library(latticeExtra)# all trees except 4 have R squared >= 0.97is.highR2 <- function(tree)  summary(lm(age ~ circumference, Orange, subset = Tree == tree))$r.squared >= 0.97Trees <- Filter(is.highR2, levels(Orange$Tree)); Trees## [1] "3" "1" "5" "2"if (length(Trees)) {  p1 <- xyplot(age ~ circumference | Tree, Orange, subset = Tree %in% Trees) +     layer(panel.ablineq(lm(y ~ x), r.squared = TRUE, label = "", sep = "", adj = c(0.75, -4)))   plot(p1)}##################################################################library(broom)library(dplyr)library(ggplot2)library(ggpmisc)# all Trees except 4 have R squared >= 0.97Trees <- Orange %>%  nest_by(Tree) %>%  summarize(model = list(lm(age ~ circumference, data)), glance(model)) %>%  filter(r.squared >= 0.97) %>%  pull(Tree)# plotif (length(Trees)) {  p2 <- Orange %>%    filter(Tree %in% Trees) %>%    ggplot(aes(circumference, age)) +      geom_point() +      stat_poly_eq() +      geom_smooth(method = "lm", se = FALSE) +      facet_wrap(~ Tree)  plot(p2) }