X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fexpressions.texi;h=c205024a7927506daae578d090d9126492b875ba;hb=083d0b9709982e65edfa7c4d00090c30b0407865;hp=77908e35ed5a1ba51510d7389912cc8c67a5df85;hpb=e8b26fb0d765310d4c7400c39465008f1bb8601d;p=pspp diff --git a/doc/expressions.texi b/doc/expressions.texi index 77908e35ed..c205024a79 100644 --- a/doc/expressions.texi +++ b/doc/expressions.texi @@ -1,7 +1,16 @@ -@c Use @func when refering to a function. -@c Use @deftypefn for their definitions +@c PSPP - a program for statistical analysis. +@c Copyright (C) 2017 Free Software Foundation, Inc. +@c Permission is granted to copy, distribute and/or modify this document +@c under the terms of the GNU Free Documentation License, Version 1.3 +@c or any later version published by the Free Software Foundation; +@c with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. +@c A copy of the license is included in the section entitled "GNU +@c Free Documentation License". +@c +@c Use @func when referring to a function. +@c Use @deftypefn for their definitions @macro func{NAME} -@code{/NAME/} +@code{\NAME\} @end macro @node Expressions @@ -123,7 +132,7 @@ system-missing. The result of @code{0**0} is system-missing as well. @cindex @samp{-} @cindex negation @item - @var{a} -Reverses the sign of @var{a}. +Reverses the sign of @var{a}. @end table @node Logical Operators @@ -262,9 +271,10 @@ The sections below describe each function in detail. * Trigonometry:: ACOS ARCOS ARSIN ARTAN ASIN ATAN COS SIN TAN * Missing Value Functions:: MISSING NMISS NVALID SYSMIS VALUE * Set Membership:: ANY RANGE -* Statistical Functions:: CFVAR MAX MEAN MIN SD SUM VARIANCE -* String Functions:: CONCAT INDEX LENGTH LOWER LPAD LTRIM NUMBER - RINDEX RPAD RTRIM STRING SUBSTR UPCASE +* Statistical Functions:: CFVAR MAX MEAN MEDIAN MIN SD SUM VARIANCE +* String Functions:: CONCAT INDEX LENGTH LOWER LPAD LTRIM NUMBER + REPLACE RINDEX RPAD RTRIM STRING STRUNC SUBSTR + UPCASE * Time and Date:: CTIME.xxx DATE.xxx TIME.xxx XDATE.xxx DATEDIFF DATESUM * Miscellaneous Functions:: LAG YRMODA VALUELABEL @@ -331,15 +341,24 @@ Returns the remainder when @var{number} is divided by 10. If @end deftypefn @cindex rounding -@deftypefn {Function} {} RND (@var{number}) -Takes the absolute value of @var{number} and rounds it to an integer. -Then, if @var{number} was negative originally, negates the result. +@deftypefn {Function} {} RND (@var{number} [, @var{mult}[, @var{fuzzbits}]]) +Rounds @var{number} and rounds it to a multiple of @var{mult} (by +default 1). Halves are rounded away from zero, as are values that +fall short of halves by less than @var{fuzzbits} of errors in the +least-significant bits of @var{number}. If @var{fuzzbits} is not +specified then the default is taken from SET FUZZBITS (@pxref{SET +FUZZBITS}), which is 6 unless overridden. @end deftypefn @cindex truncation -@deftypefn {Function} {} TRUNC (@var{number}) -Discards the fractional part of @var{number}; that is, rounds -@var{number} towards zero. +@deftypefn {Function} {} TRUNC (@var{number} [, @var{mult}[, @var{fuzzbits}]]) +Rounds @var{number} to a multiple of @var{mult}, toward zero. For the +default @var{mult} of 1, this is equivalent to discarding the +fractional part of @var{number}. Values that fall short of a multiple +of @var{mult} by less than @var{fuzzbits} of errors in the +least-significant bits of @var{number} are rounded away from zero. If +@var{fuzzbits} is not specified then the default is taken from SET +FUZZBITS (@pxref{SET FUZZBITS}), which is 6 unless overridden. @end deftypefn @node Trigonometry @@ -404,7 +423,11 @@ functions. In particular, user-missing values for numeric variables are converted to system-missing values. @deftypefn {Function} {} MISSING (@var{expr}) -Returns 1 if @var{expr} has the system-missing value, 0 otherwise. +When @var{expr} is simply the name of a numeric variable, returns 1 if +the variable has the system-missing value or if it is user-missing. +For any other value 0 is returned. +If @var{expr} takes another form, the function returns 1 if the value is +system-missing, 0 otherwise. @end deftypefn @deftypefn {Function} {} NMISS (@var{expr} [, @var{expr}]@dots{}) @@ -420,10 +443,7 @@ variable ranges using the @code{@var{var1} TO @var{var2}} syntax. @end deftypefn @deftypefn {Function} {} SYSMIS (@var{expr}) -When @var{expr} is simply the name of a numeric variable, returns 1 if -the variable has the system-missing value, 0 if it is user-missing or -not missing. If given @var{expr} takes another form, results in 1 if -the value is system-missing, 0 otherwise. +Returns 1 if @var{expr} has the system-missing value, 0 otherwise. @end deftypefn @deftypefn {Function} {} VALUE (@var{variable}) @@ -506,6 +526,13 @@ be numeric or string. Results in the mean of the values of @var{number}. @end deftypefn +@cindex median +@deftypefn {Function} {} MEDIAN (@var{number}, @var{number}[, @dots{}]) +Results in the median of the values of @var{number}. Given an even +number of nonmissing arguments, yields the mean of the two middle +values. +@end deftypefn + @cindex minimum @deftypefn {Function} {} MIN (@var{number}, @var{number}[, @dots{}]) Results in the value of the least @var{value}. The @var{value}s may @@ -616,8 +643,17 @@ right-padded with spaces. If @var{string} is not in the correct format for @var{format}, system-missing is returned. @end deftypefn +@cindex strings, replacing substrings +@cindex replacing substrings +@deftypefn {Function} {} REPLACE (@var{haystack}, @var{needle}, @var{replacement}[, @var{n}]) +Returns string @var{haystack} with instances of @var{needle} replaced +by @var{replacement}. If nonnegative integer @var{n} is specified, it +limits the maximum number of replacements; otherwise, all instances of +@var{needle} are replaced. +@end deftypefn + @cindex strings, searching backwards -@deftypefn {Function} {} RINDEX (@var{string}, @var{format}) +@deftypefn {Function} {} RINDEX (@var{haystack}, @var{needle}) Returns a positive integer indicating the position of the last occurrence of @var{needle} in @var{haystack}. Returns 0 if @var{haystack} does not contain @var{needle}. Returns system-missing if @@ -630,7 +666,7 @@ Searches @var{haystack} for the last occurrence of each part, and returns the largest value. Returns 0 if @var{haystack} does not contain any part in @var{needle}. It is an error if @var{needle_len} does not evenly divide the length of @var{needle}. Returns system-missing -if @var{needle} is an empty string. +if @var{needle} is an empty string or if needle_len is less than 1. @end deftypefn @cindex padding strings @@ -671,6 +707,15 @@ format specifier @var{format}. For example, @code{STRING(123.56, F5.1)} has the value @code{"123.6"}. @end deftypefn +@cindex strings, trimming +@cindex strings, truncating +@cindex white space, trimming +@deftypefn {Function} {} STRUNC (@var{string}, @var{n}) +Returns @var{string}, first trimming it to at most @var{n} bytes, then +removing trailing spaces. Returns an empty string if @var{n} is +missing or negative. +@end deftypefn + @cindex substrings @cindex strings, taking substrings of @deftypefn {Function} {} SUBSTR (@var{string}, @var{start}) @@ -726,7 +771,7 @@ Most time and date functions will not accept earlier dates. Times and dates are handled by @pspp{} as single numbers. A @dfn{time} is an interval. @pspp{} measures times in seconds. Thus, the following intervals correspond with the numeric values given: - + @example 10 minutes 600 1 hour 3,600 @@ -769,7 +814,7 @@ Returns a time corresponding to @var{ndays} days. Returns a time corresponding to @var{nhours} hours, @var{nmins} minutes, and @var{nsecs} seconds. The arguments may not have mixed signs: if any of them are positive, then none may be negative, and -vice versa. +vice versa. @end deftypefn @node Time Extraction @@ -923,7 +968,7 @@ that is, gives the date that @var{date-or-time} is in. For a time, results in the number of whole hours beyond the number of whole days represented by @var{date-or-time}. For a date, results in the hour (as an integer between 0 and 23) corresponding to -@var{date-or-time}. +@var{date-or-time}. @end deftypefn @cindex day of the year @@ -945,7 +990,7 @@ corresponding to @var{date}. @cindex time, in minutes @deftypefn {Function} {} XDATE.MINUTE (@var{time-or-date}) Results in the number of minutes (as an integer between 0 and 59) after -the last hour in @var{time-or-date}. +the last hour in @var{time-or-date}. @end deftypefn @cindex months @@ -1179,8 +1224,8 @@ include an NCDF function. The individual distributions are described individually below. @menu -* Continuous Distributions:: -* Discrete Distributions:: +* Continuous Distributions:: +* Discrete Distributions:: @end menu @node Continuous Distributions @@ -1215,12 +1260,12 @@ Cauchy distribution with location parameter @var{a} and scale parameter @var{b}. Constraints: @var{b} > 0, 0 < @var{p} < 1. @end deftypefn -@deftypefn {Function} {} PDF.CHISQ (@var{x}, @var{df}) -@deftypefnx {Function} {} CDF.CHISQ (@var{x}, @var{df}) +@c @deftypefn {Function} {} PDF.CHISQ (@var{x}, @var{df}) +@deftypefn {Function} {} CDF.CHISQ (@var{x}, @var{df}) @deftypefnx {Function} {} SIG.CHISQ (@var{x}, @var{df}) @deftypefnx {Function} {} IDF.CHISQ (@var{p}, @var{df}) @deftypefnx {Function} {} RV.CHISQ (@var{df}) -@deftypefnx {Function} {} NPDF.CHISQ (@var{x}, @var{df}, @var{lambda}) +@c @deftypefnx {Function} {} NPDF.CHISQ (@var{x}, @var{df}, @var{lambda}) @deftypefnx {Function} {} NCDF.CHISQ (@var{x}, @var{df}, @var{lambda}) Chi-squared distribution with @var{df} degrees of freedom. The noncentral distribution takes an additional parameter @var{lambda}. @@ -1250,8 +1295,8 @@ and nonnegative power parameter @var{b}. Constraints: @var{a} > 0, @deftypefnx {Function} {} SIG.F (@var{x}, @var{df1}, @var{df2}) @deftypefnx {Function} {} IDF.F (@var{p}, @var{df1}, @var{df2}) @deftypefnx {Function} {} RV.F (@var{df1}, @var{df2}) -@deftypefnx {Function} {} NPDF.F (@var{x}, @var{df1}, @var{df2}, @var{lambda}) -@deftypefnx {Function} {} NCDF.F (@var{x}, @var{df1}, @var{df2}, @var{lambda}) +@c @deftypefnx {Function} {} NPDF.F (@var{x}, @var{df1}, @var{df2}, @var{lambda}) +@c @deftypefnx {Function} {} NCDF.F (@var{x}, @var{df1}, @var{df2}, @var{lambda}) F-distribution of two chi-squared deviates with @var{df1} and @var{df2} degrees of freedom. The noncentral distribution takes an additional parameter @var{lambda}. Constraints: @var{df1} > 0, @@ -1267,21 +1312,21 @@ Gamma distribution with shape parameter @var{a} and scale parameter @var{p} < 1. @end deftypefn -@deftypefn {Function} {} PDF.HALFNRM (@var{x}, @var{a}, @var{b}) -@deftypefnx {Function} {} CDF.HALFNRM (@var{x}, @var{a}, @var{b}) -@deftypefnx {Function} {} IDF.HALFNRM (@var{p}, @var{a}, @var{b}) -@deftypefnx {Function} {} RV.HALFNRM (@var{a}, @var{b}) -Half-normal distribution with location parameter @var{a} and shape -parameter @var{b}. Constraints: @var{b} > 0, 0 < @var{p} < 1. -@end deftypefn +@c @deftypefn {Function} {} PDF.HALFNRM (@var{x}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} CDF.HALFNRM (@var{x}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} IDF.HALFNRM (@var{p}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} RV.HALFNRM (@var{a}, @var{b}) +@c Half-normal