psych v2.0.12


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Procedures for Psychological, Psychometric, and Personality Research

A general purpose toolbox for personality, psychometric theory and experimental psychology. Functions are primarily for multivariate analysis and scale construction using factor analysis, principal component analysis, cluster analysis and reliability analysis, although others provide basic descriptive statistics. Item Response Theory is done using factor analysis of tetrachoric and polychoric correlations. Functions for analyzing data at multiple levels include within and between group statistics, including correlations and factor analysis. Functions for simulating and testing particular item and test structures are included. Several functions serve as a useful front end for structural equation modeling. Graphical displays of path diagrams, factor analysis and structural equation models are created using basic graphics. Some of the functions are written to support a book on psychometric theory as well as publications in personality research. For more information, see the <> web page.

Functions in psych

Name Description
Gorsuch Example data set from Gorsuch (1997) for an example factor extension.
Garcia Data from the sexism (protest) study of Garcia, Schmitt, Branscome, and Ellemers (2010)
Gleser Example data from Gleser, Cronbach and Rajaratnam (1965) to show basic principles of generalizability theory.
AUC Decision Theory measures of specificity, sensitivity, and d prime
ICC Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
Harman Five data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt
ICLUST.graph create control code for ICLUST graphical output
00.psych A package for personality, psychometric, and psychological research
ICLUST.cluster Function to form hierarchical cluster analysis of items
ICLUST.sort Sort items by absolute size of cluster loadings
KMO Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy
iclust iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
ICLUST.rgraph Draw an ICLUST graph using the Rgraphviz package
Schmid 12 variables created by Schmid and Leiman to show the Schmid-Leiman Transformation
SD Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases
Promax Perform Procustes,bifactor, promax or targeted rotations and return the inter factor angles.
VSS Apply the Very Simple Structure, MAP, and other criteria to determine the appropriate number of factors.
VSS.parallel Compare real and random VSS solutions
Pinv Compute the Moore-Penrose Pseudo Inverse of a matrix
Tucker 9 Cognitive variables discussed by Tucker and Lewis (1973)
Bechtoldt Seven data sets showing a bifactor solution.
bfi 25 Personality items representing 5 factors
bassAckward The Bass-Ackward factoring algorithm discussed by Goldberg
anova.psych Model comparison for regression, mediation, and factor analysis
bi.bars Draw pairs of bargraphs based on two groups
VSS.plot Plot VSS fits
Yule From a two by two table, find the Yule coefficients of association, convert to phi, or tetrachoric, recreate table the table to create the Yule coefficient.
bestScales A bootstrap aggregation function for choosing most predictive unit weighted items
bock Bock and Liberman (1970) data set of 1000 observations of the LSAT
cattell 12 cognitive variables from Cattell (1963)
VSS.scree Plot the successive eigen values for a scree test
biplot.psych Draw biplots of factor or component scores by factor or component loadings
alpha Find two estimates of reliability: Cronbach's alpha and Guttman's Lambda 6.
block.random Create a block randomized structure for n independent variables
circ.tests Apply four tests of circumplex versus simple structure
cluster.plot Plot factor/cluster loadings and assign items to clusters by their highest loading.
scoreOverlap Find correlations of composite variables (corrected for overlap) from a larger matrix.
cluster2keys Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters. cluster Fit: fit of the cluster model to a correlation matrix
cor.smooth Smooth a non-positive definite correlation matrix to make it positive definite
corr.test Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame.
cluster.loadings Find item by cluster correlations, corrected for overlap and reliability
cor.wt The sample size weighted correlation may be used in correlating aggregated data
corCi Bootstrapped and normal confidence intervals for raw and composite correlations
cor.plot Create an image plot for a correlation or factor matrix
comorbidity Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
cohen.d Find Cohen d and confidence intervals
correct.cor Find dis-attenuated correlations given correlations and reliabilities
corFiml Find a Full Information Maximum Likelihood (FIML) correlation or covariance matrix from a data matrix with missing data
