Chwirut1 {NISTnls}R Documentation

Ultrasonic calibration study 1

Description

The Chwirut1 data frame has 214 rows and 2 columns giving

Arguments

y A numeric vector of ultrasonic response values
x A numeric vector or metal distance values

Format

This data frame contains the following columns:

Details

These data are the result of a NIST study involving ultrasonic calibration. The response variable is ultrasonic response, and the predictor variable is metal distance.

Source

Chwirut, D., NIST (197?). Ultrasonic Reference Block Study.

Examples

library(NISTnls)
data(Chwirut1)
plot(y ~ x, data = Chwirut1)
fm1 <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut1, trace = TRUE,
           start = c(b1 = 0.1, b2 = 0.01, b3 = 0.02))
fm2 <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut1, trace = TRUE,
           start = c(b1 = 0.15, b2 = 0.008, b3 = 0.010))
fm3 <- nls(y ~ exp(-b1*x)/(1+p3*x), data = Chwirut1, trace = TRUE,
           start = c(b1 = 0.1, p3 = 0.02/0.01), algorithm = "plinear")
fm4 <- nls(y ~ exp(-b1*x)/(1+p3*x), data = Chwirut1, trace = TRUE,
           start = c(b1 = 0.15, p3 = 0.01/0.008), algorithm = "plinear")