psych v1.7.5


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by William Revelle

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
iclust iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
ICLUST.cluster Function to form hierarchical cluster analysis of items
00.psych A package for personality, psychometric, and psychological research
Harman.political Eight political variables used by Harman (1967) as example 8.17
ICC Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
Gorsuch Example data set from Gorsuch (1997) for an example factor extension.
Harman.5 5 socio-economic variables from Harman (1967)
Harman.8 Correlations of eight physical variables (from Harman, 1966)
Harman Two 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
ICLUST.rgraph Draw an ICLUST graph using the Rgraphviz package
VSS.parallel Compare real and random VSS solutions
VSS.plot Plot VSS fits
Promax Perform bifactor, promax or targeted rotations and return the inter factor angles.
SD Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases
alpha Find two estimates of reliability: Cronbach's alpha and Guttman's Lambda 6.
VSS Apply the Very Simple Structure, MAP, and other criteria to determine the appropriate number of factors.
ability 16 ability items scored as correct or incorrect.
affect Two data sets of affect and arousal scores as a function of personality and movie conditions
Schmid 12 variables created by Schmid and Leiman to show the Schmid-Leiman Transformation
VSS.scree Plot the successive eigen values for a scree test
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.
ICLUST.sort Sort items by absolute size of cluster loadings
KMO Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy
block.random Create a block randomized structure for n independent variables
blot Bond's Logical Operations Test -- BLOT
cor.plot Create an image plot for a correlation or factor matrix
cor.smooth Smooth a non-positive definite correlation matrix to make it positive definite
cortest.mat Chi square tests of whether a single matrix is an identity matrix, or a pair of matrices are equal.
cosinor Functions for analysis of circadian or diurnal data
bfi 25 Personality items representing 5 factors
bi.bars Draw pairs of bargraphs based on two groups
Bechtoldt Seven data sets showing a bifactor solution.
bestScales A set of functions for factorial and empirical scale construction
cattell 12 cognitive variables from Cattell (1963)
circ.tests Apply four tests of circumplex versus simple structure
comorbidity Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
biplot.psych Draw biplots of factor or component scores by factor or component loadings
df2latex Convert a data frame, correlation matrix, or factor analysis output to a LaTeX table
dfOrder Sort (order) a dataframe or matrix by multiple columns
cor.wt The sample size weighted correlation may be used in correlating aggregated data
cor2dist Convert correlations to distances (necessary to do multidimensional scaling of correlation data)
correct.cor Find dis-attenuated correlations given correlations and reliabilities
cortest.bartlett Bartlett's test that a correlation matrix is an identity matrix
dummy.code Create dummy coded variables
Dwyer 8 cognitive variables used by Dwyer for an example.
cities Distances between 11 US cities
scoreOverlap Find correlations of composite variables (corrected for overlap) from a larger matrix.
cluster.plot Plot factor/cluster loadings and assign items to clusters by their highest loading.
eigen.loadings Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
ellipses Plot data and 1 and 2 sigma correlation ellipses
factor.rotate ``Hand" rotate a factor loading matrix
factor.scores Various ways to estimate factor scores for the factor analysis model
diagram Helper functions for drawing path model diagrams
draw.tetra Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation
factor.model Find R = F F' + U2 is the basic factor model
factor.residuals R* = R- F F'
bock Bock and Liberman (1970) data set of 1000 observations of the LSAT
burt 11 emotional variables from Burt (1915) cluster Fit: fit of the cluster model to a correlation matrix
cluster.loadings Find item by cluster correlations, corrected for overlap and reliability
corFiml Find a Full Information Maximum Likelihood (FIML) correlation or covariance matrix from a data matrix with missing data
corr.test Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame.
fa.poly Deprecated Exploratory Factor analysis functions. Please use fa
cluster2keys Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters.
cubits Galton's example of the relationship between height and 'cubit' or forearm length
describe Basic descriptive statistics useful for psychometrics
describeBy Basic summary statistics by group
epi Eysenck Personality Inventory (EPI) data for 3570 participants
epi.bfi 13 personality scales from the Eysenck Personality Inventory and Big 5 inventory
fa Exploratory Factor analysis using MinRes (minimum residual) as well as EFA by Principal Axis, Weighted Least Squares or Maximum Likelihood
densityBy Create a 'violin plot' or density plot of the distribution of a set of variables
errorCircles Two way plots of means, error bars, and sample sizes
error.crosses Plot x and y error bars
fa.extension Apply Dwyer's factor extension to find factor loadings for extended variables
fa.parallel Scree plots of data or correlation matrix compared to random ``parallel" matrices
interp.median Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
iqitems 16 multiple choice IQ items
kaiser Apply the Kaiser normalization when rotating factors
cohen.kappa Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
error.bars Plot means and confidence intervals Plot means and confidence intervals for multiple groups
fa.sort Sort factor analysis or principal components analysis loadings
fisherz Transformations of r including Fisher r to z and z to r and confidence intervals
galton Galton's Mid parent child height data
iclust.diagram Draw an ICLUST hierarchical cluster structure diagram
income US family income from US census 2008 Bootstrapped confidence intervals for raw and composite correlations
count.pairwise Count number of pairwise cases for a data set with missing (NA) data.
cta Simulate the C(ues) T(endency) A(ction) model of motivation
