print.polycor function

Standard Methods for polycor Objects

Some standard methods for objects of class polycor, produced by polychor and polyserial, including print, summary, coef, and vcov. The summary method simply invokes the print method.

## S3 method for class 'polycor'
print(x, digits = max(3, getOption("digits") - 3), ...)
## S3 method for class 'polycor'
summary(object, ...)
## S3 method for class 'polycor'
coef(object, correlation=TRUE, thresholds=TRUE, ...)
## S3 method for class 'polycor'
vcov(object, correlation=TRUE, thresholds=TRUE, ...)

Arguments

• x, object: an object of class polycor, as returned by polychor

  or polyserial.

• digits: number of significant digits to be printed.

• correlation: return the estimated correlation or sampling variance of the correlation.

• thresholds: return the estimated thresholds or sampling variances/covariances of the thresholds.

• ...: pass arguments from summary to print; otherwise not used.

Author(s)

John Fox jfox@mcmaster.ca

See Also

polychor, polyserial

Examples

if(require(mvtnorm)){
    set.seed(12345)
    data <- rmvnorm(1000, c(0, 0), matrix(c(1, .5, .5, 1), 2, 2))
    x <- data[,1]
    y <- data[,2]
    cor(x, y) # sample correlation
    }
if(require(mvtnorm)){
    x <- cut(x, c(-Inf, .75, Inf))
    y <- cut(y, c(-Inf, -1, .5, 1.5, Inf))
    print(polychor(x, y, ML=TRUE, std.err=TRUE), 
      digits=3)  # polychoric correlation, ML estimate
    }
if(require(mvtnorm)){
    coef(polychor(x, y, ML=TRUE, std.err=TRUE))
    }
if(require(mvtnorm)){
    vcov(polychor(x, y, ML=TRUE, std.err=TRUE))
    }