predict.blackbt: Predict method of blackbt objects
In basicspace: Recovering a Basic Space from Issue Scales

Description Usage Arguments Value Author(s) See Also Examples

predict.blackbt reads an blackbt object and uses the estimates to generate a matrix of predicted values.

1 2	## S3 method for class 'blackbt' predict(object, dims=1, ...)

`object`	A `blackbox` output object.
`dims`	Number of dimensions used in prediction. Must be equal to or less than number of dimensions used in estimation.
`...`	Ignored.

A matrix of predicted values generated from the parameters estimated from a blackbt object.

Keith Poole ktpoole@uga.edu

Howard Rosenthal hr31@nyu.edu

Jeffrey Lewis jblewis@ucla.edu

James Lo lojames@usc.edu

Royce Carroll rcarroll@rice.edu

'blackbox_transpose', 'LC1980', 'LC1980_bbt'

## Estimate blackbt object from example and call predict function
data(LC1980)
data(LC1980_bbt)
prediction <- predict.blackbt(LC1980_bbt, dims=2)

## Examine predicted vs. observed values for first 10 respondents
## First column of LC1980 are self-placements, which are excluded
LC1980[1:10,-1]
prediction[1:10,]

## Check correlation across all predicted vs. observed, excluding missing values
prediction[which(LC1980[,-1] %in% c(0,8,9))] <- NA
cor(as.numeric(prediction), as.numeric(LC1980[,-1]), use="pairwise.complete")