error.dots Show a dot.chart with error bars for different groups or variables
fa.multi Multi level (hierarchical) factor analysis
geometric.mean Find the geometric mean of a vector or columns of a data.frame.
glb.algebraic Find the greatest lower bound to reliability.
psych.misc Miscellaneous helper functions for the psych package
make.keys Create a keys matrix for use by score.items or cluster.cor
mat.sort Sort the elements of a correlation matrix to reflect factor loadings
multi.hist Multiple histograms with density and normal fits on one page
multilevel.reliability Find and plot various reliability/gneralizability coefficients for multilevel 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.item Generate simulated data structures for circumplex, spherical, or simple structure
mixedCor Find correlations for mixtures of continuous, polytomous, and dichotomous variables
phi2tetra Convert a phi coefficient to a tetrachoric correlation
plot.psych Plotting functions for the psych package of class ``psych"
msq 75 mood items from the Motivational State Questionnaire for 3896 participants
mssd Find von Neuman's Mean Square of Successive Differences
pairs.panels SPLOM, histograms and correlations for a data matrix
splitHalf Alternative estimates of test reliabiity
harmonic.mean Find the harmonic mean of a vector, matrix, or columns of a data.frame
irt.fa Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations
irt.item.diff.rasch Simple function to estimate item difficulties using IRT concepts
esem Perform and Exploratory Structural Equation Model (ESEM) by using factor extension techniques
factor.congruence Coefficient of factor congruence How well does the factor model fit a correlation matrix. Part of the VSS package
factor.stats Find various goodness of fit statistics for factor analysis and principal components
print.psych Print and summary functions for the psych class
r.test Tests of significance for correlations
sim.VSS create VSS like data
sim.anova Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures.
structure.diagram Draw a structural equation model specified by two measurement models and a structural model
structure.list Create factor model matrices from an input list
matrix.addition A function to add two vectors or matrices
mediate Estimate and display direct and indirect effects of mediators and moderator in path models
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
sim.multilevel Simulate multilevel data with specified within group and between group correlations
withinBetween An example of the distinction between within group and between group correlations
factor2cluster Extract cluster definitions from factor loadings
headTail Combine calls to head and tail
heights A data.frame of the Galton (1888) height and cubit data set.
omega.graph Graph hierarchical factor structures
parcels Find miniscales (parcels) of size 2 or 3 from a set of items
rangeCorrection Correct correlations for restriction of range. (Thorndike Case 2)
read.file Shortcuts for reading from the clipboard or a file
polar Convert Cartesian factor loadings into polar coordinates
polychor.matrix Phi or Yule coefficient matrix to polychoric coefficient matrix
predict.psych Prediction function for factor analysis or principal components
principal Principal components analysis (PCA)
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.
mardia Calculate univariate or multivariate (Mardia's test) skew and kurtosis for a vector, matrix, or data.frame
smc Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix
test.irt A simple demonstration (and test) of various IRT scoring algorthims.
test.psych Testing of functions in the psych package
outlier Find and graph Mahalanobis squared distances to detect outliers
phi Find the phi coefficient of correlation between two dichotomous variables
phi.demo A simple demonstration of the Pearson, phi, and polychoric corelation
reverse.code Reverse the coding of selected items prior to scale analysis
setCor Set Correlation and Multiple Regression from matrix or raw input
sim Functions to simulate psychological/psychometric data.
tetrachoric Tetrachoric, polychoric, biserial and polyserial correlations from various types of input
thurstone Thurstone Case V scaling
fa.diagram Graph factor loading matrices
irt.1p Item Response Theory estimate of theta (ability) using a Rasch (like) model
irt.responses Plot probability of multiple choice responses as a function of a latent trait
logistic Logistic transform from x to p and logit transform from p to x
vegetables Paired comparison of preferences for 9 vegetables
winsor Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame
sat.act 3 Measures of ability: SATV, SATQ, ACT
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
simulation.circ Simulations of circumplex and simple structure
superMatrix Form a super matrix from two sub matrices.
table2matrix Convert a table with counts to a matrix or data.frame representing those counts.
lowerUpper Combine two square matrices to have a lower off diagonal for one, upper off diagonal for the other
neo NEO correlation matrix from the NEO_PI_R manual
omega Calculate McDonald's omega estimates of general and total factor saturation
partial.r Find the partial correlations for a set (x) of variables with set (y) removed.
sim.structure Create correlation matrices or data matrices with a particular measurement and structural model
peas Galton`s Peas
rescale Function to convert scores to ``conventional
residuals.psych Extract residuals from various psych objects
schmid Apply the Schmid Leiman transformation to a correlation matrix
score.alpha Score scales and find Cronbach's alpha as well as associated statistics
sim.congeneric Simulate a congeneric data set
sim.hierarchical Create a population or sample correlation matrix, perhaps with hierarchical structure.
spider Make "radar" or "spider" plots.
statsBy Find statistics (including correlations) within and between groups for basic multilevel analyses
tr Find the trace of a square matrix
unidim Several indices of the unidimensionality of a set of variables.
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Date 2017-05-01
License GPL (>= 2)
LazyData true
NeedsCompilation no
Packaged 2017-05-02 23:28:02 UTC; WR
Repository CRAN
Date/Publication 2017-05-03 07:34:19 UTC

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