create control code for ICLUST graphical output
cluster Fit: fit of the cluster model to a correlation matrix
Simulate a congeneric data set
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.
Scree plots of data or correlation matrix compared to random ``parallel" matrices
Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
Compare real and random VSS solutions
25 Personality items representing 5 factors
Basic summary statistics by group
Galton's example of the relationship between height and 'cubit' or forearm length
Graph factor loading matrices
Apply the Very Simple Structure and MAP criteria to determine the appropriate number of factors.
Item Response Theory estimate of theta (ability) using a Rasch (like) model
A function to add two vectors or matrices
Simulations of circumplex and simple structure
Create a keys matrix for use by score.items or cluster.cor
Find the harmonic mean of a vector, matrix, or columns of a data.frame
ICLUST: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
Fisher r to z and z to r and confidence intervals
Count number of pairwise cases for a data set with missing (NA) data.
Find the Standard deviation for a vector, matrix, or data.frame - do not return error if there are no cases
Find the probability of replication for an F, t, or r and estimate effect size
Generate simulated data structures for circumplex or simple structure
Combine calls to head and tail
How well does the factor model fit a correlation matrix. Part of the VSS package
Create a population or sample correlation matrix, perhaps with hierarchical structure.
Sort items by absolute size of cluster loadings
Convert a phi coefficient to a polychoric correlation
Create demo data for psychometrics
Find the phi coefficient of correlation between two dichotomous variables
Principal components analysis
Function to form hierarchical cluster analysis of items
Calculate the omega estimate of factor saturation
Plot data and 1 and 2 sigma correlation ellipses
Plotting functions for the psych package of class ``psych"
Function to convert scores to ``conventional
" metrics
Find R = F F' + U2 is the basic factor model
Testing of functions in the psych package
Score scales and find Cronbach's alpha as well as associated statistics
Find dis-attenuated correlations and give alpha reliabilities
Coefficient of factor congruence
Find polychoric correlations of item data
Plot a scree test
Alternative estimates of test reliabiity
Find the geometric mean of a vector or columns of a data.frame.
Graph hierarchical factor structures
Find the trace of a square matrix
Kurtosis of a vector, matrix, or data frame
Plot factor/cluster loadings and assign items to clusters by their highest loading.
Draw an ICLUST graph using the Rgraphviz package
Apply the Schmid Leiman transformation to a correlation matrix
R* = R- F F'
Score item composite scales and find Cronbach's alpha as well as associated statistics
``Hand" rotate a factor loading matrix
Intraclass Correlations (ICC1, ICC2, ICC3 from Shrout and Fleiss)
Multiple Regression from matrix input
3 Measures of ability: SATV, SATQ, ACT
create VSS like data
Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
Print and summary functions for the psych class
Find Cohen's kappa and weighted kappa coefficients for correlation of two raters
Test the difference between (un)paired correlations
Convert a table with counts to a matrix or data.frame representing those counts.
Find correlations of composite variables from a larger matrix
Plot means and confidence intervals for multiple groups
Convert base rates of two diagnoses and their comorbidity into phi, Yule, and tetrachorics
Galton`s Peas
Find the Squared Multiple Correlation (SMC) of each variable with the remaining variables in a matrix
shortcut for reading from the clipboard
Multiple histograms with density and normal fits on one page
A package for personality, psychometric, and psychological research
Find item by cluster correlations, corrected for overlap and reliability
Principal Axis Factor Analysis
Distances between 11 US cities
Plot x and y error bars
Convert a cluster vector (from e.g., kmeans) to a keys matrix suitable for scoring item clusters.
Apply four tests of circumplex versus simple structure
Plot means and confidence intervals
13 personality scales from the Eysenck Personality Inventory and Big 5 inventory
Plot VSS fits
Phi or Yule coefficient matrix to polychoric coefficient matrix
Extract cluster definitions from factor loadings
Tests of significance for correlations
Galton's Mid parent child height data
SPLOM, histograms and correlations for a data matrix
Find the partial correlations for a set (x) of variables with set (y) removed.
Find the Winsorized scores or means for a vector, matrix, or data.frame
Cronbach alpha for a scale
A data.frame of the Galton (1888) height and cubit data set.
Simple function to estimate item difficulties using IRT concepts
Test the adequacy of simple choice, logistic, or Thurstonian scaling.
Score multiple choice items and provide basic test statistics
Paired comparison of preferences for 9 vegetables
Bartlett's test that a correlation matrix is an identity matrix
Basic descriptive statistics useful for psychometrics
14 multiple choice IQ items
Chi square test of whether a single matrix is an identity matrix, or a pair of matrices are equal.
Convert Cartesian factor loadings into polar coordinates
Calculate skew for a vector, matrix, or data.frame
Thurstone Case V scaling