* DESCRIPTIVES:: Descriptive statistics.
* FREQUENCIES:: Frequency tables.
* EXAMINE:: Testing data for normality.
+* GRAPH:: Plot data.
* CORRELATIONS:: Correlation tables.
* CROSSTABS:: Crosstabulation tables.
* FACTOR:: Factor analysis and Principal Components analysis.
ZZZZ09, ZQZQ00 through ZQZQ09, in that sequence. In addition, Z score
variable names can be specified explicitly on @subcmd{VARIABLES} in the variable
list by enclosing them in parentheses after each variable.
+When Z scores are calculated, @pspp{} ignores @cmd{TEMPORARY},
+treating temporary transformations as permanent.
The @subcmd{STATISTICS} subcommand specifies the statistics to be displayed:
The @subcmd{HISTOGRAM} subcommand causes the output to include a histogram for
each specified numeric variable. The X axis by default ranges from
the minimum to the maximum value observed in the data, but the @subcmd{MINIMUM}
-and @subcmd{MAXIMUM} keywords can set an explicit range. Specify @subcmd{NORMAL} to
-superimpose a normal curve on the histogram. Histograms are not
-created for string variables.
+and @subcmd{MAXIMUM} keywords can set an explicit range. The number of
+bins are 2IQR(x)n^-1/3 according to the Freedman-Diaconis rule. (Note that
+@cmd{EXAMINE} uses a different algorithm to determine bin sizes.)
+Histograms are not created for string variables.
+
+Specify @subcmd{NORMAL} to superimpose a normal curve on the
+histogram.
@cindex piechart
The @subcmd{PIECHART} subcommand adds a pie chart for each variable to the data. Each
@vindex EXAMINE
@cindex Exploratory data analysis
-@cindex Normality, testing for
+@cindex normality, testing
@display
EXAMINE
dependent variable.
Following the dependent variables, factors may be specified.
-The factors (if desired) should be preceeded by a single @subcmd{BY} keyword.
+The factors (if desired) should be preceded by a single @subcmd{BY} keyword.
The format for each factor is
@display
@var{factorvar} [BY @var{subfactorvar}].
how the variance of differs between factors.
Boxplots will also show you the outliers and extreme values.
+@subcmd{HISTOGRAM} uses Sturges' rule to determine the number of
+bins, as approximately 1 + log2(n). (Note that @cmd{FREQUENCIES} uses a
+different algorithm to find the bin size.)
+
The @subcmd{SPREADLEVEL} plot displays the interquartile range versus the
median. It takes an optional parameter @var{t}, which specifies how the data
should be transformed prior to plotting.
The @subcmd{ID} subcommand is relevant only if @subcmd{/PLOT=BOXPLOT} or
@subcmd{/STATISTICS=EXTREME} has been given.
-If given, it shoule provide the name of a variable which is to be used
+If given, it should provide the name of a variable which is to be used
to labels extreme values and outliers.
Numeric or string variables are permissible.
-If the @subcmd{ID} subcommand is not given, then the casenumber will be used for
+If the @subcmd{ID} subcommand is not given, then the case number will be used for
labelling.
The @subcmd{CINTERVAL} subcommand specifies the confidence interval to use in
there are many distinct values, then @cmd{EXAMINE} will produce a very
large quantity of output.
+@node GRAPH
+@section GRAPH
+
+@vindex GRAPH
+@cindex Exploratory data analysis
+@cindex normality, testing
+
+@display
+GRAPH
+ /HISTOGRAM = @var{var}
+ /SCATTERPLOT [(BIVARIATE)] = @var{var1} WITH @var{var2} [BY @var{var3}]
+ [ /MISSING=@{LISTWISE, VARIABLE@} [@{EXCLUDE, INCLUDE@}] ]
+ [@{NOREPORT,REPORT@}]
+
+@end display
+
+The @cmd{GRAPH} produces graphical plots of data. Only one of the subcommands
+@subcmd{HISTOGRAM} or @subcmd{SCATTERPLOT} can be specified, i.e. only one plot
+can be produced per call of @cmd{GRAPH}. The @subcmd{MISSING} is optional.
+
+@cindex scatterplot
+
+The subcommand @subcmd{SCATTERPLOT} produces an xy plot of the data. The different
+values of the optional third variable @var{var3} will result in different colours and/or
+markers for the plot. The following is an example for producing a scatterplot.
