Chwirut1 {NISTnls} | R Documentation |
The Chwirut1
data frame has 214 rows and 2 columns giving
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.
Try <- function(expr) if (!inherits(val <- try(expr), "try-error")) val plot(y ~ x, data = Chwirut1) Try(fm1 <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut1, trace = TRUE, start = c(b1 = 0.1, b2 = 0.01, b3 = 0.02))) Try(fm1a <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut1, 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 = Chwirut1, trace = TRUE, start = c(b1 = 0.15, b2 = 0.008, b3 = 0.010))) Try(fm2a <- nls(y ~ exp(-b1*x)/(b2+b3*x), data = Chwirut1, trace = TRUE, start = c(b1 = 0.15, b2 = 0.008, b3 = 0.010), alg = "port")) Try(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")) Try(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"))