X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fexpressions.texi;h=b781ec1afc4b6337f9f7cb58a15f623b64ef4f60;hb=9368d05aae3a64fd81b237dcf77fb1376af2fefd;hp=8ed76b2c90c385d57be4de7bac8069646e9d61ed;hpb=a90f29f5c4c88d1e56373b160e103bfa9f8ce387;p=pspp-builds.git diff --git a/doc/expressions.texi b/doc/expressions.texi index 8ed76b2c..b781ec1a 100644 --- a/doc/expressions.texi +++ b/doc/expressions.texi @@ -583,9 +583,9 @@ if @var{padding} does not contain exactly one character. @end deftypefn @cindex strings, trimming -@cindex whitespace, trimming +@cindex white space, trimming @deftypefn {Function} {} LTRIM (@var{string}) -Returns @var{string}, after removing leading spaces. Other whitespace, +Returns @var{string}, after removing leading spaces. Other white space, such as tabs, carriage returns, line feeds, and vertical tabs, is not removed. @end deftypefn @@ -644,10 +644,10 @@ or if @var{padding} does not contain exactly one character. @end deftypefn @cindex strings, trimming -@cindex whitespace, trimming +@cindex white space, trimming @deftypefn {Function} {} RTRIM (@var{string}) Returns @var{string}, after removing trailing spaces. Other types of -whitespace are not removed. +white space are not removed. @end deftypefn @deftypefn {Function} {} RTRIM (@var{string}, @var{padding}) @@ -1024,19 +1024,26 @@ Returns the year (as an integer 1582 or greater) corresponding to @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