# psych v1.3.10.12

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## Procedures for Psychological, Psychometric, and Personality Research

A number of routines for personality, psychometrics and experimental psychology. Functions are primarily for scale construction using factor 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 simulating 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 psychometrics as well as publications in personality research. For more information, see the personality-project.org/r webpage.

## Functions in psych

 Name Description cor.smooth Smooth a non-positive definite correlation matrix to make it positive definite cities Distances between 11 US cities bi.bars Draw pairs of bargraphs based on two groups epi.bfi 13 personality scales from the Eysenck Personality Inventory and Big 5 inventory dummy.code Create dummy coded variables Dwyer 8 cognitive variables used by Dwyer for an example. Gorsuch Example data set from Gorsuch (1997) for an example factor extension. factor.fit How well does the factor model fit a correlation matrix. Part of the VSS package ICC Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss) kaiser Apply the Kaiser normalization when rotating factors factor.stats Find various goodness of fit statistics for factor analysis and principal components Harman.5 5 socio-economic variables from Harman (1967) VSS.parallel Compare real and random VSS solutions irt.fa Item Response Analysis by Exploratory Factor Analysis of tetrachoric/polychoric correlations error.bars Plot means and confidence intervals errorCircles Two way plots of means, error bars, and sample sizes phi2tetra Convert a phi coefficient to a tetrachoric correlation ICLUST.rgraph Draw an ICLUST graph using the Rgraphviz package factor.rotate Hand" rotate a factor loading matrix fisherz Fisher r to z and z to r and confidence intervals cortest.mat Chi square tests of whether a single matrix is an identity matrix, or a pair of matrices are equal. Promax Perform bifactor, promax or targeted rotations and return the inter factor angles. fa.extension Apply Dwyer's factor extension to find factor loadings for extended variables cluster.loadings Find item by cluster correlations, corrected for overlap and reliability logistic Logistic transform from x to p and logit transform from p to x cluster2keys Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters. alpha Find two estimates of reliability: Cronbach's alpha and Guttman's Lambda 6. fa.parallel Scree plots of data or correlation matrix compared to random parallel" matrices error.crosses Plot x and y error bars Bechtoldt Seven data sets showing a bifactor solution. parcels Find miniscales (parcels) of size 2 or 3 from a set of items galton Galton's Mid parent child height data partial.r Find the partial correlations for a set (x) of variables with set (y) removed. iclust.diagram Draw an ICLUST hierarchical cluster structure diagram VSS.scree Plot the successive eigen values for a scree test blot Bond's Logical Operations Test -- BLOT cor.ci Bootstrapped confidence intervals for raw and composite correlations cor2dist Convert correlations to distances (necessary to do multidimensional scaling of correlation data) factor.scores Various ways to estimate factor scores for the factor analysis model cortest.bartlett Bartlett's test that a correlation matrix is an identity matrix circ.tests Apply four tests of circumplex versus simple structure Schmid 12 variables created by Schmid and Leiman to show the Schmid-Leiman Transformation cushny A data set from Cushny and Peebles (1905) on the effect of three drugs on hours of sleep, used by Student (1908) fa.sort Sort factor analysis or principal components analysis loadings error.bars.by Plot means and confidence intervals for multiple groups SD Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases lowerUpper Combine two square matrices to have a lower off diagonal for one, upper off diagonal for the other scaling.fits Test the adequacy of simple choice, logistic, or Thurstonian scaling. ellipses Plot data and 1 and 2 sigma correlation ellipses draw.tetra Draw a correlation ellipse and two normal curves to demonstrate tetrachoric correlation bock Bock and Liberman (1970) data set of 1000 observations of the LSAT iclust iclust: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles Tucker 9 Cognitive variables discussed by Tucker and Lewis (1973) spider Make "radar" or "spider" plots. cor.wt The sample size weighted correlation may be used in correlating aggregated data comorbidity Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics cubits Galton's example of the relationship between height and 'cubit' or forearm length set.cor Set Correlation and Multiple Regression from matrix or raw input score.alpha Score scales and find Cronbach's alpha as well as associated statistics VSS Apply the Very Simple Structure and MAP criteria to determine the appropriate number of factors. sim.structure Create correlation matrices or data matrices with a particular measurement and structural model factor.model Find R = F F' + U2 is the basic factor model predict.psych Prediction function for factor analysis or principal components Harman.political Eight political variables used by Harman (1967) as example 8.17 sim.congeneric Simulate a congeneric data set phi.demo A simple demonstration of the Pearson, phi, and polychoric corelation factor.residuals R* = R- F F' biplot.psych Draw biplots of factor or component scores by factor or component loadings tetrachoric Tetrachoric, polychoric, biserial and polyserial correlations from various types of input headTail Combine calls to head and tail block.random Create a block randomized structure for n independent variables Harman Two data sets from Harman (1967). 