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

Description Usage Arguments Value Author(s) See Also Examples

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

1 2	## S3 method for class 'aldmck' predict(object, caliper=0.2, ...)

`object`	A `aldmck` output object.
`caliper`	Caliper tolerance. Any individuals with estimated weights lower than this value are NA'd out for prediction. Since predictions are made by dividing observed values by estimating weights, very small weights will grossly inflate the magnitude of predicted values and lead to extreme predictions.
`...`	Ignored.

A matrix of predicted values generated from the parameters estimated from a aldmck 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

'aldmck', 'LC1980'

## Estimate an aldmck object from example and call predict function
data(LC1980)
result <- aldmck(data=LC1980, polarity=2, respondent=1, missing=c(0,8,9),verbose=TRUE)
prediction <- predict.aldmck(result)

## Examine predicted vs. observed values for first 10 respondents
## Note some observations are NA'd in prediction matrix from caliper
## 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")