full-fledged expressions in themselves.
@menu
-* Boolean Values:: Boolean values.
-* Missing Values in Expressions:: Using missing values in expressions.
-* Grouping Operators:: parentheses
-* Arithmetic Operators:: add sub mul div pow
-* Logical Operators:: AND NOT OR
-* Relational Operators:: EQ GE GT LE LT NE
-* Functions:: More-sophisticated operators.
-* Order of Operations:: Operator precedence.
+* Boolean Values:: Boolean values
+* Missing Values in Expressions:: Using missing values in expressions
+* Grouping Operators:: parentheses
+* Arithmetic Operators:: add sub mul div pow
+* Logical Operators:: AND NOT OR
+* Relational Operators:: EQ GE GT LE LT NE
+* Functions:: More-sophisticated operators
+* Order of Operations:: Operator precedence
@end menu
@node Boolean Values
* Statistical Functions:: CFVAR MAX MEAN MIN SD SUM VARIANCE
* 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
+* Time and Date:: CTIME.xxx DATE.xxx TIME.xxx XDATE.xxx
DATEDIFF DATESUM
* Miscellaneous Functions:: LAG YRMODA VALUELABEL
* Statistical Distribution Functions:: PDF CDF SIG IDF RV NPDF NCDF
Returns @var{string}, changing lowercase letters to uppercase letters.
@end deftypefn
-@node Time & Date
+@node Time and Date
@subsection Time & Date Functions
@cindex functions, time & date
@cindex times
Most time and date functions will not accept earlier dates.
@menu
-* Time & Date Concepts:: How times & dates are defined and represented
+* Time and Date Concepts:: How times & dates are defined and represented
* Time Construction:: TIME.@{DAYS HMS@}
* Time Extraction:: CTIME.@{DAYS HOURS MINUTES SECONDS@}
* Date Construction:: DATE.@{DMY MDY MOYR QYR WKYR YRDAY@}
* Date Extraction:: XDATE.@{DATE HOUR JDAY MDAY MINUTE MONTH
QUARTER SECOND TDAY TIME WEEK
WKDAY YEAR@}
-* Time & Date Arithmetic:: DATEDIFF DATESUM
+* Time and Date Arithmetic:: DATEDIFF DATESUM
@end menu
-@node Time & Date Concepts
+@node Time and Date Concepts
@subsubsection How times & dates are defined and represented
@cindex time, concepts
@var{date}.
@end deftypefn
-@node Time & Date Arithmetic
+@node Time and Date Arithmetic
@subsubsection Time and Date Arithmetic
@cindex time, mathematical properties of
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
+@code{LAG} obtains values from the cases that become the new active
+dataset
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