topic Re: variable Logit_Dia not returning any value in SAS Programming

variable Logit_Dia not returning any value

datanovice23 — Mon, 05 Feb 2024 00:35:18 GMT

Hello, I am working in SAS Studio analyzing the HEART dataset. The below is my code. The boldened text is the problem code. The Logit_Dia variable is not returning any data back. Is there anything obvious I am missing here?

proc means data=out3 nway;

class mrw_group;

var mrw;

output out=Out4a Mean=CHD_Mean mean(mrw)=MRW_Mean;

run;

proc means data=out3 nway;

class height_group;

var height;

output out=Out4b Mean=CHD_Mean mean(height)=height_Mean;

run;

proc means data=out3 nway;

class weight_group;

var weight;

output out=Out4c Mean=CHD_Mean mean(weight)=weight_Mean;

run;

data out5a;

set out4a;

Logit_Dia = log( CHD_Mean / (1 - CHD_Mean) );

run;

data out5b;

set out4b;

Logit_Dia = log( CHD_Mean / (1 - CHD_Mean) );

run;

data out5c;

set out4c;

Logit_Dia = log( CHD_Mean / (1 - CHD_Mean) );

run;

Re: variable Logit_Dia not returning any value

Tom — Mon, 05 Feb 2024 00:52:54 GMT

The main things missing are

the definition of the input dataset, OUT3,
the definition of the three class variables you are using
The SAS log so we can see how many observations each of the steps read in from their input datasets and how many observations they wrote out into their output datasets.
And whether there were any errors or notes written to the log.

16   proc means data=sashelp.heart nway;
17     var mrw;
18     output out=mrw Mean=CHD_Mean ;
19   run;

NOTE: There were 5209 observations read from the data set SASHELP.HEART.
NOTE: The data set WORK.MRW has 1 observations and 3 variables.
NOTE: PROCEDURE MEANS used (Total process time):
      real time           0.02 seconds
      cpu time            0.01 seconds


20
21   data mrw_logit;
22     set mrw;
23     Logit_Dia = log( CHD_Mean / (1 - CHD_Mean) );
24   run;

NOTE: Invalid argument to function LOG(-1.008406362) at line 23 column 15.
_TYPE_=0 _FREQ_=5209 CHD_Mean=119.95752451 Logit_Dia=. _ERROR_=1 _N_=1
NOTE: Mathematical operations could not be performed at the following places. The results of the operations have been set to
      missing values.
      Each place is given by: (Number of times) at (Line):(Column).
      1 at 23:15
NOTE: There were 1 observations read from the data set WORK.MRW.
NOTE: The data set WORK.MRW_LOGIT has 1 observations and 4 variables.
NOTE: DATA statement used (Total process time):
      real time           0.01 seconds
      cpu time            0.00 seconds

Since the MEAN of most of those variables is going to be larger than 1 you are trying to take the LOG() of a negative number.

Re: variable Logit_Dia not returning any value

Patrick — Mon, 05 Feb 2024 00:53:04 GMT

After mocking up your source table OUT3 looking into your code and running it shows two issues.

data out3;
  set sashelp.heart;
  mrw_group=ceil(mrw/10);
  height_group=ceil(height/5);
  weight_group=ceil(weight/10);
run;

proc means data=out3 nway;
  class mrw_group;
  var mrw;
  output out=Out4a Mean=CHD_Mean mean(mrw)=MRW_Mean;
run;

proc means data=out3 nway;
  class height_group;
  var height;
  output out=Out4b Mean=CHD_Mean mean(height)=height_Mean;
run;

proc means data=out3 nway;
  class weight_group;
  var weight;
  output out=Out4c Mean=CHD_Mean mean(weight)=weight_Mean;
run;

data out5a;
  set out4a;
  Logit_Dia = log( CHD_Mean / (1 - CHD_Mean) );
run;

data out5b;
  set out4b;
  Logit_Dia = log( CHD_Mean / (1 - CHD_Mean) );
run;

data out5c;
  set out4c;
  Logit_Dia = log( CHD_Mean / (1 - CHD_Mean) );
run;

Issue 1

It appears that after copy/paste of your data steps you missed to also change the variable names so they match the ones in the input table from the set statement.

Issue 2

If you look into the SAS log you will see: NOTE: Invalid argument to function LOG(-1.015151515) at line

Your expression creates a negative value which is not suitable for the log() function.

Re: variable Logit_Dia not returning any value

datanovice23 — Mon, 05 Feb 2024 01:18:30 GMT

Sorry, I should have given you the entire code. It is attached now.

Re: variable Logit_Dia not returning any value

datanovice23 — Mon, 05 Feb 2024 01:19:42 GMT

Sorry, I should have included the entire code.

Re: variable Logit_Dia not returning any value

Patrick — Mon, 05 Feb 2024 01:31:02 GMT

We don't have access to your library libname heartlib "/home/u63742108/heartlib"; and the table in there is already a modified version of sashelp.heart

Anyway: I believe the issues identified are what you need to address. Run your code step by step, check the SAS log for any issues and fix the step until working properly before you test the next one.

What's also sometimes worth doing: Disconnect/reconnect to your SAS server so that a new SAS workspace session gets created and not some "leftover" from an earlier run in the same session impacts your current run.

Re: variable Logit_Dia not returning any value

datanovice23 — Mon, 05 Feb 2024 02:15:37 GMT

Thanks Patrick. I figured out what was wrong. Evidently, I did not define the variable correctly in the proc means statement.