tests/testthat/test_graph_model.R

In reghelper: Helper Functions for Regression Analysis

context('graph_model function')


test_that('lm with 2 continuous int. works', {
    set.seed(123)
    x1 <- rnorm(100)
    
    set.seed(234)
    x2 <- rnorm(100)
    
    set.seed(345)
    y <- x1 * x2 + rnorm(100)
    
    model <- lm(y ~ x1 * x2)
    graph <- graph_model(model, y=y, x=x1, lines=x2)
    
    expect_is(graph, 'ggplot')
    expect_equal(length(graph$layers), 3)  # geom_point, geom_line, geom_errorbar
    
    expect_equal(ggplot2::quo_name(graph$mapping$x), 'x1')
    expect_equal(ggplot2::quo_name(graph$mapping$y), 'y')
    expect_equal(ggplot2::quo_name(graph$mapping$colour), 'x2')
    
    expect_equal(levels(graph$data$x1), c('-1 SD', '+1 SD'))
    expect_equal(levels(graph$data$x2), c('-1 SD', '+1 SD'))
})


test_that('lm with continuous x 2-level categorical int. works', {
    set.seed(123)
    x1 <- rnorm(100)
    
    x2 <- c(rep(0, 50), rep(1, 50))
    
    set.seed(345)
    y <- x1 * x2 + rnorm(100)
    
    x2 <- factor(x2)
    
    model <- lm(y ~ x1 * x2)
    graph <- graph_model(model, y=y, x=x1, lines=x2)
    
    expect_is(graph, 'ggplot')
    expect_equal(length(graph$layers), 3)  # geom_point, geom_line, geom_errorbar
    
    expect_equal(ggplot2::quo_name(graph$mapping$x), 'x1')
    expect_equal(ggplot2::quo_name(graph$mapping$y), 'y')
    expect_equal(ggplot2::quo_name(graph$mapping$colour), 'x2')
    
    expect_equal(levels(graph$data$x1), c('-1 SD', '+1 SD'))
    expect_equal(levels(graph$data$x2), c('0', '1'))
})


test_that('lm with continuous x 3-level categorical int. works', {
    set.seed(123)
    x1 <- rnorm(150)
    
    x2 <- c(rep(0, 50), rep(1, 50), rep(2, 50))
    
    set.seed(345)
    y <- x1 * x2 + rnorm(150)
    
    x2 <- factor(x2)
    
    model <- lm(y ~ x1 * x2)
    graph <- graph_model(model, y=y, x=x1, lines=x2)
    
    expect_is(graph, 'ggplot')
    expect_equal(length(graph$layers), 3)  # geom_point, geom_line, geom_errorbar
    
    expect_equal(ggplot2::quo_name(graph$mapping$x), 'x1')
    expect_equal(ggplot2::quo_name(graph$mapping$y), 'y')
    expect_equal(ggplot2::quo_name(graph$mapping$colour), 'x2')
    
    expect_equal(levels(graph$data$x1), c('-1 SD', '+1 SD'))
    expect_equal(levels(graph$data$x2), c('0', '1', '2'))
})


test_that('lm with 3 continuous int. works', {
    set.seed(123)
    x1 <- rnorm(100)
    
    set.seed(234)
    x2 <- rnorm(100)
    
    set.seed(345)
    x3 <- rnorm(100)
    
    set.seed(456)
    y <- x1 * x2 * x3 + rnorm(100)
    
    model <- lm(y ~ x1 * x2 * x3)
    graph <- graph_model(model, y=y, x=x1, lines=x2, split=x3)
    
    expect_is(graph, 'ggplot')
    expect_equal(length(graph$layers), 3)  # geom_point, geom_line, geom_errorbar
    
    expect_equal(ggplot2::quo_name(graph$mapping$x), 'x1')
    expect_equal(ggplot2::quo_name(graph$mapping$y), 'y')
    expect_equal(ggplot2::quo_name(graph$mapping$colour), 'x2')
    expect_equal(names(graph$facet$params$cols), 'x3')
    
    expect_equal(levels(graph$data$x1), c('-1 SD', '+1 SD'))
    expect_equal(levels(graph$data$x2), c('-1 SD', '+1 SD'))
    expect_equal(levels(graph$data$x3), c('x3: -1 SD', 'x3: +1 SD'))
})


test_that('binomial glm works', {
    set.seed(123)
    x1 <- rnorm(100)
    
    set.seed(234)
    x2 <- rnorm(100)
    
    set.seed(345)
    rand <- rnorm(100)
    
    y <- as.numeric((x1 > mean(x1) | x2 > mean(x2)) & rand > mean(rand))
    
    data <- data.frame(x1, x2, y)
    
    model <- glm(y ~ x1 * x2, family='binomial', data)
    graph <- graph_model(model, y=y, x=x1, lines=x2, type='response')
    
    expect_is(graph, 'ggplot')
    expect_equal(length(graph$layers), 3)  # geom_point, geom_line, geom_errorbar
    
    expect_equal(ggplot2::quo_name(graph$mapping$x), 'x1')
    expect_equal(ggplot2::quo_name(graph$mapping$y), 'y')
    expect_equal(ggplot2::quo_name(graph$mapping$colour), 'x2')
    
    expect_equal(levels(graph$data$x1), c('-1 SD', '+1 SD'))
    expect_equal(levels(graph$data$x2), c('-1 SD', '+1 SD'))
})


test_that('aov with 2-way interaction works', {
    x1 <- c(rep(0, 50), rep(1, 50))
    x2 <- rep(c(rep(0, 25), rep(1, 25)), 2)
    
    set.seed(345)
    y <- x1 * x2 + rnorm(100)
    
    x1 <- factor(x1)
    x2 <- factor(x2)
    
    data <- data.frame(x1, x2, y)
    
    model <- aov(y ~ x1 * x2, data)
    graph <- graph_model(model, y=y, x=x1, lines=x2, bargraph=TRUE)
    
    expect_is(graph, 'ggplot')
    expect_equal(length(graph$layers), 2)  # geom_bar, geom_errorbar
    
    expect_equal(ggplot2::quo_name(graph$mapping$x), 'x1')
    expect_equal(ggplot2::quo_name(graph$mapping$y), 'y')
    expect_equal(ggplot2::quo_name(graph$mapping$fill), 'x2')
    
    expect_equal(levels(graph$data$x1), c('0', '1'))
    expect_equal(levels(graph$data$x2), c('0', '1'))
})