A simulated dataset containing a generic outcome varible and three covariates, two of which are subject to a lower limit of detection of 0, with a sample size of 100. See Details for information on how these data were generated.
lod_data_exA data frame with 100 rows and 4 variables:
Outcome
First covariate , no limits of detection
Second covariate, lower limit of detection of 0
Third covariate, lower limit of detection of 0
Each of the covariates were generated independently from 100 independent draws from the standard normal distributon. The outcome variable was generated from a linear model with these three covariates, along with an intercept of 1, a residual variance of 1, and regression coefficients of 1 for each covariates. Then for two of the covariates, to reflect a lower limit of detection of 0, values below this limit were set to 0. This results in a 50 percent probability of being below the limit of detection for each of the two corresponding covariates.