get_fderiv: Calculate First Derivative and Confidence Intervals for GAM...

In pbs-assess/gfsynopsis: Data Synopsis Reports for PBS Groundfish

Calculate First Derivative and Confidence Intervals for GAM Smooth Terms

Description

This function calculates the first derivatives and confidence intervals for specified smooth terms in a generalized additive model (GAM) using central difference approximations. It provides point estimates and confidence intervals for the derivatives of the specified terms.

Usage

get_fderiv(
  gam_object,
  newdata,
  terms,
  term_columns,
  x,
  h = 0.005,
  nsim,
  level = 0.95
)

Arguments

gam_object	A fitted GAM model.
newdata	A data frame containing the values of predictor variables to calculate the derivative.
terms	A character vector specifying the smooth terms for which derivatives are calculated.
term_columns	A character vector specifying the columns in 'newdata' that correspond to the terms specified in 'terms'.
x	Name of the predictor variable with respect to which you want to calculate the derivatives.
h	Step size for the central difference approximation (default = 0.005)
nsim	The number of simulations used to estimate confidence intervals.
level	Confidence level for the intervals (default is 0.95).

Value

A tibble with the following columns:

• smooth: Name of the smooth term.

• newdata: Values of the corresponding term in 'newdata'.

• derivative: Point estimate of the derivative.

• se: Standard error of the estimate.

• crit: Critical value for the confidence interval.

• lower: Lower bound of the confidence interval.

• upper: Upper bound of the confidence interval.

pbs-assess/gfsynopsis documentation built on March 26, 2024, 7:30 p.m.