emp_deriv: Estimate of empirical derivative based on sequence of... In HDCurves: Hierarchical Derivative Curve Estimation

 emp_deriv R Documentation

Estimate of empirical derivative based on sequence of quotient differences.

Description

`emp_deriv` Provides an estimate of an empirical derivative curve using one of the two sequence of quotient differences detailed in Page, Rodriguez-Alvarez, Lee (2020).

Usage

``````emp_deriv(y, t, D, u, ztype = 0)
``````

Arguments

 `y` numeric vector (response variable). `t` numeric vector (time variable). `D` integer indicating the bin width when estimating empirical derivatives `u` real indicating the bandwidth with regards to smoothing when estimating empirical derivatives. `ztype` integer indicating which sequence of empirical derivatives will be employed. (`0` indicates that which is parameterized by D and u while `1` indicates that which is parametrized by u)

Value

A vector of the same length as the input variable "y" that contains empirical derivative estimates for each entry of "y".

References

Page, G. L.; Rodriguez-Alvarez, M. X.; Lee, DJ; (2020) “Bayesian Hierarchical Modeling of Growth Curve Derivatives via Sequences of Quotient Differences” Journal of the Royal Statistical Society: Series C 69(2) 459-481

Examples

``````
# Our R-package
library(HDCurves)

data(growth)

y <- growth\$hgtm[,1]
t <- growth\$age

fprime <- emp_deriv(y=y, t=t, D=10, u=1, ztype=0)

plot(t,y, type="b")
plot(t, fprime, type="b")

``````

HDCurves documentation built on March 31, 2023, 10:08 p.m.