Create a covariance block matrix

Usage

get_cov_matrix(
  params,
  keep_all = FALSE,
  triangle = FALSE,
  nonmem = TRUE,
  limit = 0.001
)

params: parameters, a vector of standard deviations and correlations, e.g. list("CL" = 0.1, "V" = 0.2, "KA" = 0.3, "CL~V" = 0.3).
keep_all: Should all parameters be kept in the covariance matrix, even if they do not have a correlation with other parameters?
triangle: return the lower triangle as a vector instead of a matrix object?
limit: lower limit, to avoid becoming zero, which is not allowed by NONMEM (A COVARIANCE IS ZERO, BUT THE BLOCK IS NOT A BAND MATRIX.)

if (FALSE) { # \dontrun{
make_cov_matrix(list("CL" = 0.1, "V" = 0.2, "KA" = 0.3, "CL~V" = 0.3))
} # }