* 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
+* FACTOR:: Factor analysis and Principal Components analysis.
+* LOGISTIC REGRESSION:: Bivariate Logistic Regression.
* MEANS:: Average values and other statistics.
* NPAR TESTS:: Nonparametric tests.
* T-TEST:: Test hypotheses about means.
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:
@table @code
-@item ALL
+@item @subcmd{ALL}
All of the statistics below.
-@item MEAN
+@item @subcmd{MEAN}
Arithmetic mean.
-@item SEMEAN
+@item @subcmd{SEMEAN}
Standard error of the mean.
-@item STDDEV
+@item @subcmd{STDDEV}
Standard deviation.
-@item VARIANCE
+@item @subcmd{VARIANCE}
Variance.
-@item KURTOSIS
+@item @subcmd{KURTOSIS}
Kurtosis and standard error of the kurtosis.
-@item SKEWNESS
+@item @subcmd{SKEWNESS}
Skewness and standard error of the skewness.
-@item RANGE
+@item @subcmd{RANGE}
Range.
@item MINIMUM
Minimum value.
@vindex EXAMINE
@cindex Exploratory data analysis
-@cindex Normality, testing for
+@cindex normality, testing
@display
EXAMINE
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 height is plotted versus weight. Depending
+on the value of the gender variable, the colour of the datapoint is different. With
+this plot it is possible to analyze gender differences for height vs. 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 variable weigth.
+
+@example
+GRAPH
+ /HISTOGRAM = @var{weight}.
+@end example
+
@node CORRELATIONS
@section CORRELATIONS
calculations, but system-missing values are not.
If @subcmd{EXCLUDE} is set, which is the default, user-missing
values are excluded as well as system-missing values.
-This is the default.
If @subcmd{LISTWISE} is set, then the entire case is excluded from analysis
whenever any variable specified in any @cmd{/VARIABLES} subcommand
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.
-@item
-Asymmetric ASEs and T values for lambda are wrong.
+Significance of some symmetric and directional measures is not calculated.
@item
-ASE of Goodman and Kruskal's tau is not calculated.
+Asymptotic standard error is not calculated for
+Goodman and Kruskal's tau or symmetric Somers' d.
@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.
The @subcmd{/PRINT} subcommand may be used to select which features of the analysis are reported:
-@itemize @subcmd{}
-@item UNIVARIATE
+@itemize
+@item @subcmd{UNIVARIATE}
A table of mean values, standard deviations and total weights are printed.
-@item INITIAL
+@item @subcmd{INITIAL}
Initial communalities and eigenvalues are printed.
-@item EXTRACTION
+@item @subcmd{EXTRACTION}
Extracted communalities and eigenvalues are printed.
-@item ROTATION
+@item @subcmd{ROTATION}
Rotated communalities and eigenvalues are printed.
-@item CORRELATION
+@item @subcmd{CORRELATION}
The correlation matrix is printed.
-@item COVARIANCE
+@item @subcmd{COVARIANCE}
The covariance matrix is printed.
-@item DET
+@item @subcmd{DET}
The determinant of the correlation or covariance matrix is printed.
-@item KMO
+@item @subcmd{KMO}
The Kaiser-Meyer-Olkin measure of sampling adequacy and the Bartlett test of sphericity is printed.
-@item SIG
+@item @subcmd{SIG}
The significance of the elements of correlation matrix is printed.
-@item ALL
+@item @subcmd{ALL}
All of the above are printed.
-@item DEFAULT
+@item @subcmd{DEFAULT}
Identical to @subcmd{INITIAL} and @subcmd{EXTRACTION}.
@end itemize
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
values for the particular coefficient are missing.
The default is @subcmd{LISTWISE}.
+@node LOGISTIC REGRESSION
+@section LOGISTIC REGRESSION
+
+@vindex LOGISTIC REGRESSION
+@cindex logistic regression
+@cindex bivariate logistic regression
+
+@display
+LOGISTIC REGRESSION [VARIABLES =] @var{dependent_var} WITH @var{predictors}
+
+ [/CATEGORICAL = @var{categorical_predictors}]
+
+ [@{/NOCONST | /ORIGIN | /NOORIGIN @}]
+
+ [/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})]
+ [CUT(@var{cut_point})]]
+
+ [/MISSING = @{INCLUDE|EXCLUDE@}]
+@end display
+
+Bivariate Logistic Regression is used when you want to explain a dichotomous dependent
+variable in terms of one or more predictor variables.
+
+The minimum command is
+@example
+LOGISTIC REGRESSION @var{y} WITH @var{x1} @var{x2} @dots{} @var{xn}.
+@end example
+Here, @var{y} is the dependent variable, which must be dichotomous and @var{x1} @dots{} @var{xn}
+are the predictor variables whose coefficients the procedure estimates.
+
+By default, a constant term is included in the model.
+Hence, the full model is
+@math{
+{\bf y}
+= b_0 + b_1 {\bf x_1}
++ b_2 {\bf x_2}
++ \dots
++ b_n {\bf x_n}
+}
+
+Predictor variables which are categorical in nature should be listed on the @subcmd{/CATEGORICAL} subcommand.
+Simple variables as well as interactions between variables may be listed here.
+
+If you want a model without the constant term @math{b_0}, use the keyword @subcmd{/ORIGIN}.
+@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,
+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 stopping criteria are:
+@itemize
+@item The number of iterations exceeds @var{max_iterations}.
+ The default value of @var{max_iterations} is 20.
+@item The change in the all coefficient estimates are less than @var{min_delta}.
+The default value of @var{min_delta} is 0.001.
+@item The magnitude of change in the likelihood estimate is less than @var{min_likelihood_delta}.
+The default value of @var{min_delta} is zero.
+This means that this criterion is disabled.
+@item The differential of the estimated probability for all cases is less than @var{min_epsilon}.
+In other words, the probabilities are close to zero or one.
+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.
+@subcmd{CI} should be followed by an integer in parentheses, to indicate the
+confidence level of the desired confidence interval.
+
+The @subcmd{MISSING} subcommand determines the handling of missing
+variables.
+If @subcmd{INCLUDE} is set, then user-missing values are included in the
+calculations, but system-missing values are not.
+If @subcmd{EXCLUDE} is set, which is the default, user-missing
+values are excluded as well as system-missing values.
+This is the default.
+
@node MEANS
@section MEANS
projects / pspp / blobdiff