Check for NAs in Initial Row By ID

The function checks if there are missing values for the initial row by ID.

Usage

InitialNA(data, id, time, observed, covariates = NULL, ncores = NULL)

Arguments

data

Data frame. A data frame object of data for potentially multiple subjects that contain a column of subject ID numbers (i.e., an ID variable), a column indicating subject-specific measurement occasions (i.e., a TIME variable), at least one column of observed values.

id

Character string. A character string of the name of the ID variable in the data.

time

Character string. A character string of the name of the TIME variable in the data.

observed

Character vector. A vector of character strings of the names of the observed variables in the data.

covariates

Character vector. A vector of character strings of the names of the covariates in the data.

ncores

Positive integer. Number of cores to use. If ncores = NULL, use a single core. Consider using multiple cores when number of individuals is large.

Value

Returns a vector of ID numbers where the initial row has any missing value.

See also

Other Dynamic Modeling Utility Functions: DeleteInitialNA(), InsertNA(), ScaleByID(), SubsetByID()

Author

Ivan Jacob Agaloos Pesigan

Examples

# prepare parameters
set.seed(42)
## number of individuals
n <- 5
## time points
time <- 5
## dynamic structure
p <- 3
mu0 <- rep(x = 0, times = p)
sigma0 <- 0.001 * diag(p)
sigma0_l <- t(chol(sigma0))
alpha <- rep(x = 0, times = p)
beta <- 0.50 * diag(p)
psi <- 0.001 * diag(p)
psi_l <- t(chol(psi))

library(simStateSpace)
ssm <- SimSSMVARFixed(
  n = n,
  time = time,
  mu0 = mu0,
  sigma0_l = sigma0_l,
  alpha = alpha,
  beta = beta,
  psi_l = psi_l,
  type = 0
)
data <- as.data.frame(ssm)
# Replace first row with NA
data[1, paste0("y", 1:p)] <- NA
InitialNA(
  data = data,
  id = "id",
  time = "time",
  observed = paste0("y", 1:p),
)
#> [1] 1