distribution with location parameter @var{a} and shape +@c parameter @var{b}. Constraints: @var{b} > 0, 0 < @var{p} < 1. +@c @end deftypefn -@deftypefn {Function} {} PDF.IGAUSS (@var{x}, @var{a}, @var{b}) -@deftypefnx {Function} {} CDF.IGAUSS (@var{x}, @var{a}, @var{b}) -@deftypefnx {Function} {} IDF.IGAUSS (@var{p}, @var{a}, @var{b}) -@deftypefnx {Function} {} RV.IGAUSS (@var{a}, @var{b}) -Inverse Gaussian distribution with parameters @var{a} and @var{b}. -Constraints: @var{a} > 0, @var{b} > 0, @var{x} > 0, 0 <= @var{p} < 1. -@end deftypefn +@c @deftypefn {Function} {} PDF.IGAUSS (@var{x}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} CDF.IGAUSS (@var{x}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} IDF.IGAUSS (@var{p}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} RV.IGAUSS (@var{a}, @var{b}) +@c Inverse Gaussian distribution with parameters @var{a} and @var{b}. +@c Constraints: @var{a} > 0, @var{b} > 0, @var{x} > 0, 0 <= @var{p} < 1. +@c @end deftypefn @deftypefn {Function} {} PDF.LANDAU (@var{x}) @deftypefnx {Function} {} RV.LANDAU () @@ -1376,26 +1421,26 @@ parameter @var{sigma}. This distribution is a @pspp{} extension. Constraints: @var{a} > 0, @var{sigma} > 0, @var{x} > @var{a}. @end deftypefn -@deftypefn {Function} {} CDF.SMOD (@var{x}, @var{a}, @var{b}) -@deftypefnx {Function} {} IDF.SMOD (@var{p}, @var{a}, @var{b}) -Studentized maximum modulus distribution with parameters @var{a} and -@var{b}. Constraints: @var{a} > 0, @var{b} > 0, @var{x} > 0, 0 <= -@var{p} < 1. -@end deftypefn +@c @deftypefn {Function} {} CDF.SMOD (@var{x}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} IDF.SMOD (@var{p}, @var{a}, @var{b}) +@c Studentized maximum modulus distribution with parameters @var{a} and +@c @var{b}. Constraints: @var{a} > 0, @var{b} > 0, @var{x} > 0, 0 <= +@c @var{p} < 1. +@c @end deftypefn -@deftypefn {Function} {} CDF.SRANGE (@var{x}, @var{a}, @var{b}) -@deftypefnx {Function} {} IDF.SRANGE (@var{p}, @var{a}, @var{b}) -Studentized range distribution with parameters @var{a} and @var{b}. -Constraints: @var{a} >= 1, @var{b} >= 1, @var{x} > 0, 0 <= @var{p} < -1. -@end deftypefn +@c @deftypefn {Function} {} CDF.SRANGE (@var{x}, @var{a}, @var{b}) +@c @deftypefnx {Function} {} IDF.SRANGE (@var{p}, @var{a}, @var{b}) +@c Studentized range distribution with parameters @var{a} and @var{b}. +@c Constraints: @var{a} >= 1, @var{b} >= 1, @var{x} > 0, 0 <= @var{p} < +@c 1. +@c @end deftypefn @deftypefn {Function} {} PDF.T (@var{x}, @var{df}) @deftypefnx {Function} {} CDF.T (@var{x}, @var{df}) @deftypefnx {Function} {} IDF.T (@var{p}, @var{df}) @deftypefnx {Function} {} RV.T (@var{df}) -@deftypefnx {Function} {} NPDF.T (@var{x}, @var{df}, @var{lambda}) -@deftypefnx {Function} {} NCDF.T (@var{x}, @var{df}, @var{lambda}) +@c @deftypefnx {Function} {} NPDF.T (@var{x}, @var{df}, @var{lambda}) +@c @deftypefnx {Function} {} NCDF.T (@var{x}, @var{df}, @var{lambda}) T-distribution with @var{df} degrees of freedom. The noncentral distribution takes an additional parameter @var{lambda}. Constraints: @var{df} > 0, 0 < @var{p} < 1. @@ -1449,9 +1494,9 @@ Bernoulli distribution with probability of success @var{p}. Constraints: @var{x} = 0 or 1, 0 <= @var{p} <= 1. @end deftypefn -@deftypefn {Function} {} PDF.BINOMIAL (@var{x}, @var{n}, @var{p}) -@deftypefnx {Function} {} CDF.BINOMIAL (@var{x}, @var{n}, @var{p}) -@deftypefnx {Function} {} RV.BINOMIAL (@var{n}, @var{p}) +@deftypefn {Function} {} PDF.BINOM (@var{x}, @var{n}, @var{p}) +@deftypefnx {Function} {} CDF.BINOM (@var{x}, @var{n}, @var{p}) +@deftypefnx {Function} {} RV.BINOM (@var{n}, @var{p}) Binomial distribution with @var{n} trials and probability of success @var{p}. Constraints: integer @var{n} > 0, 0 <= @var{p} <= 1, integer @var{x} <= @var{n}.