qualityTools (version 1.31.1)

steepAscent: Steepest Ascent

Description

steepAscent is a method to calculate the steepest ascent for a facDesign object

Usage

steepAscent(factors, response, size = 0.2, steps = 5, data)

Arguments

factors

list - vector of factor names (coded) to be included in calculation, first factor is reference factor

response

character - response given in data

size

numeric - step size in coded units for the first factor given in factors

steps

integer - number of steps

data

fdo - an object of class facDesign

Value

• an object of class steepAscent

Details

A first order model is fitted for the factors given in factors. Based on the step size given the steepest ascent is calculated.

References

http://www.itl.nist.gov/div898/handbook/pri/section5/pri5311.htm

See Also

desires for multiple response optimization usign desirabilities.

Examples

#Example from References
fdo = facDesign(k = 2, centerCube = 5)
lows(fdo) = c(170, 150)
highs(fdo) = c(230, 250)
names(fdo) = c("temperature", "time")
units(fdo) = c("C", "minutes")
yield = c(32.79, 24.07, 48.94, 52.49, 38.89, 48.29, 29.68, 46.5, 44.15)
response(fdo) = yield
summary(fdo)

sao = steepAscent(factors = c("B", "A"), response = "yield", size = 1, data = fdo)
sao
obs.yield = c(NA, 56.2, 71.49, 75.63, 72.31, 72.10)
response(sao) = obs.yield
plot(sao, type = "b", col = 2, main = "Steepest Ascent")