Measurement Error Quartet (based on Michael Friendly's post)

readme.md

Measurement Error Quartet.R

library(tidyverse)
library(patchwork)
library(glue)

set.seed(7)

data = tibble(
  x = rnorm(50, 5),
  y = x + rnorm(50, 0, .7),
  x_noise = x + rnorm(50, 0, 1),
  y_noise = y + rnorm(50, 0, 1)
)

cor_no_no   = cor.test(data$x, data$y)
cor_no_yes  = cor.test(data$x, data$y_noise)
cor_yes_no  = cor.test(data$x_noise, data$y)
cor_yes_yes = cor.test(data$x_noise, data$y_noise)


ggplot(data) +
  aes(x=x, y=y) +
  geom_point(size=2, alpha = 0.5) +
  geom_smooth(method = "lm", color="red", fill="red", fullrange = TRUE) +
  expand_limits(x = c(1, 9), y = c(1, 9)) +
  coord_cartesian(xlim = c(1, 9), ylim = c(1, 9)) +
  theme_minimal() + 
  labs(title = glue("none\nr = {round(cor_no_no$estimate, 2)} [{round(cor_no_no$conf.int[[1]], 2)}, {round(cor_no_no$conf.int[[2]], 2)}]")) +
ggplot(data) +
  aes(x=x, y=y_noise) +
  geom_point(size=2, alpha = 0.5) +
  geom_smooth(method = "lm", color="red", fill="red", fullrange = TRUE) +
  expand_limits(x = c(1, 9), y = c(1, 9)) +
  coord_cartesian(xlim = c(1, 9), ylim = c(1, 9)) +
  theme_minimal() +
  labs(title = glue("y noise\nr = {round(cor_no_yes$estimate, 2)} [{round(cor_no_yes$conf.int[[1]], 2)}, {round(cor_no_yes$conf.int[[2]], 2)}]")) +
ggplot(data) +
  aes(x=x_noise, y=y) +
  geom_point(size=2, alpha = 0.5) +
  geom_smooth(method = "lm", color="red", fill="red", fullrange = TRUE) +
  expand_limits(x = c(1, 9), y = c(1, 9)) +
  coord_cartesian(xlim = c(1, 9), ylim = c(1, 9)) +
  theme_minimal() +
  labs(title = glue("x noise\nr = {round(cor_yes_no$estimate, 2)} [{round(cor_yes_no$conf.int[[1]], 2)}, {round(cor_yes_no$conf.int[[2]], 2)}]")) +
ggplot(data) +
  aes(x=x_noise, y=y_noise) +
  geom_point(size=2, alpha = 0.5) +
  geom_smooth(method = "lm", color="red", fill="red", fullrange = TRUE) +
  expand_limits(x = c(1, 9), y = c(1, 9)) +
  coord_cartesian(xlim = c(1, 9), ylim = c(1, 9)) +
  theme_minimal() +
  labs(title = glue("x and y noise\nr = {round(cor_yes_yes$estimate, 2)} [{round(cor_yes_yes$conf.int[[1]], 2)}, {round(cor_yes_yes$conf.int[[2]], 2)}]"))