Numerically integrates the non-normalised pdf or the detection function of observed distances over specified ranges.

Gradient of the integral of the detection function, i.e., d beta/d theta in the documentation. This gradient of the integral is the same as the integral of the gradient, thanks to Leibniz integral rule.

Usage

integratepdf.grad(
  par.index,
  ddfobj,
  int.range,
  width,
  standardize = FALSE,
  point = FALSE,
  left = 0,
  pdf.based = TRUE
)

Arguments

par.index: the index of the parameter of interest
ddfobj: the ddf object
int.range: vector with the lower and upper bound of the integration
width: the truncation width
standardize: TRUE if the non-standardised detection function should be integrated. Only implemented for standardize = FALSE, so users should not touch this argument and it can probably be removed.
point: are the data from point transects (TRUE) or line transects (FALSE).
left: the left truncation. Defaults to zero.
pdf.based: evaluate the non-normalised pdf or the detection function? Default is TRUE.

Details

For internal use only – not to be called by mrds or Distance users directly.

Author

Felix Petersma