Predictions from a CPB fit

Usage

# S3 method for class 'cpb'
predict(
  object,
  newdata = NULL,
  type = c("response", "rate", "link", "ceiling", "prob"),
  at = NULL,
  offset = NULL,
  ...
)

Arguments

object: A "cpb" object.
newdata: Optional data frame of new covariate profiles; if omitted, the fitted data are used.
type: One of "response" (the exact mean of the fitted distribution; for a zero-truncated fit the conditional mean E(Y | Y >= 1)), "rate" (the CPB rate parameter lambda = exp(x'b), which equals the mean only when lambda/(1-alpha) is an integer), "link" (the linear predictor, log lambda), "ceiling" (the implied ceiling lambda/(1-alpha)), or "prob" (the probability that Y equals at).
at: For type = "prob", the count value(s) y whose probability is returned (length 1, or one per row of the prediction data).
offset: Optional offset (log scale) for the newdata branch: a numeric vector or a column name in newdata. For newdata = NULL the fit's own offset is used.
...: Unused.

Value

A numeric vector.

Examples

set.seed(1); x <- rnorm(300)
N <- pmax(round(exp(1.6 + 0.5 * x) / 0.5), 1); y <- rbinom(300, N, 0.5)
fit <- cpb(y ~ x, data = data.frame(y = y, x = x)[y > 0, ], se = "none")
predict(fit, newdata = data.frame(x = 0), type = "ceiling")
#>          
#> 9.543256 
predict(fit, newdata = data.frame(x = c(-1, 1)), type = "prob", at = 5)
#> [1] 0.08812504 0.05952484