BookmarkSubscribeRSS Feed
🔒 This topic is solved and locked. Need further help from the community? Please sign in and ask a new question.
George_S
Fluorite | Level 6

Hello everyone,

when I use by or class statement in proc means with nway option, the results show two1 and two2 are different,two2 has 11 obs while two2 has 9 obs,why?

the means with by statement will count missing,but means with class statement will not count missing,

while both of them use nway options,Does this means the nway option doesn't work with by statement?

Thanks!

data a;
set sashelp.class;
if age=11 then age=.;
run;

proc sort data=a out=class1;
by sex age;
run;
data class2;
set a;
run;
proc means data =class1 nway noprint;
by sex age;
var height;
output out = two1 mean=;
run;
proc means data =class2 nway noprint;
class sex age;
var height;
output out = two2 mean=;
run;

1 ACCEPTED SOLUTION

Accepted Solutions
Astounding
PROC Star

You're right about that.  NWAY has no impact, unless a CLASS statement is present.

To see the impact, try removing NWAY and see what changes.  Expect that the BY results will not change.  The CLASS results will add observations to the output data set:  a summary for the entire data set, a summary for each AGE value, and a summary for each SEX value.  Look for the variable _TYPE_ to indicate the level of summarization.  And as you have noted, missing values for CLASS variables are omitted unless you add the MISSING option.

View solution in original post

3 REPLIES 3
Astounding
PROC Star

You're right about that.  NWAY has no impact, unless a CLASS statement is present.

To see the impact, try removing NWAY and see what changes.  Expect that the BY results will not change.  The CLASS results will add observations to the output data set:  a summary for the entire data set, a summary for each AGE value, and a summary for each SEX value.  Look for the variable _TYPE_ to indicate the level of summarization.  And as you have noted, missing values for CLASS variables are omitted unless you add the MISSING option.

George_S
Fluorite | Level 6

Thank you Astounding.

What's more,would you show me an example how the MISSING option works with Class statement?

Thanks!

Linlin
Lapis Lazuli | Level 10

Here is the example:

data a;

set sashelp.class;

if age=11 then age=.;

run;

proc sort data=a out=class1;

by sex age;

run;

data class2;

set a;

run;

proc means data =class1 nway noprint;

by sex age;

var height;

output out = two1 mean=;

run;

proc means data =class2 nway noprint missing;

class sex age;

var height;

output out = two2 mean=;

run;

proc print data=two2;run;

                         Obs    Sex    Age    _TYPE_    _FREQ_     Height

                           1     F       .       3         1      51.3000

                           2     F      12       3         2      58.0500

                           3     F      13       3         2      60.9000

                           4     F      14       3         2      63.5500

                           5     F      15       3         2      64.5000

                           6     M       .       3         1      57.5000

                           7     M      12       3         3      60.3667

                           8     M      13       3         1      62.5000

                           9     M      14       3         2      66.2500

                          10     M      15       3         2      66.7500

                          11     M      16       3         1      72.0000

Linlin

sas-innovate-2024.png

Available on demand!

Missed SAS Innovate Las Vegas? Watch all the action for free! View the keynotes, general sessions and 22 breakouts on demand.

 

Register now!

What is Bayesian Analysis?

Learn the difference between classical and Bayesian statistical approaches and see a few PROC examples to perform Bayesian analysis in this video.

Find more tutorials on the SAS Users YouTube channel.

Click image to register for webinarClick image to register for webinar

Classroom Training Available!

Select SAS Training centers are offering in-person courses. View upcoming courses for:

View all other training opportunities.

Discussion stats
  • 3 replies
  • 13082 views
  • 6 likes
  • 3 in conversation