# Chwirut2 {NISTnls}

Ultrasonic calibration data 2

### Description

The `Chwirut2`

data frame has nr rows and nc columns giving

### 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.

### Examples

Try <- function(expr) if (!inherits(val <- try(expr), "try-error")) val plot(y ~ x, data = Chwirut2) Try(fm1 <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.1 , b2 = 0.01, b3 = 0.02))) Try(fm1a <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.1 , b2 = 0.01, b3 = 0.02), alg = "port")) Try(fm2 <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.15 , b2 = 0.008, b3 = 0.01))) Try(fm2a <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.15 , b2 = 0.008, b3 = 0.01), alg = "port")) Try(fm3 <- nls(y ~ exp(-b1*x)/(1+p3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.1, p3 = 2.), alg = "plinear")) Try(fm4 <- nls(y ~ exp(-b1*x)/(1+p3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.15, p3 = 0.01/0.008), alg = "plinear"))

Documentation reproduced from package NISTnls, version 0.9-13. License: GPL (>= 2)