Dr. Dirk Enzmann - Statistical Software - Dirk Enzmann's gimmicks
For archival purposes, local mirrors of many but not all of the SPSS, Excel-Based, and Executable code can be found in: http://psyphz.psych.wisc.edu/~shackman/
To download the files, manually add the name of a particular piece of code to http://psyphz.psych.wisc.edu/~shackman/
e.g., http://psyphz.psych.wisc.edu/~shackman/rbis.sps
It is preferable, however, to use the downloads available at Dr. Dirk Enzmann's site.
------------------------------
Below you find some small programs, SPSS macros, EXCEL-templates, and R functions (see: http://www.r-project.org/) I wrote for special calculations in statistical analyses. The programs are written in Pascal 7.0 and run under Windows (3.x, 9x, NT4, XP). The files can be downloaded and spread without further permisson under the condition that they remain unchanged. They have been tested as virus free. The author is not liable to any damages caused by their use. Comments on improvements are welcome.
BetaDiff:
For calculating confidence intervals and testing the significance of
the difference of two beta-coefficients from independent samples
BetaDiff.exe ( description
) ( download
)
Center:
SPSS macro for centering a set of variables (with listwise deletion of
missing cases); useful for computing products of variables for
interaction terms in regression analyses.
Center.sps ( download
)
CorrTot:
Executable program and R function for computing pooled means, standard
deviations and a pooled
correlation matrix from means, standard deviations and correlation
matrices of two independent samples
CorrTot.zip ( description
) ( download
) corrtot.r (R-function)
CovMat:
SPSS macro for writing a covariance matrix of a set of variables (with
listwise deletion of missing cases) to a text file
CovMat.sps ( download
)
Crosstabs:
R function to simulate the SPSS procedure
CROSSTABS.
crosstabs.r ( download
)
DumCode:
SPSS macro for creating dummy variables (indicator coding) of a nominal
variable. Useful for regression analyses with independent variables
that are categorical.
DumCode.sps ( download
)
Fa.promax:
R function to compute maximum likelihood factor analysis with varimax
and promax rotation; allows specification of promax power and sorting
of loadings; output
includes correlation matrix of factors and (optionally) matrices of
factor scores
fa.promax ( download
)
Freq:
R function to simulate the SPSS procedure
FREQUENCIES.
freq.r ( download
)
Hist.KDNC:
R function to plot a histogram overlayed by a
kernel density and a normal curve.
hist.kdnc.r ( download
)
IntGraph:
Excel-template for drawing interaction plots of a regression equation
with interaction term.
IntGraph.xlt ( description
) ( download
)
Kurtosis:
R function to compute the unbiased population
estimate or biased sample statistic of kurtosis.
kurtosis.r ( download
)
LogRegR2:
R function to calculate Chi² model fit and R² analogs (pseudo
R²: McFadden's R², Cox & Snell index, Nagelkerke index)
of a logistic regression model obtained by glm(..., family =
'binomial').
LogRegR2.r ( download
)
MeanSD:
For computing interactively the mean and standard deviation of a
combined sample from up to 50 independent samples.
MeanSD.exe ( download
)
MeanSDF:
Same as MeanSD for up to 1000 samples and input file as input.
MeanSDF.exe ( description
) ( download
)
Median:
SPSS-macro for calculating the median and quartiles of a variable
(optionally for all values of a break variable) according to one of six
different methods.
Median.sps ( description
) ( download
)
Miss2Sys:
SPSS-script to recode all missing values of all numeric variables to
system missing values (useful if you want to import an SPSS data file
with different missing values in R).
Miss2Sys.sbs ( description
) ( download
)
Part_tst:
SPSS-macro for testing the difference between two standardized
regression coefficients of the same equation (one sample).
part_tst.sps ( description
) ( download
)
PCA
R-function to compute a principal components "factor" analysis (PCA)
with varimax
and promax rotation; different options for the number of
components (factors): direct specification, parallel test
criteria (random eigenvalues), or minimum eigenvalue;
optionally specification of promax power, sorting
of loadings, and matrices of factor scores (see also: RanEigen and
Fa.promax)
pca.r
( download
)
Plot.fitPoisNegb:
R function to plot the proportion of the observed counts and the fitted
(expected)
probabilities of the poisson and negative binomial distributed counts
of a variable.
plot.fitPoisNegb.r ( download
)
Plot.KDNC:
R function to plot a kernel density curve
overlayed by a normal curve.
plot.kdnc.r ( download
)
Plot.power:
R function to calculate and plot power of a one sample z-test of a
sample mean
plot.power.r ( download
)
ProfSim:
SPSS-macro for calculating different measures of profile similarity
based on two sets of variables.
ProfSim.sps (description: see comments at the end of the macro) ( download
)
RanEigen:
For determining the number of components (factors) to retain in a
principal component analysis (PCA) by using random eigenvalues
(parallel analysis).
PACrit.exe ( how
to install RanEigen? ) ( download
self-extracting file )
RelDiff:
For computing the reliability of a difference score (gain score)
according to Zimmerman & Williams (1982).
RelDiff.exe ( download
)
r_bis:
SPSS macro for computing a biserial correlation coefficient and its
significance.
r_bis.sps ( download
)
Example for using the macros r_bis and r_tetra: Examp_r.sps
( download
)
R_Prob:
For calculating the significance, 95%-confidence interval, and Fisher's
Z value of a Pearson correlation coefficient r (given sample size n).
R_Prob.exe ( download
)
r_tetra:
SPSS macro for computing a tetrachoric correlation coefficient and its
significance (see also: TetCorr).
r_tetra.sps ( download
)
Example for using the macros r_bis and r_tetra: Examp_r.sps ( download
)
Skewness:
R function to compute the unbiased population
estimate or biased sample statistic of skewness.
skewness.r ( download
)
SPSS2Stata:
SPSS script for converting an SPSS data file (.sav) into a Stata data
file (.dta)
spss2stata.sbs ( description
) ( download
)
t_Test:
For testing the difference in means between two indepedent samples
(given means, standard deviations and sample sizes of both samples).
t_Test.exe ( description
) ( download
)
TetCorr:
DOS program and source code (Pascal) for computing a matrix of
tetrachoric correlation coefficients of up to 50 variables and a
maximum of 8,000 cases (see also: r_tetra).
TetCorr.zip ( description
) ( download
)
TRd:
For computing the Satorra-Bentler scaled chi-square difference test
(TRd) based on the MLM estimators obtained by MPlus, see: http://www.statmodel.com/chidiff.html
TRd.exe ( download
)
VDef2SPS:
SPSS script for creating SPSS syntax to define the variables (variable
labels, value labels, and missing values) according to the definitions
of a specific SPSS data file (*.sav).
VDef2SPS.sbs ( description
) ( download
)
For an extremely useful source of SPSS macros see: http://www.spsstools.net
