Chwirut1 {NISTnls}R Documentation

Ultrasonic calibration study 1

Description

The Chwirut1 data frame has 214 rows and 2 columns giving

Format

This data frame contains the following columns:

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

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

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")

[Package Contents]