cor2dist Convert correlations to distances (necessary to do multidimensional scaling of correlation data)
cta Simulate the C(ues) T(endency) A(ction) model of motivation
densityBy Create a 'violin plot' or density plot of the distribution of a set of variables
cortest.mat Chi square tests of whether a single matrix is an identity matrix, or a pair of matrices are equal.
cortest.bartlett Bartlett's test that a correlation matrix is an identity matrix
diagram Helper functions for drawing path model diagrams
fa.poly Deprecated Exploratory Factor analysis functions. Please use fa
describeBy Basic summary statistics by group
describe Basic descriptive statistics useful for psychometrics
ellipses Plot data and 1 and 2 sigma correlation ellipses
error.dots Show a dot.chart with error bars for different groups or variables
error.crosses Plot x and y error bars
error.bars Plot means and confidence intervals
Dwyer 8 cognitive variables used by Dwyer for an example. Plot means and confidence intervals for multiple groups
eigen.loadings Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
errorCircles Two way plots of means, error bars, and sample sizes
cosinor Functions for analysis of circadian or diurnal data
pairwiseCount Count number of pairwise cases for a data set with missing (NA) data and impute values.
draw.tetra Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation
dummy.code Create dummy coded variables
fa.multi Multi level (hierarchical) factor analysis
fa.lookup A set of functions for factorial and empirical scale construction
fa.diagram Graph factor loading matrices
fa.parallel Scree plots of data or correlation matrix compared to random ``parallel" matrices
faCor Correlations between two factor analysis solutions
fa.random A first approximation to Random Effects Exploratory Factor Analysis
factor.congruence Coefficient of factor congruence
esem Perform and Exploratory Structural Equation Model (ESEM) by using factor extension techniques
factor.model Find R = F F' + U2 is the basic factor model How well does the factor model fit a correlation matrix. Part of the VSS package
fa Exploratory Factor analysis using MinRes (minimum residual) as well as EFA by Principal Axis, Weighted Least Squares or Maximum Likelihood
fa.sort Sort factor analysis or principal components analysis loadings
fa.extension Apply Dwyer's factor extension to find factor loadings for extended variables
factor.stats Find various goodness of fit statistics for factor analysis and principal components
factor.residuals R* = R- F F'
headTail Combine calls to head and tail
irt.item.diff.rasch Simple function to estimate item difficulties using IRT concepts
fparse Parse and exten formula input from a model and return the DV, IV, and associated terms.
glb.algebraic Find the greatest lower bound to reliability.
fisherz Transformations of r, d, and t including Fisher r to z and z to r and confidence intervals
factor2cluster Extract cluster definitions from factor loadings
geometric.mean Find the geometric mean of a vector or columns of a data.frame.
cohen.kappa Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
manhattan "Manhattan" plots of correlations with a set of criteria.
irt.1p Item Response Theory estimate of theta (ability) using a Rasch (like) model
mat.sort Sort the elements of a correlation matrix to reflect factor loadings
lowerUpper Combine two square matrices to have a lower off diagonal for one, upper off diagonal for the other
factor.rotate ``Hand" rotate a factor loading matrix
mediate Estimate and display direct and indirect effects of mediators and moderator in path models
iclust.diagram Draw an ICLUST hierarchical cluster structure diagram
logistic Logistic transform from x to p and logit transform from p to x
make.keys Create a keys matrix for use by score.items or cluster.cor
harmonic.mean Find the harmonic mean of a vector, matrix, or columns of a data.frame
matrix.addition A function to add two vectors or matrices
splitHalf Alternative estimates of test reliabiity
multilevel.reliability Find and plot various reliability/gneralizability coefficients for multilevel data
omega Calculate McDonald's omega estimates of general and total factor saturation
factor.scores Various ways to estimate factor scores for the factor analysis model
omega.graph Graph hierarchical factor structures
outlier Find and graph Mahalanobis squared distances to detect outliers
kaiser Apply the Kaiser normalization when rotating factors
irt.responses Plot probability of multiple choice responses as a function of a latent trait
plot.psych Plotting functions for the psych package of class ``psych"
interp.median Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
psych.misc Miscellaneous helper functions for the psych package
