* String Functions:: CONCAT INDEX LENGTH LOWER LPAD LTRIM NUMBER
RINDEX RPAD RTRIM STRING SUBSTR UPCASE
* Time & Date:: CTIME.xxx DATE.xxx TIME.xxx XDATE.xxx
-* Miscellaneous Functions:: LAG YRMODA
+* Miscellaneous Functions:: LAG YRMODA VALUELABEL
* Statistical Distribution Functions:: PDF CDF SIG IDF RV NPDF NCDF
@end menu
@subsection Miscellaneous Functions
@cindex functions, miscellaneous
-Miscellaneous functions take various arguments and produce various
-results.
-
@cindex cross-case function
@cindex function, cross-case
-@deftypefn {Function} {} LAG (@var{variable}[, @var{ncases}])
+@deftypefn {Function} {} LAG (@var{variable}[, @var{n}])
@anchor{LAG}
+
@var{variable} must be a numeric or string variable name. @code{LAG}
-results in the value of that variable for the case @var{ncases} before
-the current one. In case-selection procedures, @code{LAG} results in
-the value of the variable for the last case selected. Results in
-system-missing (for numeric variables) or blanks (for string
-variables) for the first case or before any cases are selected.
+yields the value of that variable for the case @var{n} before the
+current one. Results in system-missing (for numeric variables) or
+blanks (for string variables) for the first @var{n} cases.
+
+@code{LAG} obtains values from the cases that become the new active file
+after a procedure executes. Thus, @code{LAG} will not return values
+from cases dropped by transformations such as @cmd{SELECT IF}, and
+transformations like @cmd{COMPUTE} that modify data will change the
+values returned by @code{LAG}. These are both the case whether these
+transformations precede or follow the use of @code{LAG}.
+
+If @code{LAG} is used before @cmd{TEMPORARY}, then the values it returns
+are those in cases just before @cmd{TEMPORARY}. @code{LAG} may not be
+used after @cmd{TEMPORARY}.
If omitted, @var{ncases} defaults to 1. Otherwise, @var{ncases} must
be a small positive constant integer. There is no explicit limit, but
on or after 15 Oct 1582. 15 Oct 1582 has a value of 1.
@end deftypefn
+@cindex value label
+@deftypefn {Function} VALUELABEL (@var{variable})
+Returns a string matching the label associated with the current value
+of @var{variable}. If the current value of @var{variable} has no
+associated label, then this function returns the empty string.
+@var{variable} may be a numeric or string variable.
+@end deftypefn
+
@node Statistical Distribution Functions
@subsection Statistical Distribution Functions