我正在努力理解和解释逻辑回归中的交互项。解释变量是temperature(分类的)、gonad weight(连续的)和nnd(连续的)。在简化模型下:
model2012nnd = glm(fullyspawned ~ temperature + gonad + nnd+gonad:nnd,
family=quasibinomial(link = logit), data=spaw)
summary(model2012nnd)
#
# Call:
# glm(formula = fullyspawned ~ temperature + gonad + nnd + gonad:nnd,
# family = quasibinomial(link = logit), data = spaw)
#
# Deviance Residuals:
# Min 1Q Median 3Q Max
# -1.6793 -0.3594 -0.2457 -0.0651 2.5984
#
# Coefficients:
# Estimate Std. Error t value Pr(>|t|)
# (Intercept) 2.6262 2.1212 1.238 0.217638
# temperature15.58928019 2.4317 0.6453 3.768 0.000237 ***
# gonad -1.5718 0.6597 -2.382 0.018466 *
# nnd -2.4845 1.0782 -2.304 0.022593 *
# gonad:nnd 0.6407 0.3124 2.051 0.042058 *
# ---
# Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
#
# (Dispersion parameter for quasibinomial family taken to be 0.7864476)
#
# Null deviance: 118.652 on 152 degrees of freedom
# Residual deviance: 79.596 on 148 degrees of freedom
# AIC: NA
我如何解释这种互动?我将变量设置gonad为三个类别(低、中和高),并绘制了每个级别在温度 1 和 2 下完全产卵的概率,以尝试了解输出。这个对吗?