missing-data.R
In visreg: Visualization of Regression Models

# Tests missing / subsetted data in various / mixed locations
if (interactive()) {library(tinytest); devtools::load_all(quiet=TRUE)}

ozone <- airquality
fit <- lm(Ozone ~ Solar.R, data=ozone)
visreg(fit, "Solar.R") |> expect_silent()

x <- rnorm(nrow(ozone))
x[sample(1:nrow(ozone),20)] <- NA
fit <- lm(Ozone ~ Solar.R + x, data=ozone)
visreg(fit, "Solar.R")
visreg(fit, "x")

fit <- lm(Ozone ~ I(Solar.R^2) + Wind, data=ozone)
visreg(fit,"Solar.R")

fit <- lm(log(Ozone) ~ Solar.R + Wind + I(Temp^2), data=ozone)
visreg(fit,"Wind", trans=exp)

y <- rnorm(100)
x <- rnorm(100)
x[c(10,20)] <- NA
fit <- lm(y ~ x)
visreg(fit, "x")

# Subset
fit <- lm(Ozone ~ Wind, data=airquality)
visreg(fit, ylim=c(-50, 200))
fit <- lm(Ozone ~ Wind, data=airquality, subset=(Ozone < 150))
visreg(fit, ylim=c(-50, 200))
fit <- lm(Ozone ~ Wind, data=airquality)
visreg(fit, ylim=c(-50, 200), type="contrast")
fit <- lm(Ozone ~ Wind, data=airquality, subset=(Ozone < 150))
visreg(fit, ylim=c(-50, 200), type="contrast")

# A bunch of mixed types in various locations
a <- rep(LETTERS[1:4],25)
b <- rep(c(TRUE, FALSE), 50)
df <- data.frame(c=rnorm(100), d=factor(rep(1:10,10)), y=rnorm(100))
fit <- lm(y~a+b+c+d, df)
op <- par(mfrow=c(2,2))
visreg(fit)
par(op)

# Data not in global scope
myFun <- function(form) {
  Data <- data.frame(x=rnorm(100), y=rnorm(100), z=rnorm(100))
  fit <- lm(form, data=Data)
  if (interactive()) print(environment())
  if (interactive()) print(environment(fit$terms))
  visreg(fit)
  visreg2d(fit, "x", "y")
}
myFun(z ~ x + y)

# Data in a package namespace
fit <- lm(accel ~ times, data = MASS::mcycle)
visreg(fit, "times")

# Missing factor levels
x <- factor(rep(LETTERS[1:5], rep(5, 5)))
y <- rnorm(length(x))
y[11:15] <- NA
fit <- lm(y ~ x)
visreg(fit)
visreg(fit, type='contrast')

# data options
data("birthwt", package="MASS")
TMP <- birthwt
fit <- lm(bwt ~ age + race, TMP)
rm(TMP)
visreg(fit, 'age', data=birthwt)
visreg2d(fit, 'age', 'race', data=birthwt)
fit$data <- birthwt
visreg(fit, 'age')