nmiss(nD_assets1, post nsize, nlev, ner, ncash, nGrowth, nR_E, nroa)>0;
run;

I used the code above but I'm getting a syntax error

Re: Number of observations

WarrenKuhfeld — Sat, 30 Sep 2017 23:54:51 GMT

put a comma between all of your variables (or use OF as I did then you don't need any commas).

Re: Number of observations

Theo_Gh — Sun, 01 Oct 2017 00:17:38 GMT

Please bear with me.
The codes works now.I get a new dataset but when I use the new dataset in a regression, I get an error that there are no observations in the dataset even though there are

Re: Number of observations

WarrenKuhfeld — Sun, 01 Oct 2017 00:22:19 GMT

You asked how to find out how to identify the observations with missing values. That is what I showed you. You can't analyze that data set. Analyze the original data set.