Combine calls to head and tail
From a two by two table, find the Yule coefficient, convert to phi, or polychoric, recreate table the table to create the Yule coefficient.
Graph hierarchical factor structures
Create demo data for psychometrics
A package for personality, psychometric, and psychological research
Sort items by absolute size of cluster loadings
Function to form hierarchical cluster analysis of items
Score item composite scales and find Cronbach's alpha as well as associated statistics
Galton's Mid parent child height data
Plot a scree test
Apply the Very Simple Structure criterion to determine the appropriate number of factors.
Plot data and 1 and 2 sigma correlation ellipses
Simulations of circumplex and simple structure
Plot means and confidence intervals for multiple groups
Apply four tests of circumplex versus simple structure
Test the difference between (un)paired correlations
Multiple Regression from matrix input
create control code for ICLUST graphical output
25 Personality items representing 5 factors
Convert eigen vectors and eigen values to the more normal (for psychologists) component loadings
How well does the factor model fit a correlation matrix. Part of the VSS package
Find dis-attenuated correlations and give alpha reliabilities
Draw an ICLUST graph using the Rgraphviz package
Plot factor/cluster loadings and assign items to clusters by their highest loading
Plot x and y error bars
Calculate the omega estimate of factor saturation
Plot VSS fits
create VSS like data
ICLUST: Item Cluster Analysis -- Hierarchical cluster analysis using psychometric principles
Calculate skew for a vector, matrix, or data.frame
shortcut for reading from the clipboard
Compare real and random VSS solutions
Graph factor loading matrices
Scree plots of data or correlation matrix compared to random ``parallel" matrices
Item Response Theory estimate of theta (ability) using a Rasch (like) model
Find the phi coefficient of correlation between two dichotomous variables
Coefficient of factor congruence
Score scales and find Cronbach's alpha as well as associated statistics
Apply the Schmid Leiman transformation to a correlation matrix
Galton's example of the relationship between height and 'cubit' or forearm length
Find the harmonic mean of a vector, matrix, or columns of a data.frame
Find item by cluster correlations, corrected for overlap and reliability
Cronbach alpha for a scale
Count number of pairwise cases for a data set with missing (NA) data.
Generate simulated data structures for circumplex or simple structure
A data.frame of the Galton (1888) height and cubit data set.
Plot means and confidence intervals
``Hand" rotate a factor loading matrix
Fisher r to z and z to r and confidence intervals
Find the interpolated sample median, quartiles, or specific quantiles for a vector, matrix, or data frame
Extract cluster definitions from factor loadings
Find R = F F' + U2 is the basic factor model
Basic descriptive statistics useful for psychometrics
Principal Axis Factor Analysis
Find the geometric mean of a vector or columns of a data.frame.
Find correlations of composite variables from a larger matrix
Convert Cartesian factor loadings into polar coordinates
R* = R- F F'
Phi or Yule coefficient matrix to polychoric coefficient matrix
3 Measures of ability: SATV, SATQ, ACT
Galton`s Peas
Convert a phi coefficient to a polychoric correlation
Multiple histograms with density and normal fits on one page
Simple function to estimate item difficulties using IRT concepts
Find the probability of replication for an F, t, or r and estimate effect size
Create a population or sample correlation matrix with hierachical structure.
Tests of significance for correlations
Find polychoric correlations of item data
A function to add two vectors or matrices
Score multiple choice items and provide basic test statistics
Find the Winsorized mean for a vector, matrix, or data.frame
Convert a table with counts to a matrix or data.frame representing those counts.
14 multiple choice IQ items
Principal components analysis
Testing of functions in the psych package
Kurtosis of a vector, matrix, or data frame
cluster Fit: fit of the cluster model to a correlation matrix
Simulate a congeneric data set
Basic summary statistics by group
SPLOM, histograms and correlations for a data matrix
Function to convert scores to ``conventional
" metrics