add big-pred example to misc

misc/lme4_bigpred.R

@@ -0,0 +1,40 @@
+library(lme4)
+print(packageVersion("Matrix"))
+m1 <- lmer(Reaction 1~ Days + (Days|Subject), data = sleepstudy)
+predict(m1, newdata = sleepstudy, se.fit = TRUE)
+simulate(~Days + (Days|Subject),
+         newdata = sleepstudy,
+         newparams = list(beta = c(250, 1),
+                          theta = c(1, 1, 1),
+                          sigma = 1),
+         family = gaussian)
+
+set.seed(101)
+dd <- expand.grid(id = factor(1:1000), year = 1:15)
+d_age <- data.frame(id = factor(1:1000),
+                    age0 = sample(20:50, size = 1000, replace= TRUE))
+dd2 <- merge(dd, d_age, by = "id") |>
+    transform(age = age0 + year,
+              score = sample(1:50, size = nrow(dd), replace = TRUE))
+form <- adl~I(year^2)+score*year + age*year + (1+year|id)
+colnames(X <- model.matrix(nobars(form[-2]), data = dd2))
+beta_vec <- c(20, 0.1, 0.5, 1, 1, 0.5, 0.5)
+stopifnot(ncol(X) == length(beta_vec))
+dd2$adl <- simulate(form[-2],
+                    newdata = dd2,
+                    newparams = list(beta = beta_vec,
+                                     theta = c(2, 0.1, 0),
+                                     sigma = 1),
+                    family = gaussian)[[1]]
+
+fit <- lmer(form, data = dd2)
+
+pred.dd <- expand.grid(age = 50:100, year = 1:15,
+                       score = seq(min(dd2$score), max(dd2$score), length.out=100), 
+                       id = sample(dd2$id, size = 10, replace = FALSE))
+
+pred <- predict(fit, newdata = pred.dd) ## OK
+pred <- predict(fit, newdata = pred.dd, se.fit = TRUE)
+
+pred <- predict(fit, newdata = pred.dd[sample(nrow(pred.dd), size = 1000,
+                                            replace = FALSE),], se.fit = TRUE)