| add_clusters | Add cluster number to a data frame | 
| add_factors | Add PCA columns along with summary statistics (KMO and Bartlett test) to a data frame | 
| add_index | Calculate the mean value of multiple items | 
| chatgpt | ChatGPT Adoption Dataset CG-GE-APR23 | 
| codebook | Get variable and value labels from a data set | 
| effect_counts | Output effect sizes and test statistics for count data | 
| effect_metrics | Output effect sizes and test statistics for metric data | 
| html_report | Volker style HTML document format | 
| labs_apply | Set column and value labels | 
| labs_clear | Remove all comments from the selected columns | 
| labs_restore | Restore labels from the codebook store in the codebook attribute. | 
| labs_store | Get the current codebook and store it in the codebook attribute. | 
| pdf_report | Volker style PDF document format | 
| plot_counts | Output a frequency plot | 
| plot_metrics | Output a plot with distribution parameters such as the mean values | 
| report_counts | Create table and plot for categorical variables | 
| report_metrics | Create table and plot for metric variables | 
| tab_counts | Output a frequency table | 
| tab_metrics | Output a table with distribution parameters | 
| theme_vlkr | Define a default theme for volker plots |