example usage in README

README.md

@@ -18,6 +18,21 @@ This package is in production and not yet suitable for production use. We welcom
 
 The development version of this package can be installed via the command:  `devtools::install_github("eebrown/chlorpromazineR")`.
 
+## Usage
+
+Once installed, load package with `library(chlorpromazineR)`. The package's main conversion functions are documented and usage and examples can be seen with `help(to_cpz)` and `help(to_ap)`.
+
+### Convert data to chlorpromazine equivalents
+
+    participant_ID <- c("P01", "P02", "P03", "P04")
+    age <- c(42, 29, 30, 60) # not used in calculation
+    antipsychotic <- c("olanzapine", "olanzapine", "quetiapine", "ziprasidone")
+    dose <- c(10, 12.5, 300, 60)
+    example_oral <- data.frame(participant_ID, age, antipsychotic, dose, 
+                               stringsAsFactors = FALSE)
+    to_cpz(example_oral, ap_label = "antipsychotic", dose_label = "dose", 
+           route = "oral")
+
 ## Disclaimer
 
 This package is not for clinical use. The authors assume no liability. All work must be verified independently. Use at own risk.