Chwirut2 {NISTnls} | R Documentation |
The Chwirut2
data frame has nr rows and nc columns giving
y |
A numeric vector of ultrasonic response values. |
x |
A numeric vector of metal distance values. |
This data frame contains the following columns:
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.
Chwirut, D., NIST (197?). Ultrasonic Reference Block Study.
library(NISTnls) data(Chwirut2) plot(y ~ x, data = Chwirut2) fm1 <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.1 , b2 = 0.01, b3 = 0.02) ) fm2 <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.15 , b2 = 0.008, b3 = 0.01) ) fm3 <- nls(y ~ exp(-b1*x)/(1+p3*x), data = Chwirut2, trace = TRUE, start = c(b1 = 0.1, p3 = 2.), alg = "plinear" ) 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" )