# psych v1.6.12

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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 personality-project.org/r web page.

## Functions in psych

 Name Description blot Bond's Logical Operations Test -- BLOT bi.bars Draw pairs of bargraphs based on two groups Bechtoldt Seven data sets showing a bifactor solution. 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. bfi 25 Personality items representing 5 factors burt 11 emotional variables from Burt (1915) bock Bock and Liberman (1970) data set of 1000 observations of the LSAT affect Two data sets of affect and arousal scores as a function of personality and movie conditions ability 16 ability items scored as correct or incorrect. cities Distances between 11 US cities scoreOverlap Find correlations of composite variables (corrected for overlap) from a larger matrix. cattell 12 cognitive variables from Cattell (1963) cluster.fit cluster Fit: fit of the cluster model to a correlation matrix comorbidity Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics circ.tests Apply four tests of circumplex versus simple structure cluster.loadings Find item by cluster correlations, corrected for overlap and reliability cor.ci Bootstrapped confidence intervals for raw and composite correlations cluster2keys Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters. cluster.plot Plot factor/cluster loadings and assign items to clusters by their highest loading. cushny A data set from Cushny and Peebles (1905) on the effect of three drugs on hours of sleep, used by Student (1908) correct.cor Find dis-attenuated correlations given correlations and reliabilities densityBy Create a 'violin plot' or density plot of the distribution of a set of variables corr.test Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame. error.bars.by Plot means and confidence intervals for multiple groups 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 error.bars Plot means and confidence intervals describeBy Basic summary statistics by group fa.poly Deprecated Exploratory Factor analysis functions. Please use fa epi Eysenck Personality Inventory (EPI) data for 3570 participants epi.bfi 13 personality scales from the Eysenck Personality Inventory and Big 5 inventory cta Simulate the C(ues) T(endency) A(ction) model of motivation 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 cubits Galton's example of the relationship between height and 'cubit' or forearm length 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.congruence Coefficient of factor congruence fa.parallel Scree plots of data or correlation matrix compared to random parallel" matrices Gleser Example data from Gleser, Cronbach and Rajaratnam (1965) to show basic principles of generalizability theory. factor.fit How well does the factor model fit a correlation matrix. Part of the VSS package Gorsuch Example data set from Gorsuch (1997) for an example factor extension. iclust.diagram Draw an ICLUST hierarchical cluster structure diagram ICLUST.cluster Function to form hierarchical cluster analysis of items count.pairwise Count number of pairwise cases for a data set with missing (NA) data. cosinor Functions for analysis of circadian or diurnal data diagram Helper functions for drawing path model diagrams draw.tetra Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation errorCircles Two way plots of means, error bars, and sample sizes harmonic.mean Find the harmonic mean of a vector, matrix, or columns of a data.frame error.crosses Plot x and y error bars fa Exploratory Factor analysis using MinRes (minimum residual) as well as EFA by Principal Axis, Weighted Least Squares or Maximum Likelihood fa.extension Apply Dwyer's factor extension to find factor loadings for extended variables fisherz Transformations of r including Fisher r to z and z to r and confidence intervals headTail Combine calls to head and tail factor.rotate Hand" rotate a factor loading matrix factor2cluster Extract cluster definitions from factor loadings factor.scores Various ways to estimate factor scores for the factor analysis model ICLUST.graph create control code for ICLUST graphical output kaiser Apply the Kaiser normalization when rotating factors iclust iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles cohen.kappa Find Cohen's kappa and weighted kappa coefficients for correlation of two raters make.keys Create a keys matrix for use by score.items or cluster.cor income US family income from US census 2008 r.test Tests of significance for correlations phi Find the phi coefficient of correlation between two dichotomous variables mat.sort Sort the elements of a correlation matrix to reflect factor loadings interp.median Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame phi.demo A simple demonstration of the Pearson, phi, and polychoric corelation scrub A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA. rescale Function to convert scores to conventional " metrics read.file Shortcuts for reading from the clipboard or a file rangeCorrection Correct correlations for restriction of range. (Thorndike Case 2) msq 75 mood items from the Motivational State Questionnaire for 3896 participants SD Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases table2matrix Convert a table with counts to a matrix or data.frame representing those counts. superMatrix Form a super matrix from two sub matrices. mssd Find von Neuman's Mean Square of Successive Differences polar Convert Cartesian factor loadings into polar coordinates polychor.matrix Phi or Yule coefficient matrix to polychoric coefficient matrix sat.act 3 Measures of ability: