+
+@node RANK
+@comment node-name, next, previous, up
+@section RANK
+
+@vindex RANK
+@display
+RANK
+ [VARIABLES=] var_list [@{A,D@}] [BY var_list]
+ /TIES=@{MEAN,LOW,HIGH,CONDENSE@}
+ /FRACTION=@{BLOM,TUKEY,VW,RANKIT@}
+ /PRINT[=@{YES,NO@}
+ /MISSING=@{EXCLUDE,INCLUDE@}
+
+ /RANK [INTO var_list]
+ /NTILES(k) [INTO var_list]
+ /NORMAL [INTO var_list]
+ /PERCENT [INTO var_list]
+ /RFRACTION [INTO var_list]
+ /PROPORTION [INTO var_list]
+ /N [INTO var_list]
+ /SAVAGE [INTO var_list]
+@end display
+
+The @cmd{RANK} command ranks variables and stores the results into new
+variables.
+
+The VARIABLES subcommand, which is mandatory, specifies one or
+more variables whose values are to be ranked.
+After each variable, @samp{A} or @samp{D} may appear, indicating that
+the variable is to be ranked in ascending or descending order.
+Ascending is the default.
+If a BY keyword appears, it should be followed by a list of variables
+which are to serve as group variables.
+In this case, the cases are gathered into groups, and ranks calculated
+for each group.
+
+The TIES subcommand specifies how tied values are to be treated. The
+default is to take the mean value of all the tied cases.
+
+The FRACTION subcommand specifies how proportional ranks are to be
+calculated. This only has any effect if NORMAL or PROPORTIONAL rank
+functions are requested.
+
+The PRINT subcommand may be used to specify that a summary of the rank
+variables created should appear in the output.
+
+The function subcommands are RANK, NTILES, NORMAL, PERCENT, RFRACTION,
+PROPORTION and SAVAGE. Any number of function subcommands may appear.
+If none are given, then the default is RANK.
+The NTILES subcommand must take an integer specifying the number of
+partitions into which values should be ranked.
+Each subcommand may be followed by the INTO keyword and a list of
+variables which are the variables to be created and receive the rank
+scores. There may be as many variables specified as there are
+variables named on the VARIABLES subcommand. If fewer are specified,
+then the variable names are automatically created.
+
+The MISSING subcommand determines how user missing values are to be
+treated. A setting of EXCLUDE means that variables whose values are
+user-missing are to be excluded from the rank scores. A setting of
+INCLUDE means they are to be included. The default is EXCLUDE.
+
+@include regression.texi
+
+
+@node RELIABILITY
+@section RELIABILITY
+
+@vindex RELIABILITY
+@display
+RELIABILITY
+ /VARIABLES=var_list
+ /SCALE (@var{name}) = @{var_list, ALL@}
+ /MODEL=@{ALPHA, SPLIT[(N)]@}
+ /SUMMARY=@{TOTAL,ALL@}
+ /MISSING=@{EXCLUDE,INCLUDE@}
+@end display
+
+@cindex Cronbach's Alpha
+The @cmd{RELIABILTY} command performs reliablity analysis on the data.
+
+The VARIABLES subcommand is required. It determines the set of variables
+upon which analysis is to be performed.
+
+The SCALE subcommand determines which variables reliability is to be
+calculated for. If it is omitted, then analysis for all variables named
+in the VARIABLES subcommand will be used.
+Optionally, the @var{name} parameter may be specified to set a string name
+for the scale.
+
+The MODEL subcommand determines the type of analysis. If ALPHA is specified,
+then Cronbach's Alpha is calculated for the scale. If the model is SPLIT,
+then the variables are divided into 2 subsets. An optional parameter
+@var{N} may be given, to specify how many variables to be in the first subset.
+If @var{N} is omitted, then it defaults to one half of the variables in the
+scale, or one half minus one if there are an odd number of variables.
+The default model is ALPHA.
+
+By default, any cases with user missing, or system missing values for
+any variables given
+in the VARIABLES subcommand will be omitted from analysis.
+The MISSING subcommand determines whether user missing values are to
+be included or excluded in the analysis.
+
+The SUMMARY subcommand determines the type of summary analysis to be performed.
+Currently there is only one type: SUMMARY=TOTAL, which displays per-item
+analysis tested against the totals.
+
+
+
+@node ROC
+@section ROC
+
+@vindex ROC
+@cindex Receiver Operating Characterstic
+@cindex Area under curve
+
+@display
+ROC @var{var_list} BY @var{state_var} (@var{state_value})
+ /PLOT = @{ CURVE [(REFERENCE)], NONE @}
+ /PRINT = [ SE ] [ COORDINATES ]
+ /CRITERIA = [ CUTOFF(@{INCLUDE,EXCLUDE@}) ]
+ [ TESTPOS (@{LARGE,SMALL@}) ]
+ [ CI (@var{confidence}) ]
+ [ DISTRIBUTION (@{FREE, NEGEXPO @}) ]
+ /MISSING=@{EXCLUDE,INCLUDE@}
+@end display
+
+
+The @cmd{ROC} command is used to plot the receiver operating characteristic curve
+of a dataset, and to estimate the area under the curve.
+This is useful for analysing the efficacy of a variable as a predictor of a state of nature.
+
+The mandatory @var{var_list} is the list of predictor variables.
+The variable @var{state_var} is the variable whose values represent the actual states,
+and @var{state_value} is the value of this variable which represents the positive state.
+
+The optional subcommand PLOT is used to determine if and how the ROC curve is drawn.
+The keyword CURVE means that the ROC curve should be drawn, and the optional keyword REFERENCE,
+which should be enclosed in parentheses, says that the diagonal reference line should be drawn.
+If the keyword NONE is given, then no ROC curve is drawn.
+By default, the curve is drawn with no reference line.
+
+The optional subcommand PRINT determines which additional tables should be printed.
+Two additional tables are available.
+The SE keyword says that standard error of the area under the curve should be printed as well as
+the area itself.
+In addition, a p-value under the null hypothesis that the area under the curve equals 0.5 will be
+printed.
+The COORDINATES keyword says that a table of coordinates of the ROC curve should be printed.
+
+The CRITERIA subcommand has four optional parameters:
+@itemize @bullet
+@item The TESTPOS parameter may be LARGE or SMALL.
+LARGE is the default, and says that larger values in the predictor variables are to be
+considered positive. SMALL indicates that smaller values should be considered positive.
+
+@item The CI parameter specifies the confidence interval that should be printed.
+It has no effect if the SE keyword in the PRINT subcommand has not been given.
+
+@item The DISTRIBUTION parameter determines the method to be used when estimating the area
+under the curve.
+There are two possibilities, @i{viz}: FREE and NEGEXPO.
+The FREE method uses a non-parametric estimate, and the NEGEXPO method a bi-negative
+exponential distribution estimate.
+The NEGEXPO method should only be used when the number of positive actual states is
+equal to the number of negative actual states.
+The default is FREE.
+
+@item The CUTOFF parameter is for compatibility and is ignored.
+@end itemize
+
+The MISSING subcommand determines whether user missing values are to
+be included or excluded in the analysis. The default behaviour is to
+exclude them.
+Cases are excluded on a listwise basis; if any of the variables in @var{var_list}
+or if the variable @var{state_var} is missing, then the entire case will be
+excluded.
+
+