+
+@example
+GRAPH
+ /SCATTERPLOT = @var{height} WITH @var{weight} BY @var{gender}.
+@end example
+
+This example will produce a scatterplot where @var{height} is plotted versus @var{weight}. Depending
+on the value of the @var{gender} variable, the colour of the datapoint is different. With
+this plot it is possible to analyze gender differences for @var{height} vs.@: @var{weight} relation.
+
+@cindex histogram
+
+The subcommand @subcmd{HISTOGRAM} produces a histogram. Only one variable is allowed for
+the histogram plot.
+For an alternative method to produce histograms @pxref{EXAMINE}. The
+following example produces a histogram plot for the variable @var{weight}.
+
+@example
+GRAPH
+ /HISTOGRAM = @var{weight}.
+@end example
+
@node CORRELATIONS
@section CORRELATIONS
crosstabulation tables to be displayed. It has a number of possible
settings:
-@itemize @asis
+@itemize @w{}
@item
@subcmd{TABLES}, the default, causes crosstabulation tables to be output.
@subcmd{NOTABLES} suppresses them.
@subcmd{STATISTICS} subcommand is not given, no statistics are calculated.
@strong{Please note:} Currently the implementation of @cmd{CROSSTABS} has the
-followings bugs:
+following bugs:
@itemize @bullet
@item
-Pearson's R (but not Spearman) is off a little.
-@item
-T values for Spearman's R and Pearson's R are wrong.
-@item
-Significance of symmetric and directional measures is not calculated.
+Significance of some symmetric and directional measures is not calculated.
@item
-Asymmetric ASEs and T values for lambda are wrong.
+Asymptotic standard error is not calculated for
+Goodman and Kruskal's tau or symmetric Somers' d.
@item
-ASE of Goodman and Kruskal's tau is not calculated.
-@item
-ASE of symmetric somers' d is wrong.
-@item
-Approximate T of uncertainty coefficient is wrong.
+Approximate T is not calculated for symmetric uncertainty coefficient.
@end itemize
Fixes for any of these deficiencies would be welcomed.
[ /EXTRACTION=@{PC, PAF@}]
- [ /ROTATION=@{VARIMAX, EQUAMAX, QUARTIMAX, NOROTATE@}]
+ [ /ROTATION=@{VARIMAX, EQUAMAX, QUARTIMAX, PROMAX[(@var{k})], NOROTATE@}]
[ /PRINT=[INITIAL] [EXTRACTION] [ROTATION] [UNIVARIATE] [CORRELATION] [COVARIANCE] [DET] [KMO] [SIG] [ALL] [DEFAULT] ]
used. By default Principal Components Analysis will be used.
The @subcmd{/ROTATION} subcommand is used to specify the method by which the extracted solution will be rotated.
-Three methods are available: @subcmd{VARIMAX} (which is the default), @subcmd{EQUAMAX}, and @subcmd{QUARTIMAX}.
-If don't want any rotation to be performed, the word @subcmd{NOROTATE} will prevent the command from performing any
-rotation on the data. Oblique rotations are not supported.
+Three orthogonal rotation methods are available:
+@subcmd{VARIMAX} (which is the default), @subcmd{EQUAMAX}, and @subcmd{QUARTIMAX}.
+There is one oblique rotation method, @i{viz}: @subcmd{PROMAX}.
+Optionally you may enter the power of the promax rotation @var{k}, which must be enclosed in parentheses.
+The default value of @var{k} is 5.
+If you don't want any rotation to be performed, the word @subcmd{NOROTATE} will prevent the command from performing any
+rotation on the data.
The @subcmd{/METHOD} subcommand should be used to determine whether the covariance matrix or the correlation matrix of the data is
to be analysed. By default, the correlation matrix is analysed.
The @subcmd{/CRITERIA} subcommand is used to specify how the number of extracted factors (components) are chosen.
If @subcmd{FACTORS(@var{n})} is
specified, where @var{n} is an integer, then @var{n} factors will be extracted. Otherwise, the @subcmd{MINEIGEN} setting will
-be used. @subcmd{MINEIGEN(@var{l})} requests that all factors whose eigenvalues are greater than or equal to @var{l} are extracted.
-The default value of @var{l} is 1. The @subcmd{ECONVERGE} and @subcmd{ITERATE} settings have effect only when iterative algorithms for factor
-extraction (such as Principal Axis Factoring) are used. @subcmd{ECONVERGE(@var{delta})} specifies that
+be used.
