simulate_correlation: Data Simulation

In easystats/bayestestR: Understand and Describe Bayesian Models and Posterior Distributions

Data Simulation

Description

Simulate data with specific characteristics.

Usage

simulate_correlation(n = 100, r = 0.5, mean = 0, sd = 1, names = NULL, ...)

simulate_ttest(n = 100, d = 0.5, names = NULL, ...)

simulate_difference(n = 100, d = 0.5, names = NULL, ...)

Arguments

n	The number of observations to be generated.
r	A value or vector corresponding to the desired correlation coefficients.
mean	A value or vector corresponding to the mean of the variables.
sd	A value or vector corresponding to the SD of the variables.
names	A character vector of desired variable names.
...	Arguments passed to or from other methods.
d	A value or vector corresponding to the desired difference between the groups.

Examples

# Correlation --------------------------------
data <- simulate_correlation(r = 0.5)
plot(data$V1, data$V2)
cor.test(data$V1, data$V2)
summary(lm(V2 ~ V1, data = data))

# Specify mean and SD
data <- simulate_correlation(r = 0.5, n = 50, mean = c(0, 1), sd = c(0.7, 1.7))
cor.test(data$V1, data$V2)
round(c(mean(data$V1), sd(data$V1)), 1)
round(c(mean(data$V2), sd(data$V2)), 1)
summary(lm(V2 ~ V1, data = data))

# Generate multiple variables
cor_matrix <- matrix(
  c(
    1.0, 0.2, 0.4,
    0.2, 1.0, 0.3,
    0.4, 0.3, 1.0
  ),
  nrow = 3
)

data <- simulate_correlation(r = cor_matrix, names = c("y", "x1", "x2"))
cor(data)
summary(lm(y ~ x1, data = data))

# t-test --------------------------------
data <- simulate_ttest(n = 30, d = 0.3)
plot(data$V1, data$V0)
round(c(mean(data$V1), sd(data$V1)), 1)
diff(t.test(data$V1 ~ data$V0)$estimate)
summary(lm(V1 ~ V0, data = data))
summary(glm(V0 ~ V1, data = data, family = "binomial"))

# Difference --------------------------------
data <- simulate_difference(n = 30, d = 0.3)
plot(data$V1, data$V0)
round(c(mean(data$V1), sd(data$V1)), 1)
diff(t.test(data$V1 ~ data$V0)$estimate)
summary(lm(V1 ~ V0, data = data))
summary(glm(V0 ~ V1, data = data, family = "binomial"))

easystats/bayestestR documentation built on Dec. 20, 2024, 8:11 p.m.