# Kirby2: Microscope line width standards In NISTnls: Nonlinear least squares examples from NIST

## Description

The `Kirby2` data frame has 151 rows and 2 columns of data from an NIST study on scanning electron microscope line width standards.

## Format

This data frame contains the following columns:

y

A numeric vector of response values.

x

A numeric vector of input values.

## Details

These data are the result of a NIST study involving scanning electron microscope line with standards.

## Source

Kirby, R., NIST (197?). Scanning electron microscope line width standards.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24``` ```Try <- function(expr) if (!inherits(val <- try(expr), "try-error")) val plot(y ~ x, data = Kirby2) Try(fm1 <- nls(y ~ (b1 + b2*x + b3*x**2) / (1 + b4*x + b5*x**2), data = Kirby2, trace = TRUE, start = c(b1 = 2, b2 = -0.1, b3 = 0.003, b4 = -0.001, b5 = 0.00001))) Try(fm1a <- nls(y ~ (b1 + b2*x + b3*x**2) / (1 + b4*x + b5*x**2), data = Kirby2, trace = TRUE, alg = "port", start = c(b1 = 2, b2 = -0.1, b3 = 0.003, b4 = -0.001, b5 = 0.00001))) Try(fm2 <- nls(y ~ (b1 + b2*x + b3*x**2) / (1 + b4*x + b5*x**2), data = Kirby2, trace = TRUE, start = c(b1 = 1.5, b2 = -0.15, b3 = 0.0025, b4 = -0.0015, b5 = 0.00002))) Try(fm2a <- nls(y ~ (b1 + b2*x + b3*x**2) / (1 + b4*x + b5*x**2), data = Kirby2, trace = TRUE, alg = "port", start = c(b1 = 1.5, b2 = -0.15, b3 = 0.0025, b4 = -0.0015, b5 = 0.00002))) Try(fm3 <- nls(y ~ cbind(1, x, x**2)/(1 + x*(b4 + b5*x)), data = Kirby2, trace = TRUE, algorithm = "plinear", start = c(b4 = -0.001, b5 = 0.00001))) Try(fm4 <- nls(y ~ cbind(1, x, x**2)/(1 + x*(b4 + b5*x)), data = Kirby2, trace = TRUE, algorithm = "plinear", start = c(b4 = -0.0015, b5 = 0.00002))) ```

NISTnls documentation built on May 29, 2017, 3:49 p.m.