+@subcmd{MINEIGEN(@var{l})} requests that all factors whose eigenvalues are greater than or equal to @var{l} are extracted.
+The default value of @var{l} is 1.
+The @subcmd{ECONVERGE} setting has effect only when iterative algorithms for factor
+extraction (such as Principal Axis Factoring) are used.
+@subcmd{ECONVERGE(@var{delta})} specifies that
iteration should cease when
the maximum absolute value of the communality estimate between one iteration and the previous is less than @var{delta}. The
default value of @var{delta} is 0.001.
-The @subcmd{ITERATE(@var{m})} setting sets the maximum number of iterations to @var{m}. The default value of @var{m} is 25.
+The @subcmd{ITERATE(@var{m})} may appear any number of times and is used for two different purposes.
+It is used to set the maximum number of iterations (@var{m}) for convergence and also to set the maximum number of iterations
+for rotation.
+Whether it affects convergence or rotation depends upon which subcommand follows the @subcmd{ITERATE} subcommand.
+If @subcmd{EXTRACTION} follows, it affects convergence.
+If @subcmd{ROTATION} follows, it affects rotation.
+If neither @subcmd{ROTATION} nor @subcmd{EXTRACTION} follow a @subcmd{ITERATE} subcommand it will be ignored.
+The default value of @var{m} is 25.
The @cmd{MISSING} subcommand determines the handling of missing variables.
If @subcmd{INCLUDE} is set, then user-missing values are included in the
[/PRINT = [SUMMARY] [DEFAULT] [CI(@var{confidence})] [ALL]]
[/CRITERIA = [BCON(@var{min_delta})] [ITERATE(@var{max_interations})]
- [LCON(@var{min_likelihood_delta})] [EPS(@var{min_epsilon})]]
+ [LCON(@var{min_likelihood_delta})] [EPS(@var{min_epsilon})]
+ [CUT(@var{cut_point})]]
[/MISSING = @{INCLUDE|EXCLUDE@}]
@end display
@subcmd{/NOCONST} is a synonym for @subcmd{/ORIGIN}.
An iterative Newton-Raphson procedure is used to fit the model.
-The @subcmd{/CRITERIA} subcommand is used to specify the stopping criteria of the procedure.
+The @subcmd{/CRITERIA} subcommand is used to specify the stopping criteria of the procedure,
+and other parameters.
+The value of @var{cut_point} is used in the classification table. It is the
+threshold above which predicted values are considered to be 1. Values
+of @var{cut_point} must lie in the range [0,1].
During iterations, if any one of the stopping criteria are satisfied, the procedure is
considered complete.
-The criteria are:
+The stopping criteria are:
@itemize
@item The number of iterations exceeds @var{max_iterations}.
The default value of @var{max_iterations} is 20.
The default value of @var{min_epsilon} is 0.00000001.
@end itemize
+
The @subcmd{PRINT} subcommand controls the display of optional statistics.
Currently there is one such option, @subcmd{CI}, which indicates that the
confidence interval of the odds ratio should be displayed as well as its value.
The @subcmd{/EXPECTED} subcommand specifies the expected values of each
category.
There must be exactly one non-zero expected value, for each observed
-category, or the @subcmd{EQUAL} keywork must be specified.
+category, or the @subcmd{EQUAL} keyword must be specified.
You may use the notation @subcmd{@var{n}*@var{f}} to specify @var{n}
consecutive expected categories all taking a frequency of @var{f}.
The frequencies given are proportions, not absolute frequencies. The
The @subcmd{/WILCOXON} subcommand tests for differences between medians of the
variables listed.
The test does not make any assumptions about the variances of the samples.
-It does however assume that the distribution is symetrical.
+It does however assume that the distribution is symmetrical.
If the @subcmd{WITH} keyword is omitted, then tests for all
combinations of the listed variables are performed.
the name of the independent (or factor) variable.
You can use the @subcmd{STATISTICS} subcommand to tell @pspp{} to display
-ancilliary information. The options accepted are:
+ancillary information. The options accepted are:
@itemize
@item DESCRIPTIVES
Displays descriptive statistics about the groups factored by the independent
@end display
@cindex Cronbach's Alpha
-The @cmd{RELIABILTY} command performs reliability analysis on the data.
+The @cmd{RELIABILITY} command performs reliability analysis on the data.
The @subcmd{VARIABLES} subcommand is required. It determines the set of variables
upon which analysis is to be performed.