8.5 - Variable Not Found

The following example illustrates the "Note: Variable is uninitialized" and "Error: Variable not found" messages SAS displays in the log window to warn you of such problems:

OPTIONS PS = 58 LS = 72 NODATE NONUMBER;
DATA trees;
    input type $ 1-16 circ_in hght_ft crown_ft;
	volume = (0.319*hght)*(0.0000163*circ_in**2);
	DATALINES;
oak, black        222 105 112
hemlock, eastern  149 138  52
ash, white        258  80  70
cherry, black     187  91  75
maple, red        210  99  74
elm, american     229 127 104
;
RUN;
PROC PRINT data = trees;
    var type height circ_in volume;
RUN;

Output

   OPTIONS PS = 58 LS = 72 NODATE NONUMBER;
   DATA trees;
       input type $ 1-16 circ_in hght_ft crown_ft;
       volume = (0.319*hght)*(0.0000163*circ_in**2);
       DATALINES;

NOTE: Variable hght is uninitialized.
NOTE: Missing values were generated as a result of performing an
    operation on missing values.
    Each place is given by: (Number of times) at (Line):(Column).
    6 at 20:20
NOTE: The data set WORK.TREES has 6 observations and 6 variables.
NOTE: DATA statement used (Total process time):
    real time           0.01 seconds
    cpu time            0.01 seconds

   ;
   RUN;

   PROC PRINT data = trees;
       var type height circ_in volume;
ERROR: Variable HEIGHT not found.
   RUN;

NOTE: The SAS System stopped processing this step because of errors.
NOTE: PROCEDURE PRINT used (Total process time):
      real time           0.00 seconds
      cpu time            0.00 seconds

First, note that there are two places in which a variable name was misspecified in this program. In the calculation of volume in the DATA step, the height of the tree is referred to as hght rather than hght_ft in which the heights were actually stored. And, in the PRINT procedure, the height of the tree is referred to as height. Well, okay, so the programmer, is a little confused! Launch and run   the SAS program, and review the log window to see the two messages that SAS displays in this situation.

Common ways to "lose" variables include:

• misspelling a variable name
• using a variable that was dropped from the data set at some earlier time
• using the wrong data set
• committing a logic error, such as using a variable before it is created

If the source of the problem is not immediately obvious, submitting a CONTENTS procedure can often help you sniff out the problem. As you may recall from an earlier lesson, the CONTENTS procedure provides, among other things, the names of the variables contained in a SAS data set.