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