p.rep Find the probability of replication for an F, t, or r and estimate effect size
paired.r Test the difference between (un)paired correlations
pairs.panels SPLOM, histograms and correlations for a data matrix
irt.fa Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations
phi.demo A simple demonstration of the Pearson, phi, and polychoric corelation
phi2tetra Convert a phi coefficient to a tetrachoric correlation
mixedCor Find correlations for mixtures of continuous, polytomous, and dichotomous variables
predict.psych Prediction function for factor analysis, principal components (pca), bestScales
polychor.matrix Phi or Yule coefficient matrix to polychoric coefficient matrix
polar Convert Cartesian factor loadings into polar coordinates
sat.act 3 Measures of ability: SATV, SATQ, ACT
reverse.code Reverse the coding of selected items prior to scale analysis
scaling.fits Test the adequacy of simple choice, logistic, or Thurstonian scaling.
scatterHist Draw a scatter plot with associated X and Y histograms, densities and correlation
print.psych Print and summary functions for the psych class
partial.r Find the partial correlations for a set (x) of variables with set (y) removed.
principal Principal components analysis (PCA)
parcels Find miniscales (parcels) of size 2 or 3 from a set of items
rangeCorrection Correct correlations for restriction of range. (Thorndike Case 2)
r.test Tests of significance for correlations
phi Find the phi coefficient of correlation between two dichotomous variables
residuals.psych Extract residuals from various psych objects
multi.hist Multiple histograms with density and normal fits on one page
mssd Find von Neuman's Mean Square of Successive Differences
rescale Function to convert scores to ``conventional " metrics
score.multiple.choice Score multiple choice items and provide basic test statistics
scrub A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA.
setCor Multiple Regression and Set Correlation from matrix or raw input
schmid Apply the Schmid Leiman transformation to a correlation matrix
score.alpha Score scales and find Cronbach's alpha as well as associated statistics
scoreWtd Score items using regression or correlation based weights
sim Functions to simulate psychological/psychometric data.
scoreIrt Find Item Response Theory (IRT) based scores for dichotomous or polytomous items
scoreItems Score item composite scales and find Cronbach's alpha, Guttman lambda 6 and item whole correlations
sim.VSS create VSS like data
simulation.circ Simulations of circumplex and simple structure
sim.structure Create correlation matrices or data matrices with a particular measurement and structural model
sim.multilevel Simulate multilevel data with specified within group and between group correlations
sim.anova Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures.
smc Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix
Spengler Project Talent data set from Marion Spengler and Rodica Damian
mardia Calculate univariate or multivariate (Mardia's test) skew and kurtosis for a vector, matrix, or data.frame
sim.congeneric Simulate a congeneric data set
sim.hierarchical Create a population or sample correlation matrix, perhaps with hierarchical structure.
sim.item Generate simulated data structures for circumplex, spherical, or simple structure
test.psych Testing of functions in the psych package
Tal_Or Data set testing causal direction in presumed media influence
test.irt A simple demonstration (and test) of various IRT scoring algorthims.
testRetest Find various test-retest statistics, including test, person and item reliability
statsBy Find statistics (including correlations) within and between groups for basic multilevel analyses
structure.list Create factor model matrices from an input list
structure.diagram Draw a structural equation model specified by two measurement models and a structural model
spider Make "radar" or "spider" plots.
superMatrix Form a super matrix from two sub matrices.
table2matrix Convert a table with counts to a matrix or data.frame representing those counts.
unidim Several indices of the unidimensionality of a set of variables.
withinBetween An example of the distinction between within group and between group correlations
tr Find the trace of a square matrix
winsor Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame
tetrachoric Tetrachoric, polychoric, biserial and polyserial correlations from various types of input
thurstone Thurstone Case V scaling
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Date 2020-12-14
License GPL (>= 2)
LazyData yes
ByteCompile TRUE
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Packaged 2020-12-16 00:46:41 UTC; WR
Repository CRAN
Date/Publication 2020-12-16 16:10:03 UTC

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