The GAM of Furrycat’s data shows a strong relationship between mind and both intellect and hardiness.
model <- gam(
formula = mind ~
s(hardiness) +
s(fortitude) +
s(dexterity) +
s(endurance) +
s(intellect) +
s(cleverness) +
s(courage) +
s(dependability) +
s(power) +
s(fierceness) +
armor,
family = gaussian(),
data = normalized_df
)
##
## Family: gaussian
## Link function: identity
##
## Formula:
## mind ~ s(hardiness) + s(fortitude) + s(dexterity) + s(endurance) +
## s(intellect) + s(cleverness) + s(courage) + s(dependability) +
## s(power) + s(fierceness) + armor
##
## Parametric coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 5011.4388 0.4553 11006.243 <2e-16 ***
## armor 0.8563 1.7452 0.491 0.624
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Approximate significance of smooth terms:
## edf Ref.df F p-value
## s(hardiness) 1.000 1.000 4.135e+05 <2e-16 ***
## s(fortitude) 5.253 6.035 1.703e+00 0.1225
## s(dexterity) 2.364 3.042 2.229e+00 0.0856 .
## s(endurance) 1.000 1.000 7.350e-01 0.3919
## s(intellect) 1.000 1.000 1.017e+07 <2e-16 ***
## s(cleverness) 2.908 3.467 1.079e+00 0.3780
## s(courage) 2.937 3.565 1.404e+00 0.2747
## s(dependability) 1.000 1.000 3.220e-01 0.5708
## s(power) 1.000 1.000 6.283e+00 0.0126 *
## s(fierceness) 1.000 1.000 8.900e-02 0.7657
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## R-sq.(adj) = 1 Deviance explained = 100%
## GCV = 26.894 Scale est. = 25.334 n = 370
And the GAM shows linear relationships.
plot(model, select = 5)
plot(model, select = 1)
The linear model shows high correlation and low residuals.
model <- lm(mind ~ intellect + hardiness, data = normalized_df)
summary(model)
##
## Call:
## lm(formula = mind ~ intellect + hardiness, data = normalized_df)
##
## Residuals:
## Min 1Q Median 3Q Max
## -8.7027 -4.3901 -0.7506 4.5294 8.4374
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 41.688608 0.708125 58.87 <2e-16 ***
## intellect 14.955890 0.001742 8587.93 <2e-16 ***
## hardiness 2.993651 0.001821 1643.66 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 5.139 on 367 degrees of freedom
## Multiple R-squared: 1, Adjusted R-squared: 1
## F-statistic: 7.177e+07 on 2 and 367 DF, p-value: < 2.2e-16
And looks like this.
The residuals suggest that some of the error may be due to rounding.
Mind is roughly captured by the following formula, \(mind \approx 42 + 15 * intellect + 3 * hardiness\).