SATV, SATQ, ACT smc Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix scaling.fits Test the adequacy of simple choice, logistic, or Thurstonian scaling. sim.hierarchical Create a population or sample correlation matrix, perhaps with hierarchical structure. sim.congeneric Simulate a congeneric data set spider Make "radar" or "spider" plots. test.psych Testing of functions in the psych package test.irt A simple demonstration (and test) of various IRT scoring algorthims. vegetables Paired comparison of preferences for 9 vegetables ICLUST.rgraph Draw an ICLUST graph using the Rgraphviz package ICLUST.sort Sort items by absolute size of cluster loadings VSS Apply the Very Simple Structure, MAP, and other criteria to determine the appropriate number of factors. p.rep Find the probability of replication for an F, t, or r and estimate effect size outlier Find and graph Mahalanobis squared distances to detect outliers plot.psych Plotting functions for the psych package of class psych" schmid Apply the Schmid Leiman transformation to a correlation matrix phi2tetra Convert a phi coefficient to a tetrachoric correlation scatter.hist Draw a scatter plot with associated X and Y histograms, densitie and correlation setCor Set Correlation and Multiple Regression from matrix or raw input structure.diagram Draw a structural equation model specified by two measurement models and a structural model sim.anova Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures. structure.list Create factor model matrices from an input list fa.sort Sort factor analysis or principal components analysis loadings Tucker 9 Cognitive variables discussed by Tucker and Lewis (1973) tr Find the trace of a square matrix Harman.political Eight political variables used by Harman (1967) as example 8.17 Harman Two data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt KMO Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy lowerUpper Combine two square matrices to have a lower off diagonal for one, upper off diagonal for the other omega.graph Graph hierarchical factor structures fa.diagram Graph factor loading matrices error.dots Show a dot.chart with error bars for different groups or variables galton Galton's Mid parent child height data irt.item.diff.rasch Simple function to estimate item difficulties using IRT concepts geometric.mean Find the geometric mean of a vector or columns of a data.frame. iqitems 16 multiple choice IQ items partial.r Find the partial correlations for a set (x) of variables with set (y) removed. neo NEO correlation matrix from the NEO_PI_R manual multi.hist Multiple histograms with density and normal fits on one page peas Galtons Peas predict.psych Prediction function for factor analysis or principal components principal Principal components analysis (PCA) 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. withinBetween An example of the distinction between within group and between group correlations omega Calculate McDonald's omega estimates of general and total factor saturation Schutz The Schutz correlation matrix example from Shapiro and ten Berge score.alpha Score scales and find Cronbach's alpha as well as associated statistics scoreIrt Find Item Response Theory (IRT) based scores for dichotomous or polytomous items sim.structure Create correlation matrices or data matrices with a particular measurement and structural model cor.wt The sample size weighted correlation may be used in correlating aggregated data VSS.plot Plot VSS fits VSS.parallel Compare real and random VSS solutions sim.item Generate simulated data structures for circumplex, spherical, or simple structure cor2dist Convert correlations to distances (necessary to do multidimensional scaling of correlation data) dfOrder Sort (order) a dataframe or matrix by multiple columns df2latex Convert a data frame, correlation matrix, or factor analysis output to a LaTeX table dummy.code Create dummy coded variables Dwyer 8 cognitive variables used by Dwyer for an example. factor.model Find R = F F' + U2 is the basic factor model ICC Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss) heights A data.frame of the Galton (1888) height and cubit data set. Harman.8 Correlations of eight physical variables (from Harman, 1966) factor.residuals R* = R- F F' Harman.5 5 socio-economic variables from Harman (1967) irt.responses Plot probability of multiple choice responses as a function of a latent trait irt.1p Item Response Theory estimate of theta (ability) using a Rasch (like) model mixed.cor Find correlations for mixtures of continuous, polytomous, and dichotomous variables matrix.addition A function to add two vectors or matrices paired.r Test the difference between (un)paired correlations residuals.psych Extract residuals from various psych objects print.psych Print and summary functions for the psych class Promax Perform bifactor, promax or targeted rotations and return the inter factor angles. reverse.code Reverse the coding of selected items prior to scale analysis pairs.panels SPLOM, histograms and correlations for a data matrix scoreItems Score item composite scales and find Cronbach's alpha, Guttman lambda 6 and item whole correlations score.multiple.choice Score multiple choice items and provide basic test statistics simulation.circ Simulations of circumplex and simple structure sim.VSS create VSS like data tetrachoric Tetrachoric, polychoric, biserial and polyserial correlations from various types of input thurstone Thurstone Case V scaling VSS.scree Plot the successive eigen values for a scree test winsor Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame No Results!