lerp: Linear interpolation

In BAAQMD/qtytools: Parse, Manipulate, and Predict Quantities

Linear interpolation

Description

Linear interpolation

Usage

lerp(object, ...)

## Default S3 method:
lerp(
  object,
  x = NULL,
  xout = NULL,
  nm = FALSE,
  extrapolate = FALSE,
  ...,
  verbose = getOption("verbose")
)

## S3 method for class 'lerp'
predict(
  object,
  envir = NULL,
  method = "linear",
  extrapolate = FALSE,
  ...,
  verbose = getOption("verbose")
)

Arguments

object	(see Details) must contain values to be interpolated
...	further arguments passed to stats::approx()
x	(vector) x-coords; if not supplied, values to be interpolated are assumed to be evenly spaced
xout	(numeric) points at which to make predictions
verbose	(logical) display messages

Details

Names may be assigned to the resulting vector. If nm is FALSE, then no names will be assigned.

Methods (by class)

• default: replace NAs with interpolated values

• lerp: calculate values using a formula

Examples

year <- c(1991, 1993, 1995, 1998)
sales <- c(21, NA, 40, 45)
sales_model <- lerp(sales ~ year, data = data.frame(year, sales))

lerp(sales)
lerp(sales, year)

predict(sales_model, tibble::tibble(year = 1990:2000))
predict(sales_model, tibble::tibble(year = 1990:2000), extrapolate = TRUE)

BAAQMD/qtytools documentation built on June 30, 2022, 6:07 p.m.