Worksheets/Week3
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Part 1
A factorial experiment was run to investigate the settings that minimize the production of an unwanted side product. The two factors being investigated are called A and B for simplicity.
# A = additive at 20mL and 30mL for low and high levels
A = c(-1, +1, -1, +1)
# B = without (-) or with (+) baffles
B = c(-1, -1, +1, +1)
# Response y is the amount of side product formed, y [grams]
y = c(89, 268, 179, 448)
# Fit a linear model
model_siderxn = lm(y ~ A + B + A*B)
summary(model_siderxn)
# Uncomment this line if you run the code in RStudio
#library(pid)
# Comment this line if you run this code in RStudio
source('https://yint.org/contourPlot.R')
# See how the two factors affect the response:
contourPlot(model_siderxn)
interaction.plot(A, B, y)
interaction.plot(B, A, y)
# Make a prediction with this model:
xA = -1
xB = -1
y.hat = predict(model_siderxn, data.frame(A = xA, B = xB))
paste0('Predicted value is: ', y.hat, ' grams of side product.')
Part 2
Continuing from above, with 2 extra experimental points:
# A = additive at 20mL and 30mL for low and high levels
A = c(-1, +1, -1, +1, 0, 0)
# B = without (-) or with (+) baffles
B = c(-1, -1, +1, +1, -1, +1)
# Response y is the amount of side product formed, y [grams]
y = c(89, 268, 179, 448, 186, 300)
model_siderxn_cp <- lm(y ~ A + B + A*B)
summary(model_siderxn_cp)
# Uncomment this line if you run the code in RStudio
#library(pid)
# Comment this line if you run this code in RStudio
source('https://yint.org/contourPlot.R')
contourPlot(model_siderxn_cp)