lme4版本1.1-7的迭代次数增加

Question

我在尝试使用包glmer版本1 / 1-7的lme4函数进行混合效果二项回归时遇到迭代问题。

当我使用代码运行模型时：

model <- glmer(Clinical.signs ~ cloacal +(1|Chicken_ID), family = binomial, 
               data = viral_load_9)

我收到警告：

  

错误：pwrssUpdate未收敛（maxit）迭代

当我按照here

给出的建议时

使用代码：

model <- glmer(Clinical.signs ~ cloacal +(1|Chicken_ID), family = binomial, 
               data = viral_load_9, 
               control=glmerControl(optimizer="bobyqa", 
                                    optCtrl = list(maxfun = 100000)))

我仍然有完全相同的错误消息。

我们将非常感激地收到有关我的代码可能出现的问题的任何建议。

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遵循aosmith的建议（感谢您的建议！）我包含数据和代码，以便其他人可以复制我得到的结果。请注意，代码适用于变量“oral”并生成“model_1”，但是当我使用变量“cloacal”运行它时，我收到了如上所述的错误消息。

Chicken_ID  <- c(44,44,45,45,46,46,47,47,48,48,49,49,50,50,51,51,52,52,53,55,55)
oral <- c(-0.4827578,-0.1845839,-1.3772797,-0.7809318,-0.4827578,1.6044598,0.1135901,0.411764,-0.1845839,1.6044598,-0.1845839,1.6044598,-1.6754536,0.709938,-1.0791057,0.709938,0.1135901,1.0081119,0.411764,-1.6754536,-0.1845839)
cloacal <- c(-0.9833258,0.450691,-1.1267275,0.7374944,-1.1267275,1.0242977,-1.5569325,1.0242977,0.3072893,1.0242977,-0.1229157,1.1676994,-1.5569325,0.5940927,0.450691,0.3072893,-1.1267275,0.7374944,0.1638876,-1.5569325,1.1676994)
clinical.signs  <- c("YES","YES","NO","YES","NO","YES","NO","YES","YES","YES","YES","YES","NO","YES","YES","YES","NO","YES","YES","NO","YES")
clinical.signs <- factor(clinical.signs)
viral_load <- data.frame(Chicken_ID, oral, cloacal, clinical.signs)


library(lme4)

model_1 <- glmer(clinical.signs ~ oral +(1|Chicken_ID), 
                       family = binomial, data = viral_load)
summary(model_1)

model_2 <- glmer(clinical.signs ~ cloacal +(1|Chicken_ID), 
                       family = binomial, data = viral_load)

Answer 1

您的代码可能不是问题。见Q on Cross-Validated。 您可以采取一些措施来防止收敛失败：

• 重新调整连续变量
• 使用glmerControl()
尝试不同的近似值
• 检查数据是否有稀疏数据。如果在某些预测变量水平上没有足够的结果或观察结果，则该模型可能无法收敛。