9 cognitive variables from Holzinger and 8 emotional variables from Burt describeBy Basic summary statistics by group VSS.plot Plot VSS fits cohen.kappa Find Cohen's kappa and weighted kappa coefficients for correlation of two raters eigen.loadings Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings sat.act 3 Measures of ability: SATV, SATQ, ACT matrix.addition A function to add two vectors or matrices mixed.cor Find correlations for mixtures of continuous, polytomous, and dichotomous variables fa.diagram Graph factor loading matrices mardia Calculate univariate or multivariate (Mardia's test) skew and kurtosis for a vector, matrix, or data.frame diagram Helper functions for drawing path model diagrams msq 75 mood items from the Motivational State Questionnaire for 3896 participants polychor.matrix Phi or Yule coefficient matrix to polychoric coefficient matrix glb.algebraic Find the greatest lower bound to reliability. scrub A utility for basic data cleaning and recoding. Changes values outside of minimum and maximum limits to NA. 00.psych A package for personality, psychometric, and psychological research omega.graph Graph hierarchical factor structures mat.sort Sort the elements of a correlation matrix to reflect factor loadings iqitems 16 multiple choice IQ items affect Two data sets of affect and arousal scores as a function of personality and movie conditions statsBy Find statistics (including correlations) within and between groups for basic multilevel analyses heights A data.frame of the Galton (1888) height and cubit data set. thurstone Thurstone Case V scaling count.pairwise Count number of pairwise cases for a data set with missing (NA) data. p.rep Find the probability of replication for an F, t, or r and estimate effect size interp.median Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame neo NEO correlation matrix from the NEO_PI_R manual harmonic.mean Find the harmonic mean of a vector, matrix, or columns of a data.frame tr Find the trace of a square matrix irt.item.diff.rasch Simple function to estimate item difficulties using IRT concepts test.psych Testing of functions in the psych package phi Find the phi coefficient of correlation between two dichotomous variables polar Convert Cartesian factor loadings into polar coordinates peas Galtons Peas winsor Find the Winsorized scores, means, sds or variances for a vector, matrix, or data.frame print.psych Print and summary functions for the psych class score.multiple.choice Score multiple choice items and provide basic test statistics rangeCorrection Correct correlations for restriction of range. (Thorndike Case 2) bfi 25 Personality items representing 5 factors sim.anova Simulate a 3 way balanced ANOVA or linear model, with or without repeated measures. paired.r Test the difference between (un)paired correlations residuals.psych Extract residuals from various psych objects plot.psych Plotting functions for the psych package of class psych" structure.list Create factor model matrices from an input list 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. simulation.circ Simulations of circumplex and simple structure mssd Find von Neuman's Mean Square of Successive Differences score.items Score item composite scales and find Cronbach's alpha, Guttman lambda 6 and item whole correlations factor2cluster Extract cluster definitions from factor loadings irt.1p Item Response Theory estimate of theta (ability) using a Rasch (like) model table2matrix Convert a table with counts to a matrix or data.frame representing those counts. score.irt Find Item Response Theory (IRT) based scores for dichotomous or polytomous items Harman.8 Correlations of eight physical variables (from Harman, 1966) read.clipboard shortcut for reading from the clipboard 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 ICLUST.graph create control code for ICLUST graphical output cor.plot Create an image plot for a correlation or factor matrix reverse.code Reverse the coding of selected items prior to scale analysis KMO Find the Kaiser, Meyer, Olkin Measure of Sampling Adequacy ICLUST.sort Sort items by absolute size of cluster loadings ICLUST.cluster Function to form hierarchical cluster analysis of items cluster.plot Plot factor/cluster loadings and assign items to clusters by their highest loading. describe Basic descriptive statistics useful for psychometrics sim Functions to simulate psychological/psychometric data. vegetables Paired comparison of preferences for 9 vegetables income US family income from US census 2008 make.keys Create a keys matrix for use by score.items or cluster.cor df2latex Convert a data frame, correlation matrix, or factor analysis output to a LaTeX table psych.misc Miscellaneous helper functions for the psych package rescale Function to convert scores to conventional " metrics burt 11 emotional variables from Burt (1915) cta Simulate the C(ues) T(endency) A(ction) model of motivation geometric.mean Find the geometric mean of a vector or columns of a data.frame. scatter.hist Draw a scatter plot with associated X and Y histograms, densitie and correlation sim.item Generate simulated data structures for circumplex, spherical, or simple structure guttman Alternative estimates of test reliabiity structure.diagram Draw a structural equation model specified by two measurement models and a structural model multi.hist Multiple histograms with density and normal fits on one page r.test Tests of significance for correlations cluster.cor Find correlations of composite variables from a larger matrix sim.hierarchical Create a population or sample correlation matrix, perhaps with hierarchical structure. cluster.fit cluster Fit: fit of the cluster model to a correlation matrix correct.cor Find dis-attenuated correlations given correlations and reliabilities fa Exploratory Factor analysis using MinRes (minimum residual) as well as EFA by Principal Axis, Weighted Least Squares or Maximum Likelihood factor.congruence Coefficient of factor congruence smc Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix superMatrix Form a super matrix from two sub matrices. corr.test Find the correlations, sample sizes, and probability values between elements of a matrix or data.frame. cosinor Functions for analysis of circadian or diurnal data irt.responses Plot probability of multiple choice responses as a function of a latent trait omega Calculate McDonald's omega estimates of general and total factor saturation pairs.panels SPLOM, histograms and correlations for a data matrix principal Principal components analysis (PCA) sim.VSS create VSS like data No Results!