A GAM of Furrycat’s data shows a strong relationship between health and both hardiness and dexterity.
model <- gam(
formula = health ~
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:
## health ~ 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) 7220.4688 0.3164 22824.003 <2e-16 ***
## armor -0.7493 0.9554 -0.784 0.433
## ---
## 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) 1.088 1.169 1.182e+07 <2e-16 ***
## s(fortitude) 1.000 1.000 5.140e-01 0.4737
## s(dexterity) 1.000 1.000 3.983e+05 <2e-16 ***
## s(endurance) 1.000 1.000 1.330e+00 0.2496
## s(intellect) 3.672 4.550 1.329e+00 0.2825
## s(cleverness) 1.000 1.000 6.630e-01 0.4159
## s(courage) 4.285 5.314 1.018e+00 0.4536
## s(dependability) 3.564 4.459 2.317e+00 0.0500 .
## s(power) 1.000 1.000 6.151e+00 0.0135 *
## s(fierceness) 1.000 1.000 3.228e+00 0.0731 .
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## R-sq.(adj) = 1 Deviance explained = 100%
## GCV = 28.576 Scale est. = 27.14 n = 410
And GAM shows a linear relationships.
plot(model, select = 1)
plot(model, select = 3)
The linear model shows high correlation and low residuals.
model <- lm(health ~ hardiness + dexterity, data = normalized_df)
summary(model)
##
## Call:
## lm(formula = health ~ hardiness + dexterity, data = normalized_df)
##
## Residuals:
## Min 1Q Median 3Q Max
## -8.4247 -4.7295 0.7966 4.3744 7.8303
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 42.118743 0.602538 69.9 <2e-16 ***
## hardiness 14.958346 0.002312 6469.0 <2e-16 ***
## dexterity 2.992504 0.002671 1120.5 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 5.309 on 407 degrees of freedom
## Multiple R-squared: 1, Adjusted R-squared: 1
## F-statistic: 8.835e+07 on 2 and 407 DF, p-value: < 2.2e-16
And looks like this.
The residuals suggest that some of the error may be due to rounding.
Health is roughly captured by the following formula, \(health \approx 42 + 15 * hardiness + 3 * dexterity\). The final health is rounded.